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1aa4ad4e |
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10-Apr-2024 |
Tony Lindgren <tony@atomide.com> |
serial: core: Fix missing shutdown and startup for serial base port We are seeing start_tx being called after port shutdown as noted by Jiri. This happens because we are missing the startup and shutdown related functions for the serial base port. Let's fix the issue by adding startup and shutdown functions for the serial base port to block tx flushing for the serial base port when the port is not in use. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Cc: stable <stable@kernel.org> Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20240411055848.38190-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
9cf7ea2e |
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04-Apr-2024 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Clearing the circular buffer before NULLifying it The circular buffer is NULLified in uart_tty_port_shutdown() under the spin lock. However, the PM or other timer based callbacks may still trigger after this event without knowning that buffer pointer is not valid. Since the serial code is a bit inconsistent in checking the buffer state (some rely on the head-tail positions, some on the buffer pointer), it's better to have both aligned, i.e. buffer pointer to be NULL and head-tail possitions to be the same, meaning it's empty. This will prevent asynchronous calls to dereference NULL pointer as reported recently in 8250 case: BUG: kernel NULL pointer dereference, address: 00000cf5 Workqueue: pm pm_runtime_work EIP: serial8250_tx_chars (drivers/tty/serial/8250/8250_port.c:1809) ... ? serial8250_tx_chars (drivers/tty/serial/8250/8250_port.c:1809) __start_tx (drivers/tty/serial/8250/8250_port.c:1551) serial8250_start_tx (drivers/tty/serial/8250/8250_port.c:1654) serial_port_runtime_suspend (include/linux/serial_core.h:667 drivers/tty/serial/serial_port.c:63) __rpm_callback (drivers/base/power/runtime.c:393) ? serial_port_remove (drivers/tty/serial/serial_port.c:50) rpm_suspend (drivers/base/power/runtime.c:447) The proposed change will prevent ->start_tx() to be called during suspend on shut down port. Fixes: 43066e32227e ("serial: port: Don't suspend if the port is still busy") Cc: stable <stable@kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202404031607.2e92eebe-lkp@intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240404150034.41648-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
55559805 |
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25-Mar-2024 |
Tony Lindgren <tony@atomide.com> |
serial: core: Fix regression when runtime PM is not enabled Commit 45a3a8ef8129 ("serial: core: Revert checks for tx runtime PM state") caused a regression for Sun Ultra 60 for the sunsab driver as reported by Nick Bowler <nbowler@draconx.ca>. We need to add back the check runtime PM enabled state for serial port controller device, I wrongly assumed earlier we could just remove it. Fixes: 45a3a8ef8129 ("serial: core: Revert checks for tx runtime PM state") Cc: stable <stable@kernel.org> Reported-by: Nick Bowler <nbowler@draconx.ca> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20240325071649.27040-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
801410b2 |
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04-Mar-2024 |
Peter Collingbourne <pcc@google.com> |
serial: Lock console when calling into driver before registration During the handoff from earlycon to the real console driver, we have two separate drivers operating on the same device concurrently. In the case of the 8250 driver these concurrent accesses cause problems due to the driver's use of banked registers, controlled by LCR.DLAB. It is possible for the setup(), config_port(), pm() and set_mctrl() callbacks to set DLAB, which can cause the earlycon code that intends to access TX to instead access DLL, leading to missed output and corruption on the serial line due to unintended modifications to the baud rate. In particular, for setup() we have: univ8250_console_setup() -> serial8250_console_setup() -> uart_set_options() -> serial8250_set_termios() -> serial8250_do_set_termios() -> serial8250_do_set_divisor() For config_port() we have: serial8250_config_port() -> autoconfig() For pm() we have: serial8250_pm() -> serial8250_do_pm() -> serial8250_set_sleep() For set_mctrl() we have (for some devices): serial8250_set_mctrl() -> omap8250_set_mctrl() -> __omap8250_set_mctrl() To avoid such problems, let's make it so that the console is locked during pre-registration calls to these callbacks, which will prevent the earlycon driver from running concurrently. Remove the partial solution to this problem in the 8250 driver that locked the console only during autoconfig_irq(), as this would result in a deadlock with the new approach. The console continues to be locked during autoconfig_irq() because it can only be called through uart_configure_port(). Although this patch introduces more locking than strictly necessary (and in particular it also locks during the call to rs485_config() which is not affected by this issue as far as I can tell), it follows the principle that it is the responsibility of the generic console code to manage the earlycon handoff by ensuring that earlycon and real console driver code cannot run concurrently, and not the individual drivers. Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Link: https://linux-review.googlesource.com/id/I7cf8124dcebf8618e6b2ee543fa5b25532de55d8 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240304214350.501253-1-pcc@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
30926783 |
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12-Jan-2024 |
Gui-Dong Han <2045gemini@gmail.com> |
serial: core: Fix atomicity violation in uart_tiocmget In uart_tiocmget(): result = uport->mctrl; uart_port_lock_irq(uport); result |= uport->ops->get_mctrl(uport); uart_port_unlock_irq(uport); ... return result; In uart_update_mctrl(): uart_port_lock_irqsave(port, &flags); ... port->mctrl = (old & ~clear) | set; ... port->ops->set_mctrl(port, port->mctrl); ... uart_port_unlock_irqrestore(port, flags); An atomicity violation is identified due to the concurrent execution of uart_tiocmget() and uart_update_mctrl(). After assigning result = uport->mctrl, the mctrl value may change in uart_update_mctrl(), leading to a mismatch between the value returned by uport->ops->get_mctrl(uport) and the mctrl value previously read. This can result in uart_tiocmget() returning an incorrect value. This possible bug is found by an experimental static analysis tool developed by our team, BassCheck[1]. This tool analyzes the locking APIs to extract function pairs that can be concurrently executed, and then analyzes the instructions in the paired functions to identify possible concurrency bugs including data races and atomicity violations. The above possible bug is reported when our tool analyzes the source code of Linux 5.17. To address this issue, it is suggested to move the line result = uport->mctrl inside the uart_port_lock block to ensure atomicity and prevent the mctrl value from being altered during the execution of uart_tiocmget(). With this patch applied, our tool no longer reports the bug, with the kernel configuration allyesconfig for x86_64. Due to the absence of the requisite hardware, we are unable to conduct runtime testing of the patch. Therefore, our verification is solely based on code logic analysis. [1] https://sites.google.com/view/basscheck/ Fixes: c5f4644e6c8b ("[PATCH] Serial: Adjust serial locking") Cc: stable@vger.kernel.org Signed-off-by: Gui-Dong Han <2045gemini@gmail.com> Link: https://lore.kernel.org/r/20240112113624.17048-1-2045gemini@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
74eab89b |
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02-Jan-2024 |
Lino Sanfilippo <l.sanfilippo@kunbus.com> |
serial: core, imx: do not set RS485 enabled if it is not supported If the imx driver cannot support RS485 it nullifies the ports rs485_supported structure. But it still calls uart_get_rs485_mode() which may set the RS485_ENABLED flag nevertheless. This may lead to an attempt to configure RS485 even if it is not supported when the flag is evaluated in uart_configure_port() at port startup. Avoid this by bailing out of uart_get_rs485_mode() if the RS485_ENABLED flag is not supported by the caller. With this fix a check for RTS availability is now obsolete in the imx driver, since it can not evaluate to true any more. So remove this check. Furthermore the explicit nullifcation of rs485_supported is not needed, since the memory has already been set to zeros at allocation. So remove this, too. Fixes: 00d7a00e2a6f ("serial: imx: Fill in rs485_supported") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20240103061818.564-6-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c7398691 |
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02-Jan-2024 |
Lino Sanfilippo <l.sanfilippo@kunbus.com> |
serial: core: make sure RS485 cannot be enabled when it is not supported Some uart drivers specify a rs485_config() function and then decide later to disable RS485 support for some reason (e.g. imx and ar933). In these cases userspace may be able to activate RS485 via TIOCSRS485 nevertheless, since in uart_set_rs485_config() an existing rs485_config() function indicates that RS485 is supported. Make sure that this is not longer possible by checking the uarts rs485_supported.flags instead and bailing out if SER_RS485_ENABLED is not set. Furthermore instead of returning an empty structure return -ENOTTY if the RS485 configuration is requested via TIOCGRS485 but RS485 is not supported. This has a small impact on userspace visibility but it is consistent with the -ENOTTY error for TIOCGRS485. Fixes: e849145e1fdd ("serial: ar933x: Fill in rs485_supported") Fixes: 55e18c6b6d42 ("serial: imx: Remove serial_rs485 sanitization") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-5-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
4afeced5 |
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02-Jan-2024 |
Lino Sanfilippo <l.sanfilippo@kunbus.com> |
serial: core: fix sanitizing check for RTS settings Among other things uart_sanitize_serial_rs485() tests the sanity of the RTS settings in a RS485 configuration that has been passed by userspace. If RTS-on-send and RTS-after-send are both set or unset the configuration is adjusted and RTS-after-send is disabled and RTS-on-send enabled. This however makes only sense if both RTS modes are actually supported by the driver. With commit be2e2cb1d281 ("serial: Sanitize rs485_struct") the code does take the driver support into account but only checks if one of both RTS modes are supported. This may lead to the errorneous result of RTS-on-send being set even if only RTS-after-send is supported. Fix this by changing the implemented logic: First clear all unsupported flags in the RS485 configuration, then adjust an invalid RTS setting by taking into account which RTS mode is supported. Cc: <stable@vger.kernel.org> Fixes: be2e2cb1d281 ("serial: Sanitize rs485_struct") Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-4-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
1a33e33c |
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02-Jan-2024 |
Lino Sanfilippo <l.sanfilippo@kunbus.com> |
serial: core: set missing supported flag for RX during TX GPIO If the RS485 feature RX-during-TX is supported by means of a GPIO set the according supported flag. Otherwise setting this feature from userspace may not be possible, since in uart_sanitize_serial_rs485() the passed RS485 configuration is matched against the supported features and unsupported settings are thereby removed and thus take no effect. Cc: <stable@vger.kernel.org> Fixes: 163f080eb717 ("serial: core: Add option to output RS485 RX_DURING_TX state via GPIO") Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-3-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
07c30ea5 |
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02-Jan-2024 |
Lino Sanfilippo <l.sanfilippo@kunbus.com> |
serial: Do not hold the port lock when setting rx-during-tx GPIO Both the imx and stm32 driver set the rx-during-tx GPIO in rs485_config(). Since this function is called with the port lock held, this can be a problem in case that setting the GPIO line can sleep (e.g. if a GPIO expander is used which is connected via SPI or I2C). Avoid this issue by moving the GPIO setting outside of the port lock into the serial core and thus making it a generic feature. Also with commit c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") the SER_RS485_RX_DURING_TX flag is only set if a rx-during-tx GPIO is _not_ available, which is wrong. Fix this, too. Furthermore reset old GPIO settings in case that changing the RS485 configuration failed. Fixes: c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") Fixes: ca530cfa968c ("serial: imx: Add support for RS485 RX_DURING_TX output GPIO") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-2-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
788aeef3 |
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24-Dec-2023 |
Michael Trimarchi <michael@amarulasolutions.com> |
tty: serial: kgdboc: Fix 8250_* kgdb over serial Check if port type is not PORT_UNKNOWN during poll_init. The kgdboc calls the tty_find_polling_driver that check if the serial is able to use poll_init. The poll_init calls the uart uart_poll_init that try to configure the uart with the selected boot parameters. The uart must be ready before setting parameters. Seems that PORT_UNKNOWN is already used by other functions in serial_core to detect uart status, so use the same to avoid to use it in invalid state. The crash happen for instance in am62x architecture where the 8250 register the platform driver after the 8250 core is initialized. Follow the report crash coming from KGDB Thread 2 received signal SIGSEGV, Segmentation fault. [Switching to Thread 1] _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 584 __raw_writeb(value, PCI_IOBASE + addr); (gdb) bt This section of the code is too early because in this case the omap serial is not probed Thread 2 received signal SIGSEGV, Segmentation fault. [Switching to Thread 1] _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 584 __raw_writeb(value, PCI_IOBASE + addr); (gdb) bt Thread 2 received signal SIGSEGV, Segmentation fault. [Switching to Thread 1] _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 584 __raw_writeb(value, PCI_IOBASE + addr); (gdb) bt 0 _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 1 logic_outb (value=0 '\000', addr=18446739675637874689) at lib/logic_pio.c:299 2 0xffff80008082dfcc in io_serial_out (p=0x0, offset=16760830, value=0) at drivers/tty/serial/8250/8250_port.c:416 3 0xffff80008082fe34 in serial_port_out (value=<optimized out>, offset=<optimized out>, up=<optimized out>) at ./include/linux/serial_core.h:677 4 serial8250_do_set_termios (port=0xffff8000828ee940 <serial8250_ports+1568>, termios=0xffff80008292b93c, old=0x0) at drivers/tty/serial/8250/8250_port.c:2860 5 0xffff800080830064 in serial8250_set_termios (port=0xfffffbfffe800000, termios=0xffbffe, old=0x0) at drivers/tty/serial/8250/8250_port.c:2912 6 0xffff80008082571c in uart_set_options (port=0xffff8000828ee940 <serial8250_ports+1568>, co=0x0, baud=115200, parity=110, bits=8, flow=110) at drivers/tty/serial/serial_core.c:2285 7 0xffff800080828434 in uart_poll_init (driver=0xfffffbfffe800000, line=16760830, options=0xffff8000828f7506 <config+6> "115200n8") at drivers/tty/serial/serial_core.c:2656 8 0xffff800080801690 in tty_find_polling_driver (name=0xffff8000828f7500 <config> "ttyS2,115200n8", line=0xffff80008292ba90) at drivers/tty/tty_io.c:410 9 0xffff80008086c0b0 in configure_kgdboc () at drivers/tty/serial/kgdboc.c:194 10 0xffff80008086c1ec in kgdboc_probe (pdev=0xfffffbfffe800000) at drivers/tty/serial/kgdboc.c:249 11 0xffff8000808b399c in platform_probe (_dev=0xffff000000ebb810) at drivers/base/platform.c:1404 12 0xffff8000808b0b44 in call_driver_probe (drv=<optimized out>, dev=<optimized out>) at drivers/base/dd.c:579 13 really_probe (dev=0xffff000000ebb810, drv=0xffff80008277f138 <kgdboc_platform_driver+48>) at drivers/base/dd.c:658 14 0xffff8000808b0d2c in __driver_probe_device (drv=0xffff80008277f138 <kgdboc_platform_driver+48>, dev=0xffff000000ebb810) at drivers/base/dd.c:800 15 0xffff8000808b0eb8 in driver_probe_device (drv=0xfffffbfffe800000, dev=0xffff000000ebb810) at drivers/base/dd.c:830 16 0xffff8000808b0ff4 in __device_attach_driver (drv=0xffff80008277f138 <kgdboc_platform_driver+48>, _data=0xffff80008292bc48) at drivers/base/dd.c:958 17 0xffff8000808ae970 in bus_for_each_drv (bus=0xfffffbfffe800000, start=0x0, data=0xffff80008292bc48, fn=0xffff8000808b0f3c <__device_attach_driver>) at drivers/base/bus.c:457 18 0xffff8000808b1408 in __device_attach (dev=0xffff000000ebb810, allow_async=true) at drivers/base/dd.c:1030 19 0xffff8000808b16d8 in device_initial_probe (dev=0xfffffbfffe800000) at drivers/base/dd.c:1079 20 0xffff8000808af9f4 in bus_probe_device (dev=0xffff000000ebb810) at drivers/base/bus.c:532 21 0xffff8000808ac77c in device_add (dev=0xfffffbfffe800000) at drivers/base/core.c:3625 22 0xffff8000808b3428 in platform_device_add (pdev=0xffff000000ebb800) at drivers/base/platform.c:716 23 0xffff800081b5dc0c in init_kgdboc () at drivers/tty/serial/kgdboc.c:292 24 0xffff800080014db0 in do_one_initcall (fn=0xffff800081b5dba4 <init_kgdboc>) at init/main.c:1236 25 0xffff800081b0114c in do_initcall_level (command_line=<optimized out>, level=<optimized out>) at init/main.c:1298 26 do_initcalls () at init/main.c:1314 27 do_basic_setup () at init/main.c:1333 28 kernel_init_freeable () at init/main.c:1551 29 0xffff8000810271ec in kernel_init (unused=0xfffffbfffe800000) at init/main.c:1441 30 0xffff800080015e80 in ret_from_fork () at arch/arm64/kernel/entry.S:857 Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com> Link: https://lore.kernel.org/r/20231224131200.266224-1-michael@amarulasolutions.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
6056f20f |
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01-Dec-2023 |
Crescent CY Hsieh <crescentcy.hsieh@moxa.com> |
tty: serial: Add RS422 flag to struct serial_rs485 Add "SER_RS485_MODE_RS422" flag to struct serial_rs485, so that serial port can switch interface into RS422 if supported by using ioctl command "TIOCSRS485". By treating RS422 as a mode of RS485, which means while enabling RS422 there are two flags need to be set (SER_RS485_ENABLED and SER_RS485_MODE_RS422), it would make things much easier. For example some places that checks for "SER_RS485_ENABLED" won't need to be rewritten. Signed-off-by: Crescent CY Hsieh <crescentcy.hsieh@moxa.com> Link: https://lore.kernel.org/r/20231201071554.258607-3-crescentcy.hsieh@moxa.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d4303e0b |
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08-Nov-2023 |
Vamshi Gajjela <vamshigajjela@google.com> |
serial: core: Clean up uart_update_timeout() function Rename the variable size to temp and change its data type from unsigned int to u64 to avoid type casting in multiplication. Remove the intermediate variable frame_time and use temp instead to accommodate the nanoseconds(ns). port->frame_time is an unsigned int, therefore an explicit cast is used to improve readability. Having said this unsigned int is sufficinet to hold frame time duration in nanoseconds for all the standard baudrates. Consider 9600 baud, it takes 1/9600 seconds for one bit, for a total of 10 bits (start, 8-bit data, stop) 10/9600=1.04 ms for 1 byte transfer, frame_time here is 1041667ns. As baudrate increases frame_time decreases, say for 115200 baud it is 86806ns. To avoid costly 64-bit arithmetic we do not upconvert the type for variable frame_time as overflow happens for extremely low baudrates which are impractical and are not used in real-world applications. Signed-off-by: Vamshi Gajjela <vamshigajjela@google.com> Link: https://lore.kernel.org/r/20231109063417.3971005-3-vamshigajjela@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
3a00da02 |
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06-Dec-2023 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: make tty_operations::send_xchar accept u8 char tty_operations::send_xchar is one of the last users of 'char' type for characters in the tty layer. Convert it to u8 now. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: netdev@vger.kernel.org Cc: linux-mmc@vger.kernel.org Cc: linux-bluetooth@vger.kernel.org Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: https://lore.kernel.org/r/20231206073712.17776-5-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
45a3a8ef |
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13-Nov-2023 |
Tony Lindgren <tony@atomide.com> |
serial: core: Revert checks for tx runtime PM state This reverts commit 81a61051e0ce5fd7e09225c0d5985da08c7954a7. With tty and serdev controller moved to be children of the serial core port device, runtime PM usage count of the serdev controller now propagates to the serial hardware controller parent device as expected. Cc: Maximilian Luz <luzmaximilian@gmail.com> Cc: Rob Herring <robh@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20231113080758.30346-2-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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b286f4e8 |
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13-Nov-2023 |
Tony Lindgren <tony@atomide.com> |
serial: core: Move tty and serdev to be children of serial core port device Let's move tty and serdev controller to be children of the serial core port device. This way the runtime PM usage count of a child device propagates to the serial hardware device. The tty and serdev devices are associated with a specific serial port of a serial hardware controller device, and we now have serial core hierarchy of controllers and ports. The tty device moves happily with just a change of the parent device and update of device_find_child() handling. The serdev device init needs some changes to separate the serial hardware controller device from the parent device. With this change the tty devices move under sysfs similar to this x86_64 qemu example of a diff of "find /sys -name ttyS*": /sys/class/tty/ttyS0 /sys/class/tty/ttyS3 /sys/class/tty/ttyS1 -/sys/devices/pnp0/00:04/tty/ttyS0 -/sys/devices/platform/serial8250/tty/ttyS2 -/sys/devices/platform/serial8250/tty/ttyS3 -/sys/devices/platform/serial8250/tty/ttyS1 +/sys/devices/pnp0/00:04/00:04:0/00:04:0.0/tty/ttyS0 +/sys/devices/platform/serial8250/serial8250:0/serial8250:0.3/tty/ttyS3 +/sys/devices/platform/serial8250/serial8250:0/serial8250:0.1/tty/ttyS1 +/sys/devices/platform/serial8250/serial8250:0/serial8250:0.2/tty/ttyS2 If a serdev device is used instead of a tty, it moves in a similar way. Suggested-by: Johan Hovold <johan@kernel.org> Cc: Maximilian Luz <luzmaximilian@gmail.com> Cc: Rob Herring <robh@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20231113080758.30346-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
6f699743 |
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23-Oct-2023 |
Tony Lindgren <tony@atomide.com> |
serial: core: Fix runtime PM handling for pending tx Richard reported that a serial port may end up sometimes with tx data pending in the buffer for long periods of time. Turns out we bail out early on any errors from pm_runtime_get(), including -EINPROGRESS. To fix the issue, we need to ignore -EINPROGRESS as we only care about the runtime PM usage count at this point. We check for an active runtime PM state later on for tx. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Cc: stable <stable@kernel.org> Reported-by: Richard Purdie <richard.purdie@linuxfoundation.org> Cc: Bruce Ashfield <bruce.ashfield@gmail.com> Cc: Mikko Rapeli <mikko.rapeli@linaro.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Randy MacLeod <randy.macleod@windriver.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Richard Purdie <richard.purdie@linuxfoundation.org> Link: https://lore.kernel.org/r/20231023074856.61896-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
23bf72fa |
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10-Oct-2023 |
Max Filippov <jcmvbkbc@gmail.com> |
serial: core: tidy invalid baudrate handling in uart_get_baud_rate uart_get_baud_rate has input parameters 'min' and 'max' limiting the range of acceptable baud rates from the caller's perspective. If neither current or old termios structures have acceptable baud rate setting and 9600 is not in the min/max range either the function returns 0 and issues a warning. However for a UART that does not support speed of 9600 baud this is expected behavior. Clarify that 0 can be (and always could be) returned from the uart_get_baud_rate. Don't issue a warning in that case. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Link: https://lore.kernel.org/r/20231010085926.1021667-2-jcmvbkbc@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
cfb5e0ce |
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05-Oct-2023 |
Alexey Dobriyan <adobriyan@gmail.com> |
serial: initialize retinfo in uart_get_info() If this check ever triggers static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo) { uport = uart_port_check(state); if (!uport) goto out; then all those sysfs users will print stack contents to userspace. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Link: https://lore.kernel.org/r/967b9ef1-fb36-48bf-9e6a-1b99af24c052@p183 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
7cda0b9e |
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03-Oct-2023 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Simplify uart_get_rs485_mode() Simplify uart_get_rs485_mode() by using temporary variable for the GPIO descriptor. With that, use proper type for the flags of the GPIO descriptor. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20231003142346.3072929-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
559c7ff4 |
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14-Sep-2023 |
Thomas Gleixner <tglx@linutronix.de> |
serial: core: Use port lock wrappers When a serial port is used for kernel console output, then all modifications to the UART registers which are done from other contexts, e.g. getty, termios, are interference points for the kernel console. So far this has been ignored and the printk output is based on the principle of hope. The rework of the console infrastructure which aims to support threaded and atomic consoles, requires to mark sections which modify the UART registers as unsafe. This allows the atomic write function to make informed decisions and eventually to restore operational state. It also allows to prevent the regular UART code from modifying UART registers while printk output is in progress. All modifications of UART registers are guarded by the UART port lock, which provides an obvious synchronization point with the console infrastructure. To avoid adding this functionality to all UART drivers, wrap the spin_[un]lock*() invocations for uart_port::lock into helper functions which just contain the spin_[un]lock*() invocations for now. In a subsequent step these helpers will gain the console synchronization mechanisms. Converted with coccinelle. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20230914183831.587273-58-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
81a61051 |
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05-Oct-2023 |
Tony Lindgren <tony@atomide.com> |
serial: core: Fix checks for tx runtime PM state Maximilian reported that surface_serial_hub serdev tx does not work during system suspend. During system suspend, runtime PM gets disabled in __device_suspend_late(), and tx is unable to wake-up the serial core port device that we use to check if tx is safe to start. Johan summarized the regression noting that serdev tx no longer always works as earlier when the serdev device is runtime PM active. The serdev device and the serial core controller devices are siblings of the serial port hardware device. The runtime PM usage count from serdev device does not propagate to the serial core device siblings, it only propagates to the parent. In addition to the tx issue for suspend, testing for the serial core port device can cause an unnecessary delay in enabling tx while waiting for the serial core port device to wake-up. The serial core port device wake-up is only needed to flush pending tx when the serial port hardware device was in runtime PM suspended state. To fix the regression, we need to check the runtime PM state of the parent serial port hardware device for tx instead of the serial core port device. As the serial port device drivers may or may not implement runtime PM, we need to also add a check for pm_runtime_enabled(). Reported-by: Maximilian Luz <luzmaximilian@gmail.com> Cc: stable <stable@kernel.org> Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Maximilian Luz <luzmaximilian@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20231005075644.25936-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
8679328e |
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21-Sep-2023 |
Lukas Wunner <lukas@wunner.de> |
serial: Reduce spinlocked portion of uart_rs485_config() Commit 44b27aec9d96 ("serial: core, 8250: set RS485 termination GPIO in serial core") enabled support for RS485 termination GPIOs behind i2c expanders by setting the GPIO outside of the critical section protected by the port spinlock. Access to the i2c expander may sleep, which caused a splat with the port spinlock held. Commit 7c7f9bc986e6 ("serial: Deassert Transmit Enable on probe in driver-specific way") erroneously regressed that by spinlocking the GPIO manipulation again. Fix by moving uart_rs485_config() (the function manipulating the GPIO) outside of the spinlocked section and acquiring the spinlock inside of uart_rs485_config() for the invocation of ->rs485_config() only. This gets us one step closer to pushing the spinlock down into the ->rs485_config() callbacks which actually need it. (Some callbacks do not want to be spinlocked because they perform sleepable register accesses, see e.g. sc16is7xx_config_rs485().) Stack trace for posterity: Voluntary context switch within RCU read-side critical section! WARNING: CPU: 0 PID: 56 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch Call trace: rcu_note_context_switch __schedule schedule schedule_timeout wait_for_completion_timeout bcm2835_i2c_xfer __i2c_transfer i2c_transfer i2c_transfer_buffer_flags regmap_i2c_write _regmap_raw_write_impl _regmap_bus_raw_write _regmap_write _regmap_update_bits regmap_update_bits_base pca953x_gpio_set_value gpiod_set_raw_value_commit gpiod_set_value_nocheck gpiod_set_value_cansleep uart_rs485_config uart_add_one_port pl011_register_port pl011_probe Fixes: 7c7f9bc986e6 ("serial: Deassert Transmit Enable on probe in driver-specific way") Suggested-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v6.1+ Link: https://lore.kernel.org/r/f3a35967c28b32f3c6432d0aa5936e6a9908282d.1695307688.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
95713967 |
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10-Aug-2023 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: make tty_operations::write()'s count size_t Unify with the rest of the code. Use size_t for counts and ssize_t for retval. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230810091510.13006-30-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
dcaafbe6 |
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10-Aug-2023 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: propagate u8 data to tty_operations::put_char() Data are now typed as u8. Propagate this change to tty_operations::put_char(). Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: NXP Linux Team <linux-imx@nxp.com> Cc: Mathias Nyman <mathias.nyman@intel.com> Link: https://lore.kernel.org/r/20230810091510.13006-29-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
69851e4a |
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10-Aug-2023 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: propagate u8 data to tty_operations::write() Data are now typed as u8. Propagate this change to tty_operations::write(). Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Vaibhav Gupta <vaibhavgupta40@gmail.com> Cc: Jens Taprogge <jens.taprogge@taprogge.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Scott Branden <scott.branden@broadcom.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: David Lin <dtwlin@gmail.com> Cc: Johan Hovold <johan@kernel.org> Cc: Alex Elder <elder@kernel.org> Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: NXP Linux Team <linux-imx@nxp.com> Cc: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Link: https://lore.kernel.org/r/20230810091510.13006-28-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
602c8021 |
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31-Jul-2023 |
Jiri Slaby <jirislaby@kernel.org> |
serial: move WARN_ON() in uart_write() to the condition uart code currently does the following in uart_write() and uart_flush_buffer(): if (cond) { WARN_ON(1); return; } It can be rewritten to more obvious and more readable: if (WARN_ON(cond)) return; Do so. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230731080244.2698-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
1225541c |
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12-Jul-2023 |
Jiri Slaby <jirislaby@kernel.org> |
serial: pass state to __uart_start() directly __uart_start() does not need a tty struct. It works only with uart_state. So pass the latter directly. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230712081811.29004-8-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
df007fa0 |
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12-Jul-2023 |
Jiri Slaby <jirislaby@kernel.org> |
serial: make uart_insert_char() accept u8s Both the character and flag are 8-bit values. So switch from unsigned ints to u8s. The drivers will be cleaned up in the next round. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230712081811.29004-7-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
12ae2359 |
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12-Jul-2023 |
Jiri Slaby <jirislaby@kernel.org> |
serial: convert uart sysrq handling to u8 Propagate u8 from the sysrq code further up to serial's uart_handle_sysrq_char() and friends. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230712081811.29004-6-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
49c80922 |
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02-Jun-2023 |
Tony Lindgren <tony@atomide.com> |
serial: core: Fix error handling for serial_core_ctrl_device_add() Checking for NULL is incorrect as serial_base_ctrl_add() uses ERR_PTR(). Let's also pass any returned error along, there's no reason to translate all errors to -ENODEV. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Signed-off-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230602070007.59268-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d0a39608 |
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01-Jun-2023 |
Steven Price <steven.price@arm.com> |
serial: core: Don't drop port_mutex in serial_core_remove_one_port Commit 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") required the caller to hold port_mutex rather than taking it locally. However the mutex_unlock() call wasn't removed causing the mutex to be dropped unexpectly. Remove the call to mutex_unlock() (and fix up the early return) to restore correct behaviour. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Signed-off-by: Steven Price <steven.price@arm.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20230601105548.29965-1-steven.price@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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84a9582f |
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25-May-2023 |
Tony Lindgren <tony@atomide.com> |
serial: core: Start managing serial controllers to enable runtime PM We want to enable runtime PM for serial port device drivers in a generic way. To do this, we want to have the serial core layer manage the registered physical serial controller devices. To manage serial controllers, let's set up a struct bus and struct device for the serial core controller as suggested by Greg and Jiri. The serial core controller devices are children of the physical serial port device. The serial core controller device is needed to support multiple different kind of ports connected to single physical serial port device. Let's also set up a struct device for the serial core port. The serial core port instances are children of the serial core controller device. With the serial core port device we can now flush pending TX on the runtime PM resume as suggested by Johan. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Jiri Slaby <jirislaby@kernel.org> Suggested-by: Johan Hovold <johan@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230525113034.46880-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
51e45fba |
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25-May-2023 |
John Ogness <john.ogness@linutronix.de> |
serial: core: lock port for start_rx() in uart_resume_port() The only user of the start_rx() callback (qcom_geni) directly calls its own stop_rx() callback. Since stop_rx() requires that the port->lock is taken and interrupts are disabled, the start_rx() callback has the same requirement. Fixes: cfab87c2c271 ("serial: core: Introduce callback for start_rx and do stop_rx in suspend only if this callback implementation is present.") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230525093159.223817-5-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
abcb0cf1f |
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25-May-2023 |
John Ogness <john.ogness@linutronix.de> |
serial: core: lock port for stop_rx() in uart_suspend_port() The uarts_ops stop_rx() callback expects that the port->lock is taken and interrupts are disabled. Fixes: c9d2325cdb92 ("serial: core: Do stop_rx in suspend path for console if console_suspend is disabled") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230525093159.223817-3-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d5b3d02d |
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12-May-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
serial: Make uart_remove_one_port() return void The return value is only ever used as a return value for remove callbacks of platform drivers. This return value is ignored by the driver core. (The only effect is an error message, but uart_remove_one_port() already emitted one in this case.) So the return value isn't used at all and uart_remove_one_port() can be changed to return void without any loss. Also this better matches the Linux device model as remove functions are not supposed to fail. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20230512173810.131447-3-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
63f4c345 |
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19-Apr-2023 |
Tony Lindgren <tony@atomide.com> |
serial: core: Disable uart_start() on uart_remove_one_port() While rebinding a uart device in a loop I noticed we may see a tx related race on uart_remove_one_port(): uart_write from n_tty_write n_tty_write from file_tty_write.constprop.0 file_tty_write.constprop.0 from vfs_write vfs_write from ksys_write ksys_write from ret_fast_syscall Let's disallow tx on port->UPF_DEAD. This flag gets set before we start tearing down the port in uart_remove_one_port(). Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20230419115423.59957-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
9e4f2a80 |
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12-Apr-2023 |
Johan Hovold <johan@kernel.org> |
serial: fix TIOCSRS485 locking The RS485 multipoint addressing support for some reason added a new ADDRB termios cflag which is (only!) updated from one of the RS485 ioctls. Make sure to take the termios rw semaphore for the right ioctl (i.e. set, not get). Fixes: ae50bb275283 ("serial: take termios_rwsem for ->rs485_config() & pass termios as param") Cc: stable@vger.kernel.org # 6.0 Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20230412124811.11217-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
5e227ef2 |
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16-Mar-2023 |
Douglas Anderson <dianders@chromium.org> |
serial: uart_poll_init() should power on the UART On Qualcomm devices which use the "geni" serial driver, kdb/kgdb won't be very happy if you use it but the resources of the port haven't been powered on. Today kdb/kgdb rely on someone else powering the port on. This could be the normal kernel console or an agetty running. Let's fix this to explicitly power things on when setting up a polling driver. Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230316132027.RESEND.1.I106c39498d8094c6f5e7ada42c7db17aa5c64e48@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
044498cd |
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09-Mar-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Remove uart_wait_until_sent() forward declaration Remove unnecessary forward declaration of uart_wait_until_sent(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-9-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
1690ca51 |
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09-Mar-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Rename hw_stopped to old_hw_stopped & improve logic hw_stopped in uart_change_line_settings() stores old hw_stopped, thus rename it appropriately. Alter logic to check first if the hw_stopped was changed, and then pick which function to call if it was because the logic is more obvious that way. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-8-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
b5def43a |
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09-Mar-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Make hw_stopped bool Convert hw_stopped in uart_port to bool because its more appropriate type for how it is used. Also convert the local variable in uart_change_line_settings() caching old hw_stopped to bool. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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826736a6 |
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09-Mar-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Rename uart_change_speed() to uart_change_line_settings() uart_change_speed() changes more than just speed so rename it to more generic uart_change_line_settings(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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8e90cf29 |
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09-Mar-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Move uart_change_speed() earlier Move uart_change_speed() earlier to get rid of its forward declaration. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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807fccf7 |
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09-Mar-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Use B0 instead of implicit zero assumption Compare against B0 rather than assume B0 equals zero, which is true for all archs but explicit B0 makes the code more obvious. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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eff37b5e |
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09-Mar-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Use ARRAY_SIZE() with iso7816 reserved array Instead of a literal, size the for loop iteration based on the actual array using ARRAY_SIZE(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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5701cb8b |
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17-Jan-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
tty: Call ->dtr_rts() parameter active consistently Convert various parameter names for ->dtr_rts() and related functions from onoff, on, and raise to active. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-12-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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968d6457 |
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17-Jan-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Make uart_handle_cts_change() status param bool active Convert uart_handle_cts_change() to bool which is more appropriate than unsigned int. Rename status to active to better describe what the parameter means. While at it, make the comment about the active parameter easier to parse. Cleanup callsites from operations that are not necessary with bool. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-10-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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0388a152 |
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17-Jan-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
tty/serial: Make ->dcd_change()+uart_handle_dcd_change() status bool active Convert status parameter for ->dcd_change() and uart_handle_dcd_change() to bool which matches to how the parameter is used. Rename status to active to better describe what the parameter means. Acked-by: Rodolfo Giometti <giometti@enneenne.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-9-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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5d420399 |
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17-Jan-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
tty: Convert ->dtr_rts() to take bool argument Convert the raise/on parameter in ->dtr_rts() to bool through the callchain. The parameter is used like bool. In USB serial, there remains a few implicit bool -> larger type conversions because some devices use u8 in their control messages. In moxa_tiocmget(), dtr variable was reused for line status which requires int so use a separate variable for status. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-8-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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b300fb26 |
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17-Jan-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
tty: Convert ->carrier_raised() and callchains to bool Return boolean from ->carrier_raised() instead of 0 and 1. Make the return type change also to tty_port_carrier_raised() that makes the ->carrier_raised() call (+ cd variable in moxa into which its return value is stored). Also cleans up a few unnecessary constructs related to this change: return xx ? 1 : 0; -> return xx; if (xx) return 1; return 0; -> return xx; Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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dcd794c6 |
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17-Jan-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Convert uart_{,port_}startup() init_hw param to bool Convert init_hw parameter in uart_startup() and uart_port_startup() to bool as code treats them like bool. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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9b5aa549 |
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17-Jan-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
tty: Cleanup tty_port_set_active() bool parameter Make callers pass true/false consistently for bool val. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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75b20a2a |
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17-Jan-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
tty: Cleamup tty_port_set_suspended() bool parameter Make callers pass true/false consistently for bool val. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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515be7ba |
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17-Jan-2023 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
tty: Cleanup tty_port_set_initialized() bool parameter Make callers pass true/false consistently for bool val. Reviewed-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230117090358.4796-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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163f080e |
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02-Dec-2022 |
Christoph Niedermaier <cniedermaier@dh-electronics.com> |
serial: core: Add option to output RS485 RX_DURING_TX state via GPIO This patch provides a generic GPIO variable for outputting the state of RS485 RX_DURING_TX. The GPIO is defined by the devicetree property "rs485-rx-during-tx-gpios". To use it in a low level serial driver, the evaluation of this variable must be implemented there accordingly. Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com> Link: https://lore.kernel.org/r/20221202104127.122761-2-cniedermaier@dh-electronics.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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3ef5abd9 |
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12-Jan-2023 |
John Ogness <john.ogness@linutronix.de> |
tty: serial: kgdboc: fix mutex locking order for configure_kgdboc() Several mutexes are taken while setting up console serial ports. In particular, the tty_port->mutex and @console_mutex are taken: serial_pnp_probe serial8250_register_8250_port uart_add_one_port (locks tty_port->mutex) uart_configure_port register_console (locks @console_mutex) In order to synchronize kgdb's tty_find_polling_driver() with register_console(), commit 6193bc90849a ("tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console()") takes the @console_mutex. However, this leads to the following call chain (with locking): platform_probe kgdboc_probe configure_kgdboc (locks @console_mutex) tty_find_polling_driver uart_poll_init (locks tty_port->mutex) uart_set_options This is clearly deadlock potential due to the reverse lock ordering. Since uart_set_options() requires holding @console_mutex in order to serialize early initialization of the serial-console lock, take the @console_mutex in uart_poll_init() instead of configure_kgdboc(). Since configure_kgdboc() was using @console_mutex for safe traversal of the console list, change it to use the SRCU iterator instead. Add comments to uart_set_options() kerneldoc mentioning that it requires holding @console_mutex (aka the console_list_lock). Fixes: 6193bc90849a ("tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console()") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> [pmladek@suse.com: Export console_srcu_read_lock_is_held() to fix build kgdboc as a module.] Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230112161213.1434854-1-john.ogness@linutronix.de
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452b9b24 |
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16-Nov-2022 |
John Ogness <john.ogness@linutronix.de> |
serial_core: replace uart_console_enabled() with uart_console_registered() All users of uart_console_enabled() really want to know if a console is registered. It is not reliable to check for CON_ENABLED in order to identify if a console is registered. Use console_is_registered() instead. A _locked() variant is provided because uart_set_options() is always called with the console_list_lock held and must check if a console is registered in order to synchronize with kgdboc. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-23-john.ogness@linutronix.de
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7c7f9bc9 |
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22-Sep-2022 |
Lukas Wunner <lukas@wunner.de> |
serial: Deassert Transmit Enable on probe in driver-specific way When a UART port is newly registered, uart_configure_port() seeks to deassert RS485 Transmit Enable by setting the RTS bit in port->mctrl. However a number of UART drivers interpret a set RTS bit as *assertion* instead of deassertion: Affected drivers include those using serial8250_em485_config() (except 8250_bcm2835aux.c) and some using mctrl_gpio (e.g. imx.c). Since the interpretation of the RTS bit is driver-specific, it is not suitable as a means to centrally deassert Transmit Enable in the serial core. Instead, the serial core must call on drivers to deassert it in their driver-specific way. One way to achieve that is to call ->rs485_config(). It implicitly deasserts Transmit Enable. So amend uart_configure_port() and uart_resume_port() to invoke uart_rs485_config(). That allows removing calls to uart_rs485_config() from drivers' ->probe() hooks and declaring the function static. Skip any invocation of ->set_mctrl() if RS485 is enabled. RS485 has no hardware flow control, so the modem control lines are irrelevant and need not be touched. When leaving RS485 mode, reset the modem control lines to the state stored in port->mctrl. That way, UARTs which are muxed between RS485 and RS232 transceivers drive the lines correctly when switched to RS232. (serial8250_do_startup() historically raises the OUT1 modem signal because otherwise interrupts are not signaled on ancient PC UARTs, but I believe that no longer applies to modern, RS485-capable UARTs and is thus safe to be skipped.) imx.c modifies port->mctrl whenever Transmit Enable is asserted and deasserted. Stop it from doing that so port->mctrl reflects the RS232 line state. 8250_omap.c deasserts Transmit Enable on ->runtime_resume() by calling ->set_mctrl(). Because that is now a no-op in RS485 mode, amend the function to call serial8250_em485_stop_tx(). fsl_lpuart.c retrieves and applies the RS485 device tree properties after registering the UART port. Because applying now happens on registration in uart_configure_port(), move retrieval of the properties ahead of uart_add_one_port(). Link: https://lore.kernel.org/all/20220329085050.311408-1-matthias.schiffer@ew.tq-group.com/ Link: https://lore.kernel.org/all/8f538a8903795f22f9acc94a9a31b03c9c4ccacb.camel@ginzinger.com/ Fixes: d3b3404df318 ("serial: Fix incorrect rs485 polarity on uart open") Cc: stable@vger.kernel.org # v4.14+ Reported-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Reported-by: Roosen Henri <Henri.Roosen@ginzinger.com> Tested-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/2de36eba3fbe11278d5002e4e501afe0ceaca039.1663863805.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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a8c11c15 |
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16-Aug-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
tty: Make ->set_termios() old ktermios const There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220816115739.10928-9-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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bec5b814 |
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16-Aug-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Make ->set_termios() old ktermios const There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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eb9e109d |
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18-Aug-2022 |
Wolfram Sang <wsa+renesas@sang-engineering.com> |
tty: move from strlcpy with unused retval to strscpy Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20220818210113.7469-1-wsa+renesas@sang-engineering.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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9e5f399f |
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28-Jul-2022 |
Jiri Slaby <jirislaby@kernel.org> |
tty: serial: document uart_get_console() This was the only function mentioned in the text, but was neither linked nor documented. So document and link it, so that hyperlinking works in the text. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220728061056.20799-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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987233b3 |
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28-Jul-2022 |
Jiri Slaby <jirislaby@kernel.org> |
tty: serial: serial_core, reformat kernel-doc for functions There are many annotated functions in serial_core.c, but they do not completely conform to the kernel-doc style. So reformat them and link them from the Documentation. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220728061056.20799-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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c4bd17a6 |
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28-Jul-2022 |
Jiri Slaby <jirislaby@kernel.org> |
Documentation: serial: dedup kernel-doc for uart functions Some of the serial (uart_*) functions are documented twice. Once as kernel-doc along their sources and once in Documentation. So deduplicate these texts, merge them into kernel-doc in the sources, and link them using kernel-doc: from the Documentation. To be properly linked and rendered, tabulators had to be removed from the comments. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220728061056.20799-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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4dfd1035 |
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10-Jul-2022 |
Lino Sanfilippo <l.sanfilippo@kunbus.com> |
serial: core: sanitize RS485 delays read from device tree Currently the RTS delays set via device tree are not clamped to a maximum value although the device tree bindings documentation for RS485 claims that only a maximum of 1000 msecs is allowed. So clamp the values to avoid arbitrary high delay settings. However clamp the values to 100 instead of 1000 msecs to be consistent which the maximum that is allowed when setting the delays from userspace via the UART ioctl TIOCSRS485. Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-6-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d8fcd9cf |
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10-Jul-2022 |
Lino Sanfilippo <l.sanfilippo@kunbus.com> |
serial: core: move sanitizing of RS485 delays into own function Move the sanitizing of RS485 delays out of uart_sanitize_serial_rs485() into the new function uart_sanitize_serial_rs485_delays(). Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-5-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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44b27aec |
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10-Jul-2022 |
Lino Sanfilippo <l.sanfilippo@kunbus.com> |
serial: core, 8250: set RS485 termination GPIO in serial core In serial8250_em485_config() the termination GPIO is set with the uart_port spinlock held. This is an issue if setting the GPIO line can sleep (e.g. since the concerning GPIO expander is connected via SPI or I2C). Fix this by setting the termination line outside of the uart_port spinlock in the serial core and using gpiod_set_value_cansleep() which instead of gpiod_set_value() allows it to sleep. Beside fixing the termination GPIO line setting for the 8250 driver this change also makes setting the termination GPIO generic for all UART drivers. Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-4-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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8bec874f |
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03-Jul-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: RS485 termination is supported if DT provides one When DT provides rs485-term, set termination flag as supported. Reviewed-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220704094515.6831-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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0139da50 |
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03-Jul-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Embed rs485_supported to uart_port Embed rs485_supported to uart_port to allow serial core to tweak it as needed. Reviewed-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220704094515.6831-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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4f768e94 |
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24-Jun-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Support for RS-485 multipoint addresses Add support for RS-485 multipoint addressing using 9th bit [*]. The addressing mode is configured through ->rs485_config(). ADDRB in termios indicates 9th bit addressing mode is enabled. In this mode, 9th bit is used to indicate an address (byte) within the communication line. ADDRB can only be enabled/disabled through ->rs485_config() that is also responsible for setting the destination and receiver (filter) addresses. Add traps to detect unwanted changes to struct serial_rs485 layout using static_assert(). [*] Technically, RS485 is just an electronic spec and does not itself specify the 9th bit addressing mode but 9th bit seems at least "semi-standard" way to do addressing with RS485. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220624204210.11112-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ae50bb27 |
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24-Jun-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: take termios_rwsem for ->rs485_config() & pass termios as param To be able to alter ADDRB within ->rs485_config(), take termios_rwsem before calling ->rs485_config() and pass termios. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220624204210.11112-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f9008285 |
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13-Jun-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Drop timeout from uart_port Since commit 31f6bd7fad3b ("serial: Store character timing information to uart_port"), per frame timing information is available on uart_port. Uart port's timeout can be derived from frame_time by multiplying with fifosize. Most callers of uart_poll_timeout are not made under port's lock. To be on the safe side, make sure frame_time is only accessed once. As fifo_size is effectively a constant, it shouldn't cause any issues. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220613113905.22962-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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51ad36ba |
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06-Jun-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: return -EINVAL for non-legacy RS485 flags In order to be add new flags more cleanly and safely, return -EINVAL from TIOCSRS485 ioctl for the flags bits which are not among the current legacy ones. This might cause a regression for userspace as those non-flag bits do not currently trigger -EINVAL. However, it would only occur if the userspace is sending garbage bits so perhaps we'll get away with this change. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220606100433.13793-25-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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596a9171 |
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06-Jun-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Clear rs485 struct when non-RS485 mode is set When SER_RS485_ENABLED is not set, having any other flag/field set in serial_rs485 struct does not have an effect different from not having them set. Thus, make the serial_rs485 struct also match the behavior for all flags, not just SER_RS485_ENABLED. Some drivers do similar clearing of rs485 struct in their rs485_config() already, but not all. This change makes the behavior consistent across drivers. Don't try to validate rs485 struct further when no RS485 is requested, this silences some bogus warnings. This change has (minor) userspace visible impact. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220606100433.13793-24-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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be2e2cb1 |
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06-Jun-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Sanitize rs485_struct Sanitize serial_rs485 struct before calling into rs485_setup. The drivers provide supported_rs485 to help sanitization of the fields. If neither of SER_RS485_RTS_ON_SEND or SER_RS485_RTS_AFTER_SEND supported, don't pretend they can be set to sane settings but clear them both instead. If only one of them is supported it may look tempting to use the one driver supports to set the other, however, the userspace does not have that information readily available so it wouldn't be helpful. While adjusting the documentation, remove also the claim that TIOCGRS485 would call driver specific code. In reality, it does nothing else than copies the stored serial_rs485 structure from uart_port to userspace. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220606100433.13793-23-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2dbd0c14 |
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06-Jun-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Move serial_rs485 sanitization into separate function Add uart_sanitize_serial_rs485() function for sanitizing serial_rs485 structure fields. No functional changes. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220606100433.13793-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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8322b1f5 |
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06-Jun-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Add uart_rs485_config() A few serial drivers make a call to rs485_config() themselves (all these seem to relate to init). Convert them all to use a common helper which makes it easy to make adjustments on tasks related to it as serial_rs485 struct sanitization is going to be added. In pci_fintek_setup() (in 8250_pci.c), the rs485_config() call was made with NULL, however, it can be changed to pass uart_port's rs485 struct. No other callers should pass NULL into rs485_config() so the NULL check can now be eliminated. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220606100433.13793-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f9b11229 |
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28-Jun-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: 8250: Fix PM usage_count for console handover When console is enabled, univ8250_console_setup() calls serial8250_console_setup() before .dev is set to uart_port. Therefore, it will not call pm_runtime_get_sync(). Later, when the actual driver is going to take over univ8250_console_exit() is called. As .dev is already set, serial8250_console_exit() makes pm_runtime_put_sync() call with usage count being zero triggering PM usage count warning (extra debug for univ8250_console_setup(), univ8250_console_exit(), and serial8250_register_ports()): [ 0.068987] univ8250_console_setup ttyS0 nodev [ 0.499670] printk: console [ttyS0] enabled [ 0.717955] printk: console [ttyS0] printing thread started [ 1.960163] serial8250_register_ports assigned dev for ttyS0 [ 1.976830] printk: console [ttyS0] disabled [ 1.976888] printk: console [ttyS0] printing thread stopped [ 1.977073] univ8250_console_exit ttyS0 usage:0 [ 1.977075] serial8250 serial8250: Runtime PM usage count underflow! [ 1.977429] dw-apb-uart.6: ttyS0 at MMIO 0x4010006000 (irq = 33, base_baud = 115200) is a 16550A [ 1.977812] univ8250_console_setup ttyS0 usage:2 [ 1.978167] printk: console [ttyS0] printing thread started [ 1.978203] printk: console [ttyS0] enabled To fix the issue, call pm_runtime_get_sync() in serial8250_register_ports() as soon as .dev is set for an uart_port if it has console enabled. This problem became apparent only recently because 82586a721595 ("PM: runtime: Avoid device usage count underflows") added the warning printout. I confirmed this problem also occurs with v5.18 (w/o the warning printout, obviously). Fixes: bedb404e91bb ("serial: 8250_port: Don't use power management for kernel console") Cc: stable <stable@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/b4f428e9-491f-daf2-2232-819928dc276e@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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cfab87c2 |
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07-Jun-2022 |
Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com> |
serial: core: Introduce callback for start_rx and do stop_rx in suspend only if this callback implementation is present. In suspend sequence there is a need to perform stop_rx during suspend sequence to prevent any asynchronous data over rx line. However this can cause problem to drivers which dont do re-start_rx during set_termios. Add new callback start_rx and perform stop_rx only when implementation of start_rx is present. Also add call to start_rx in resume sequence so that drivers who come across this problem can make use of this framework. Fixes: c9d2325cdb92 ("serial: core: Do stop_rx in suspend path for console if console_suspend is disabled") Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com> Link: https://lore.kernel.org/r/1654627965-1461-2-git-send-email-quic_vnivarth@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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c9d2325c |
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16-May-2022 |
Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com> |
serial: core: Do stop_rx in suspend path for console if console_suspend is disabled For the case of console_suspend disabled, if back to back suspend/resume test is executed, at the end of test, sometimes console would appear to be frozen not responding to input. This would happen because, during resume, rx transactions can come in before system is ready, malfunction of rx happens in turn resulting in console appearing to be stuck. Do a stop_rx in suspend sequence to prevent this. Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com> Link: https://lore.kernel.org/r/1652692810-31148-1-git-send-email-quic_vnivarth@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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31f6bd7f |
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25-Apr-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: Store character timing information to uart_port Struct uart_port currently stores FIFO timeout. Having character timing information readily available is useful. Even serial core itself determines char_time from port->timeout using inverse calculation. Store frame_time directly into uart_port. Character time is stored in nanoseconds to have reasonable precision with high rates. To avoid overflow, 64-bit math is necessary. It might be possible to determine timeout from frame_time by multiplying it with fifosize as needed but only part of the users seem to be protected by a lock. Thus, this patch does not pursue storing only frame_time in uart_port. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220425143410.12703-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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b0e0bd9d |
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27-Feb-2022 |
Tomasz Moń <tomasz.mon@camlingroup.com> |
serial: core: fix tcdrain() with CTS enabled Do not set timeout to twice the approximate amount of time to send the entire FIFO if CTS is enabled. If the caller requested no timeout, e.g. when userspace program called tcdrain(), then wait without any timeout. Premature return from tcdrain() was observed on imx based system which has 32 character long transmitter FIFO with hardware CTS handling. Simple userspace application that reproduces problem has to: * Open tty device, enable hardware flow control (CRTSCTS) * Write data, e.g. 26 bytes * Call tcdrain() to wait for the transmitter * Close tty device The other side of serial connection has to: * Receive some data, e.g. 10 bytes * Set RTS output (CTS input from sender perspective) inactive for at least twice the port timeout * Try to receive remaining data Without this patch, userspace application will finish without any error while the other side of connection will never receive remaining data. Signed-off-by: Tomasz Moń <tomasz.mon@camlingroup.com> Link: https://lore.kernel.org/r/20220228054911.1420221-1-tomasz.mon@camlingroup.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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18c9d4a3 |
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24-Mar-2022 |
Al Cooper <alcooperx@comcast.net> |
serial: When UART is suspended, set RTS to false When flow control is enabled, the UART should set RTS to false during suspend to stop incoming data. Currently, the suspend routine sets the mctrl register in the uart to zero, but leaves the shadow version in the uart_port struct alone so that resume can restore it. This causes a problem later in suspend when serial8250_do_shutdown() is called which uses the shadow mctrl register to clear some additional bits but ends up restoring RTS. The solution is to clear RTS from the shadow version before serial8250_do_shutdown() is called and restore it after. Signed-off-by: Al Cooper <alcooperx@comcast.net> Link: https://lore.kernel.org/r/20220324145620.41573-1-alcooperx@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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0ed12afa |
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09-Apr-2022 |
Lino Sanfilippo <LinoSanfilippo@gmx.de> |
serial: core: move RS485 configuration tasks from drivers into core Several drivers that support setting the RS485 configuration via userspace implement one or more of the following tasks: - in case of an invalid RTS configuration (both RTS after send and RTS on send set or both unset) fall back to enable RTS on send and disable RTS after send - nullify the padding field of the returned serial_rs485 struct - copy the configuration into the uart port struct - limit RTS delays to 100 ms Move these tasks into the serial core to make them generic and to provide a consistent behaviour among all drivers. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Link: https://lore.kernel.org/r/20220410104642.32195-2-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f58c252e |
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14-Mar-2022 |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> |
serial: 8250: fix XOFF/XON sending when DMA is used When 8250 UART is using DMA, x_char (XON/XOFF) is never sent to the wire. After this change, x_char is injected correctly. Create uart_xchar_out() helper for sending the x_char out and accounting related to it. It seems that almost every driver does these same steps with x_char. Except for 8250, however, almost all currently lack .serial_out so they cannot immediately take advantage of this new helper. The downside of this patch is that it might reintroduce the problems some devices faced with mixed DMA/non-DMA transfer which caused revert f967fc8f165f (Revert "serial: 8250_dma: don't bother DMA with small transfers"). However, the impact should be limited to cases with XON/XOFF (that didn't work with DMA capable devices to begin with so this problem is not very likely to cause a major issue, if any at all). Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine") Reported-by: Gilles Buloz <gilles.buloz@kontron.com> Tested-by: Gilles Buloz <gilles.buloz@kontron.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220314091432.4288-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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3f8bab17 |
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03-Mar-2022 |
Jiri Slaby <jirislaby@kernel.org> |
serial: make uart_console_write->putchar()'s character an unsigned char Currently, uart_console_write->putchar's second parameter (the character) is of type int. It makes little sense, provided uart_console_write() accepts the input string as "const char *s" and passes its content -- the characters -- to putchar(). So switch the character's type to unsigned char. We don't use char as that is signed on some platforms. That would cause troubles for drivers which (implicitly) cast the char to u16 when writing to the device. Sign extension would happen in that case and the value written would be completely different to the provided char. DZ is an example of such a driver -- on MIPS, it uses u16 for dz_out in dz_console_putchar(). Note we do the char -> uchar conversion implicitly in uart_console_write(). Provided we do not change size of the data type, sign extension does not happen there, so the problem is void. This makes the types consistent and unified with the rest of the uart layer, which uses unsigned char in most places already. One exception is xmit_buf, but that is going to be converted later. Cc: Paul Cercueil <paul@crapouillou.net> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Ludovic Desroches <ludovic.desroches@microchip.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@orcam.me.uk> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: NXP Linux Team <linux-imx@nxp.com> Cc: Karol Gugala <kgugala@antmicro.com> Cc: Mateusz Holenko <mholenko@antmicro.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Neil Armstrong <narmstrong@baylibre.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Jerome Brunet <jbrunet@baylibre.com> Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Cc: Taichi Sugaya <sugaya.taichi@socionext.com> Cc: Takao Orito <orito.takao@socionext.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Andy Gross <agross@kernel.org> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Cc: Orson Zhai <orsonzhai@gmail.com> Cc: Baolin Wang <baolin.wang7@gmail.com> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Patrice Chotard <patrice.chotard@foss.st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <peter@korsgaard.com> Cc: Michal Simek <michal.simek@xilinx.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> [atmel_serial] Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Paul Cercueil <paul@crapouillou.net> Acked-by: Neil Armstrong <narmstrong@baylibre.com> # meson_serial Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220303080831.21783-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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186ab099 |
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04-Feb-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Drop duplicate NULL check in uart_*shutdown() The free_page(addr), which becomes free_pages(addr, 0) checks addr against 0. No need to repeat this check in the callers. Acked-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220204152808.10808-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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15dc475b |
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24-Jan-2022 |
Jiri Slaby <jirislaby@kernel.org> |
serial: core: clean up EXPORT_SYMBOLs Some EXPORT_SYMBOLs are grouped at one location. Some follow functions they export, but a newline is present before them. Fix all these and move them where they belong. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220124071430.14907-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2dd8a74f |
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22-Jan-2022 |
Lukas Wunner <lukas@wunner.de> |
serial: core: Initialize rs485 RTS polarity already on probe RTS polarity of rs485-enabled ports is currently initialized on uart open via: tty_port_open() tty_port_block_til_ready() tty_port_raise_dtr_rts() # if (C_BAUD(tty)) uart_dtr_rts() uart_port_dtr_rts() There's at least three problems here: First, if no baud rate is set, RTS polarity is not initialized. That's the right thing to do for rs232, but not for rs485, which requires that RTS is deasserted unconditionally. Second, if the DeviceTree property "linux,rs485-enabled-at-boot-time" is present, RTS should be deasserted as early as possible, i.e. on probe. Otherwise it may remain asserted until first open. Third, even though RTS is deasserted on open and close, it may subsequently be asserted by uart_throttle(), uart_unthrottle() or uart_set_termios() because those functions aren't rs485-aware. (Only uart_tiocmset() is.) To address these issues, move RTS initialization from uart_port_dtr_rts() to uart_configure_port(). Prevent subsequent modification of RTS polarity by moving the existing rs485 check from uart_tiocmget() to uart_update_mctrl(). That way, RTS is initialized on probe and then remains unmodified unless the uart transmits data. If rs485 is enabled at runtime (instead of at boot) through a TIOCSRS485 ioctl(), RTS is initialized by the uart driver's ->rs485_config() callback and then likewise remains unmodified. The PL011 driver initializes RTS on uart open and prevents subsequent modification in its ->set_mctrl() callback. That code is obsoleted by the present commit, so drop it. Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Su Bao Cheng <baocheng.su@siemens.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/2d2acaf3a69e89b7bf687c912022b11fd29dfa1e.1642909284.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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93a770b7 |
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02-Jan-2022 |
Lukas Wunner <lukas@wunner.de> |
serial: core: Keep mctrl register state and cached copy in sync struct uart_port contains a cached copy of the Modem Control signals. It is used to skip register writes in uart_update_mctrl() if the new signal state equals the old signal state. It also avoids a register read to obtain the current state of output signals. When a uart_port is registered, uart_configure_port() changes signal state but neglects to keep the cached copy in sync. That may cause a subsequent register write to be incorrectly skipped. Fix it before it trips somebody up. This behavior has been present ever since the serial core was introduced in 2002: https://git.kernel.org/history/history/c/33c0d1b0c3eb So far it was never an issue because the cached copy is initialized to 0 by kzalloc() and when uart_configure_port() is executed, at most DTR has been set by uart_set_options() or sunsu_console_setup(). Therefore, a stable designation seems unnecessary. Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/bceeaba030b028ed810272d55d5fc6f3656ddddb.1641129752.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d3b3404d |
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18-Dec-2021 |
Lukas Wunner <lukas@wunner.de> |
serial: Fix incorrect rs485 polarity on uart open Commit a6845e1e1b78 ("serial: core: Consider rs485 settings to drive RTS") sought to deassert RTS when opening an rs485-enabled uart port. That way, the transceiver does not occupy the bus until it transmits data. Unfortunately, the commit mixed up the logic and *asserted* RTS instead of *deasserting* it: The commit amended uart_port_dtr_rts(), which raises DTR and RTS when opening an rs232 port. "Raising" actually means lowering the signal that's coming out of the uart, because an rs232 transceiver not only changes a signal's voltage level, it also *inverts* the signal. See the simplified schematic in the MAX232 datasheet for an example: https://www.ti.com/lit/ds/symlink/max232.pdf So, to raise RTS on an rs232 port, TIOCM_RTS is *set* in port->mctrl and that results in the signal being driven low. In contrast to rs232, the signal level for rs485 Transmit Enable is the identity, not the inversion: If the transceiver expects a "high" RTS signal for Transmit Enable, the signal coming out of the uart must also be high, so TIOCM_RTS must be *cleared* in port->mctrl. The commit did the exact opposite, but it's easy to see why given the confusing semantics of rs232 and rs485. Fix it. Fixes: a6845e1e1b78 ("serial: core: Consider rs485 settings to drive RTS") Cc: stable@vger.kernel.org # v4.14+ Cc: Rafael Gago Castano <rgc@hms.se> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Su Bao Cheng <baocheng.su@siemens.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/9395767847833f2f3193c49cde38501eeb3b5669.1639821059.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2765852e |
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18-Nov-2021 |
Jiri Slaby <jirislaby@kernel.org> |
tty: serial, join uport checks in uart_port_shutdown() There are two consequent checks of uport != NULL in uart_port_shutdown(). Join these two under a single block. De-multiline the comments when shuffling with them anyway. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20211118071911.12059-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f85e0450 |
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22-Nov-2021 |
Lukas Wunner <lukas@wunner.de> |
serial: 8250: Fix RTS modem control while in rs485 mode Commit f45709df7731 ("serial: 8250: Don't touch RTS modem control while in rs485 mode") sought to prevent user space from interfering with rs485 communication by ignoring a TIOCMSET ioctl() which changes RTS polarity. It did so in serial8250_do_set_mctrl(), which turns out to be too deep in the call stack: When a uart_port is opened, RTS polarity is set by the rs485-aware function uart_port_dtr_rts(). It calls down to serial8250_do_set_mctrl() and that particular RTS polarity change should *not* be ignored. The user-visible result is that on 8250_omap ports which use rs485 with inverse polarity (RTS bit in MCR register is 1 to receive, 0 to send), a newly opened port initially sets up RTS for sending instead of receiving. That's because omap_8250_startup() sets the cached value up->mcr to 0 and omap_8250_restore_regs() subsequently writes it to the MCR register. Due to the commit, serial8250_do_set_mctrl() preserves that incorrect register value: do_sys_openat2 do_filp_open path_openat vfs_open do_dentry_open chrdev_open tty_open uart_open tty_port_open uart_port_activate uart_startup uart_port_startup serial8250_startup omap_8250_startup # up->mcr = 0 uart_change_speed serial8250_set_termios omap_8250_set_termios omap_8250_restore_regs serial8250_out_MCR # up->mcr written tty_port_block_til_ready uart_dtr_rts uart_port_dtr_rts serial8250_set_mctrl omap8250_set_mctrl serial8250_do_set_mctrl # mcr[1] = 1 ignored Fix by intercepting RTS changes from user space in uart_tiocmset() instead. Link: https://lore.kernel.org/linux-serial/20211027111644.1996921-1-baocheng.su@siemens.com/ Fixes: f45709df7731 ("serial: 8250: Don't touch RTS modem control while in rs485 mode") Cc: Chao Zeng <chao.zeng@siemens.com> Cc: stable@vger.kernel.org # v5.7+ Reported-by: Su Bao Cheng <baocheng.su@siemens.com> Reported-by: Jan Kiszka <jan.kiszka@siemens.com> Tested-by: Su Bao Cheng <baocheng.su@siemens.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/21170e622a1aaf842a50b32146008b5374b3dd1d.1637596432.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
00de977f |
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08-Nov-2021 |
Johan Hovold <johan@kernel.org> |
serial: core: fix transmit-buffer reset and memleak Commit 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") converted serial core to use tty_port_close() but failed to notice that the transmit buffer still needs to be freed on final close. Not freeing the transmit buffer means that the buffer is no longer cleared on next open so that any ioctl() waiting for the buffer to drain might wait indefinitely (e.g. on termios changes) or that stale data can end up being transmitted in case tx is restarted. Furthermore, the buffer of any port that has been opened would leak on driver unbind. Note that the port lock is held when clearing the buffer pointer due to the ldisc race worked around by commit a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()"). Also note that the tty-port shutdown() callback is not called for console ports so it is not strictly necessary to free the buffer page after releasing the lock (cf. d72402145ace ("tty/serial: do not free trasnmit buffer page under port lock")). Link: https://lore.kernel.org/r/319321886d97c456203d5c6a576a5480d07c3478.1635781688.git.baruch@tkos.co.il Fixes: 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") Cc: stable@vger.kernel.org # 4.9 Cc: Rob Herring <robh@kernel.org> Reported-by: Baruch Siach <baruch@tkos.co.il> Tested-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20211108085431.12637-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
027b5717 |
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02-Oct-2021 |
Pali Rohár <pali@kernel.org> |
serial: core: Fix initializing and restoring termios speed Since commit edc6afc54968 ("tty: switch to ktermios and new framework") termios speed is no longer stored only in c_cflag member but also in new additional c_ispeed and c_ospeed members. If BOTHER flag is set in c_cflag then termios speed is stored only in these new members. Therefore to correctly restore termios speed it is required to store also ispeed and ospeed members, not only cflag member. In case only cflag member with BOTHER flag is restored then functions tty_termios_baud_rate() and tty_termios_input_baud_rate() returns baudrate stored in c_ospeed / c_ispeed member, which is zero as it was not restored too. If reported baudrate is invalid (e.g. zero) then serial core functions report fallback baudrate value 9600. So it means that in this case original baudrate is lost and kernel changes it to value 9600. Simple reproducer of this issue is to boot kernel with following command line argument: "console=ttyXXX,86400" (where ttyXXX is the device name). For speed 86400 there is no Bnnn constant and therefore kernel has to represent this speed via BOTHER c_cflag. Which means that speed is stored only in c_ospeed and c_ispeed members, not in c_cflag anymore. If bootloader correctly configures serial device to speed 86400 then kernel prints boot log to early console at speed speed 86400 without any issue. But after kernel starts initializing real console device ttyXXX then speed is changed to fallback value 9600 because information about speed was lost. This patch fixes above issue by storing and restoring also ispeed and ospeed members, which are required for BOTHER flag. Fixes: edc6afc54968 ("[PATCH] tty: switch to ktermios and new framework") Cc: stable@vger.kernel.org Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20211002130900.9518-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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9f90a4dd |
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23-Jul-2021 |
Jiri Slaby <jirislaby@kernel.org> |
tty: drop put_tty_driver put_tty_driver() is an alias for tty_driver_kref_put(). There is no need for two exported identical functions, therefore switch all users of old put_tty_driver() to new tty_driver_kref_put() and remove the former for good. Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Cc: Jens Taprogge <jens.taprogge@taprogge.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Scott Branden <scott.branden@broadcom.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Lin <dtwlin@gmail.com> Cc: Johan Hovold <johan@kernel.org> Cc: Alex Elder <elder@kernel.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: NXP Linux Team <linux-imx@nxp.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Felipe Balbi <balbi@kernel.org> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Acked-by: Alex Elder <elder@linaro.org> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Acked-by: David Sterba <dsterba@suse.com> Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210723074317.32690-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
39b7b42b |
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23-Jul-2021 |
Jiri Slaby <jirislaby@kernel.org> |
tty: stop using alloc_tty_driver alloc_tty_driver was deprecated by tty_alloc_driver in commit 7f0bc6a68ed9 (TTY: pass flags to alloc_tty_driver) in 2012. I never got into eliminating alloc_tty_driver until now. So we still have two functions for allocating drivers which might be confusing. So get rid of alloc_tty_driver uses to eliminate it for good in the next patch. Note we need to switch return value checking as tty_alloc_driver uses ERR_PTR. And flags are now a parameter of tty_alloc_driver. Cc: Richard Henderson <rth@twiddle.net>(odd fixer:ALPHA PORT) Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Cc: Jens Taprogge <jens.taprogge@taprogge.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Oliver Neukum <oneukum@suse.com> Cc: Felipe Balbi <balbi@kernel.org> Cc: Johan Hovold <johan@kernel.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Acked-by: David Sterba <dsterba@suse.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210723074317.32690-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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e7b91932 |
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25-Jun-2021 |
Maciej W. Rozycki <macro@orcam.me.uk> |
serial: core: Report magic multiplier extra baud rates Report extra baud rates supported above the base rate for ports with the UPF_MAGIC_MULTIPLIER property, so that people have a way to find out that they can be used with their system, e.g.: Serial: 8250/16550 driver, 5 ports, IRQ sharing enabled printk: console [ttyS0] disabled serial8250.0: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A serial8250.0: ttyS0 extra baud rates supported: 230400, 460800 printk: console [ttyS0] enabled printk: bootconsole [uart8250] disabled serial8250.0: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A serial8250.0: ttyS1 extra baud rates supported: 230400, 460800 serial8250.0: ttyS2 at MMIO 0x1f000900 (irq = 20, base_baud = 230400) is a 16550A Otherwise there is no clear way to figure this out, as the feature is only reported as an obscure TTY flag in bit 16: $ cat /sys/class/tty/ttyS[0-2]/flags 0x10010040 0x10010040 0x90000040 $ Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2106260334170.37803@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
654ee49b |
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10-Jun-2021 |
Jiri Slaby <jirislaby@kernel.org> |
tty: make tty_get_{char,frame}_size available Many tty drivers contain code to compute bits count depending on termios cflags. So extract this code from serial core to two separate tty helper functions: * tty_get_char_size -- only size of a character, without flags, * tty_get_frame_size -- complete size of a frame including flags. In the next patch, calls to these new functions replace many copies of this code. Note that we accept only cflag as a parameter. That's because some callers like pch_uart_startup or sunsab_console_setup don't have at hand termios which we could pass around. Cc: Joe Perches <joe@perches.com> Cc: Johan Hovold <johan@kernel.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210610090247.2593-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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b8be5db5 |
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19-May-2021 |
Jiri Slaby <jirislaby@kernel.org> |
tty/serial: clean up uart_match_port * make parameters const (as they are only read) * return bool (as comparison results are returned) * add \n before final return Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210519072153.3859-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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18ee37e1 |
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19-May-2021 |
Johan Hovold <johan@kernel.org> |
serial: drop irq-flags initialisations There's no need to initialise irq-flags variables before saving the interrupt state. Drop the redundant initialisations from drivers that got this wrong. Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210519092541.10137-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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fff4ef17 |
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05-May-2021 |
Jiri Slaby <jirislaby@kernel.org> |
tty: make tty_operations::chars_in_buffer return uint tty_operations::chars_in_buffer is another hook which is expected to return values >= 0. So make it explicit by the return type too -- use unsigned int. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Acked-by: David Sterba <dsterba@suse.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Cc: Jens Taprogge <jens.taprogge@taprogge.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Lin <dtwlin@gmail.com> Cc: Johan Hovold <johan@kernel.org> Cc: Alex Elder <elder@kernel.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Oliver Neukum <oneukum@suse.com> Cc: Felipe Balbi <balbi@kernel.org> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Link: https://lore.kernel.org/r/20210505091928.22010-27-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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03b3b1a2 |
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05-May-2021 |
Jiri Slaby <jirislaby@kernel.org> |
tty: make tty_operations::write_room return uint Line disciplines expect a positive value or zero returned from tty->ops->write_room (invoked by tty_write_room). So make this assumption explicit by using unsigned int as a return value. Both of tty->ops->write_room and tty_write_room. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com> Acked-by: Alex Elder <elder@linaro.org> Acked-by: Max Filippov <jcmvbkbc@gmail.com> # xtensa Acked-by: David Sterba <dsterba@suse.com> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Chris Zankel <chris@zankel.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Cc: Jens Taprogge <jens.taprogge@taprogge.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Scott Branden <scott.branden@broadcom.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Lin <dtwlin@gmail.com> Cc: Johan Hovold <johan@kernel.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Oliver Neukum <oneukum@suse.com> Cc: Felipe Balbi <balbi@kernel.org> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Link: https://lore.kernel.org/r/20210505091928.22010-23-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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5e722b21 |
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07-May-2021 |
Ondrej Mosnacek <omosnace@redhat.com> |
serial: core: fix suspicious security_locked_down() call The commit that added this check did so in a very strange way - first security_locked_down() is called, its value stored into retval, and if it's nonzero, then an additional check is made for (change_irq || change_port), and if this is true, the function returns. However, if the goto exit branch is not taken, the code keeps the retval value and continues executing the function. Then, depending on whether uport->ops->verify_port is set, the retval value may or may not be reset to zero and eventually the error value from security_locked_down() may abort the function a few lines below. I will go out on a limb and assume that this isn't the intended behavior and that an error value from security_locked_down() was supposed to abort the function only in case (change_irq || change_port) is true. Note that security_locked_down() should be called last in any series of checks, since the SELinux implementation of this hook will do a check against the policy and generate an audit record in case of denial. If the operation was to carry on after calling security_locked_down(), then the SELinux denial record would be bogus. See commit 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown") for how SELinux implements this hook. Fixes: 794edf30ee6c ("lockdown: Lock down TIOCSSERIAL") Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210507115719.140799-1-omosnace@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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79c5966c |
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07-Apr-2021 |
Johan Hovold <johan@kernel.org> |
serial: core: return early on unsupported ioctls Drivers can return -ENOIOCTLCMD when an ioctl is not recognised to tell the upper layers to continue looking for a handler. This is not the case for the RS485 and ISO7816 ioctls whose handlers should return -ENOTTY directly in case a serial driver does not implement the corresponding methods. Fixes: a5f276f10ff7 ("serial_core: Handle TIOC[GS]RS485 ioctls.") Fixes: ad8c0eaa0a41 ("tty/serial_core: add ISO7816 infrastructure") Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210407095208.31838-9-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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8b57b3a1 |
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07-Apr-2021 |
Johan Hovold <johan@kernel.org> |
serial: core: drop redundant TIOCGSERIAL memset Since commit 5099d234a52a ("serial_core: switch to ->[sg]et_serial()") the serial structure passed to uart_get_info() has already have been cleared by the tty layer so drop the redundant memset. Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210407095208.31838-8-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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a157270f |
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08-Feb-2021 |
Ahmed S. Darwish <a.darwish@linutronix.de> |
serial: core: Remove BUG_ON(in_interrupt()) check The usage of in_interrupt() in drivers is phased out for various reasons. In both exported functions where BUG_ON(in_interrupt()) is invoked, there is a mutex_lock() afterwards. mutex_lock() contains a might_sleep() which will already trigger a stack trace if the target functions is called from atomic context. Remove the BUG_ON() and add a "Context: " in the kernel-doc instead. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://lore.kernel.org/r/20210208181615.381861-3-bigeasy@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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0bc1bd09 |
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05-Jan-2021 |
Jiri Slaby <jirislaby@kernel.org> |
tty_port: drop last traces of low_latency The main purpose of tty_port::low_latency was removed in commit a9c3f68f3cd8 (tty: Fix low_latency BUG) back in 2014. It was left in place for drivers as an optional tune knob. But only one driver has been using it until the previous commit. So remove this misconcept completely, given there are no users. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-11-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2f70e49e |
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02-Dec-2020 |
Alexey Kardashevskiy <aik@ozlabs.ru> |
serial_core: Check for port state when tty is in error state At the moment opening a serial device node (such as /dev/ttyS3) succeeds even if there is no actual serial device behind it. Reading/writing/ioctls fail as expected because the uart port is not initialized (the type is PORT_UNKNOWN) and the TTY_IO_ERROR error state bit is set fot the tty. However setting line discipline does not have these checks 8250_port.c (8250 is the default choice made by univ8250_console_init()). As the result of PORT_UNKNOWN, uart_port::iobase is NULL which a platform translates onto some address accessing which produces a crash like below. This adds tty_port_initialized() to uart_set_ldisc() to prevent the crash. Found by syzkaller. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Link: https://lore.kernel.org/r/20201203055834.45838-1-aik@ozlabs.ru Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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e0830dbf |
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09-Sep-2020 |
Johan Hovold <johan@kernel.org> |
serial: core: fix console port-lock regression Fix the port-lock initialisation regression introduced by commit a3cb39d258ef ("serial: core: Allow detach and attach serial device for console") by making sure that the lock is again initialised during console setup. The console may be registered before the serial controller has been probed in which case the port lock needs to be initialised during console setup by a call to uart_set_options(). The console-detach changes introduced a regression in several drivers by effectively removing that initialisation by not initialising the lock when the port is used as a console (which is always the case during console setup). Add back the early lock initialisation and instead use a new console-reinit flag to handle the case where a console is being re-attached through sysfs. The question whether the console-detach interface should have been added in the first place is left for another discussion. Note that the console-enabled check in uart_set_options() is not redundant because of kgdboc, which can end up reinitialising an already enabled console (see commit 42b6a1baa3ec ("serial_core: Don't re-initialize a previously initialized spinlock.")). Fixes: a3cb39d258ef ("serial: core: Allow detach and attach serial device for console") Cc: stable <stable@vger.kernel.org> # 5.7 Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200909143101.15389-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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fe88c648 |
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09-Sep-2020 |
Johan Hovold <johan@kernel.org> |
serial: core: fix port-lock initialisation Commit f743061a85f5 ("serial: core: Initialise spin lock before use in uart_configure_port()") tried to work around a breakage introduced by commit a3cb39d258ef ("serial: core: Allow detach and attach serial device for console") by adding a second initialisation of the port lock when registering the port. As reported by the build robots [1], this doesn't really solve the regression introduced by the console-detach changes and also adds a second redundant initialisation of the lock for normal ports. Start cleaning up this mess by removing the redundant initialisation and making sure that the port lock is again initialised once-only for ports that aren't already in use as a console. [1] https://lore.kernel.org/r/20200802054852.GR23458@shao2-debian Fixes: f743061a85f5 ("serial: core: Initialise spin lock before use in uart_configure_port()") Fixes: a3cb39d258ef ("serial: core: Allow detach and attach serial device for console") Cc: stable <stable@vger.kernel.org> # 5.7 Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200909143101.15389-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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89c65d66 |
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01-Sep-2020 |
Krzysztof Kozlowski <krzk@kernel.org> |
serial: core: Simplify with dev_err_probe() Common pattern of handling deferred probe can be simplified with dev_err_probe(). Less code and the error value gets printed. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Reviewed-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/20200901153100.18827-2-krzk@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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9cfbf7a6 |
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24-Aug-2020 |
Alex Dewar <alex.dewar90@gmail.com> |
serial: core: don't use snprintf() for formatting sysfs attrs As per the documentation (Documentation/filesystems/sysfs.rst), snprintf() should not be used for formatting values returned by sysfs. For all of the instances in serial_core.c, we know that the string will be <PAGE_SIZE in length, so just use sprintf(). Issue identified by Coccinelle. Signed-off-by: Alex Dewar <alex.dewar90@gmail.com> Link: https://lore.kernel.org/r/20200824223932.27709-1-alex.dewar90@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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df561f66 |
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23-Aug-2020 |
Gustavo A. R. Silva <gustavoars@kernel.org> |
treewide: Use fallthrough pseudo-keyword Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
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4ed71add |
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16-Jul-2020 |
Tamseel Shams <m.shams@samsung.com> |
serial: core: Fix Coding Style This patch fixes the following checkpatch error and warning: 1. space required after ',' 2. Missing a blank line after declarations Signed-off-by: Tamseel Shams <m.shams@samsung.com> Link: https://lore.kernel.org/r/20200716115438.9967-1-m.shams@samsung.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f743061a |
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06-Jul-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Initialise spin lock before use in uart_configure_port() The comment near to uart_port_spin_lock_init() says: Ensure that the serial console lock is initialised early. If this port is a console, then the spinlock is already initialised. and there is nothing about enabled or disabled consoles. The commit a3cb39d258ef ("serial: core: Allow detach and attach serial device for console") made a change, which follows the comment, and also to prevent reinitialisation of the lock in use, when user detaches and attaches back the same console device. But this change discovers another issue, that uart_add_one_port() tries to access a spin lock that now may be uninitialised. This happens when a driver expects the serial core to register a console on its behalf. In this case we must initialise a spin lock before use. Fixes: a3cb39d258ef ("serial: core: Allow detach and attach serial device for console") Reported-by: Marc Zyngier <maz@kernel.org> Reported-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Reported-by: Anatoly Pugachev <matorola@gmail.com> Acked-by: Marc Zyngier <maz@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20200706214903.56148-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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08d54703 |
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10-Jun-2020 |
Johan Hovold <johan@kernel.org> |
serial: core: fix sysrq overhead regression Commit 8e20fc391711 ("serial_core: Move sysrq functions from header file") converted the inline sysrq helpers to exported functions which are now called for every received character, interrupt and break signal also on systems without CONFIG_MAGIC_SYSRQ_SERIAL instead of being optimised away by the compiler. Inlining these helpers again also avoids the function call overhead when CONFIG_MAGIC_SYSRQ_SERIAL is enabled (e.g. when the port is not used as a console). Fixes: 8e20fc391711 ("serial_core: Move sysrq functions from header file") Cc: Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by: Johan Hovold <johan@kernel.org> Cc: stable <stable@vger.kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Link: https://lore.kernel.org/r/20200610152232.16925-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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10652a9e |
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10-Jun-2020 |
Johan Hovold <johan@kernel.org> |
Revert "serial: core: Refactor uart_unlock_and_check_sysrq()" This reverts commit da9a5aa3402db0ff3b57216d8dbf2478e1046cae. In order to ease backporting a fix for a sysrq regression, revert this rewrite which was since added on top. The other sysrq helpers now bail out early when sysrq is not enabled; it's better to keep that pattern here as well. Note that the __releases() attribute won't be needed after the follow-on fix either. Fixes: da9a5aa3402d ("serial: core: Refactor uart_unlock_and_check_sysrq()") Cc: stable <stable@vger.kernel.org> Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200610152232.16925-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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167cbce2 |
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10-Jun-2020 |
Johan Hovold <johan@kernel.org> |
serial: core: drop unnecessary gpio include Drop the recently added gpio include from the serial-core header in favour of a forward declaration and instead include the gpio header only where needed. Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20200610155121.14014-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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a7172561 |
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15-Jun-2020 |
Randy Dunlap <rdunlap@infradead.org> |
tty/serial: fix serial_core.c kernel-doc warnings Fix kernel-doc warnings in serial_core.c: ../drivers/tty/serial/serial_core.c:3300: warning: Function parameter or member 'port' not described in 'uart_get_rs485_mode' ../drivers/tty/serial/serial_core.c:3300: warning: Excess function parameter 'dev' description in 'uart_get_rs485_mode' ../drivers/tty/serial/serial_core.c:3300: warning: Excess function parameter 'rs485conf' description in 'uart_get_rs485_mode' Fixes: c150c0f362c1 ("serial: Allow uart_get_rs485_mode() to return errno") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-serial@vger.kernel.org Link: https://lore.kernel.org/r/e170db8e-5c8b-27ac-79a4-81b96ac0ca2d@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d58a2df3 |
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18-May-2020 |
Lukas Wunner <lukas@wunner.de> |
serial: 8250: Support rs485 bus termination GPIO Commit e8759ad17d41 ("serial: uapi: Add support for bus termination") introduced the ability to enable rs485 bus termination from user space. So far the feature is only used by a single driver, 8250_exar.c, using a hardcoded GPIO pin specific to Siemens IOT2040 products. Provide for a more generic solution by allowing specification of an rs485 bus termination GPIO pin in the device tree: Amend the serial core to retrieve the GPIO from the device tree (or ACPI table) and amend the default ->rs485_config() callback for 8250 drivers to change the GPIO on request from user space. Perhaps 8250_exar.c can be converted to the generic approach in a follow-up patch. Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Link: https://lore.kernel.org/r/94c6c800d1ca9fa04766dd1d43a8272c5ad4bedd.1589811297.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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c150c0f3 |
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12-May-2020 |
Lukas Wunner <lukas@wunner.de> |
serial: Allow uart_get_rs485_mode() to return errno We're about to amend uart_get_rs485_mode() to support a GPIO pin for rs485 bus termination. Retrieving the GPIO descriptor may fail, so allow uart_get_rs485_mode() to return an errno and change all callers to check for failure. The GPIO descriptor is going to be stored in struct uart_port. Pass that struct to uart_get_rs485_mode() in lieu of a struct device and struct serial_rs485, both of which are directly accessible from struct uart_port. A few drivers call uart_get_rs485_mode() before setting the struct device pointer in struct uart_port. Shuffle those calls around where necessary. [Heiko Stuebner did the ar933x_uart.c portion, hence his Signed-off-by.] Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/271e814af4b0db3bffbbb74abf2b46b75add4516.1589285873.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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a3cb39d2 |
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17-Feb-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Allow detach and attach serial device for console In the future we would like to disable power management on the serial devices used as kernel consoles to avoid weird behaviour in some cases. However, disabling PM may prevent system to go to deep sleep states, which in its turn leads to the higher power consumption. Tony Lindgren proposed a work around, i.e. allow user to detach such consoles to make PM working again. In case user wants to see what's going on, it also provides a mechanism to attach console back. Link: https://lists.openwall.net/linux-kernel/2018/09/29/65 Suggested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200217114016.49856-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
da9a5aa3 |
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10-Mar-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Refactor uart_unlock_and_check_sysrq() Refactor uart_unlock_and_check_sysrq() to: - explicitly show that we release a port lock which makes static analyzers happy: CHECK drivers/tty/serial/serial_core.c .../serial_core.c:3290:17: warning: context imbalance in 'uart_unlock_and_check_sysrq' - unexpected unlock - use flags instead of irqflags to avoid confusion with IRQ flags - provide one return point - be more compact Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Link: https://lore.kernel.org/r/20200310174337.74109-4-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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e140ef36 |
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10-Mar-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Use uart_console() helper in SysRq code Use uart_console() helper in SysRq code instead of open coded variant. This eliminates the conditional entirely for SERIAL_CORE_CONSOLE=n case. While here, refactor the conditional to be more compact. Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200310174337.74109-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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b18896ff |
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10-Mar-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Print escaped SysRq Magic sequence if enabled It is useful to see on the serial console the magic sequence itself to enable SysRq without rummaging source code. Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200310174337.74109-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2ce5eace |
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10-Mar-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Use string length for SysRq magic sequence Compiler is not happy about using ARRAY_SIZE() in comparison to smaller type: CC drivers/tty/serial/serial_core.o .../serial_core.c: In function ‘uart_try_toggle_sysrq’: .../serial_core.c:3222:24: warning: comparison is always false due to limited range of data type [-Wtype-limits] 3222 | if (++port->sysrq_seq < (ARRAY_SIZE(sysrq_toggle_seq) - 1)) { | ^ Looking at the code it appears that there is an additional weirdness, i.e. use ARRAY_SIZE() against simple string literal. Yes, the idea probably was to allow '\0' in the sequence, but it's impractical: kernel configuration won't accept it to begin with followed by a comment about '\0' before comparison in question. Drop all these by switching to strlen() and convert code accordingly. Note, GCC seems clever enough to calculate string length at compile time. Fixes: 68af43173d3f ("serial/sysrq: Add MAGIC_SYSRQ_SERIAL_SEQUENCE") Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200310174337.74109-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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68af4317 |
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02-Mar-2020 |
Dmitry Safonov <0x7f454c46@gmail.com> |
serial/sysrq: Add MAGIC_SYSRQ_SERIAL_SEQUENCE Many embedded boards have a disconnected TTL level serial which can generate some garbage that can lead to spurious false sysrq detects. Currently, sysrq can be either completely disabled for serial console or always disabled (with CONFIG_MAGIC_SYSRQ_SERIAL), since commit 732dbf3a6104 ("serial: do not accept sysrq characters via serial port") At Arista, we have such boards that can generate BREAK and random garbage. While disabling sysrq for serial console would solve the problem with spurious false sysrq triggers, it's also desirable to have a way to enable sysrq back. As a measure of balance between on and off options, add MAGIC_SYSRQ_SERIAL_SEQUENCE which is a string sequence that can enable sysrq if it follows BREAK on a serial line. The longer the string - the less likely it may be in the garbage. Having the way to enable sysrq was beneficial to debug lockups with a manual investigation in field and on the other side preventing false sysrq detections. Based-on-patch-by: Vasiliy Khoruzhick <vasilykh@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://lore.kernel.org/r/20200302175135.269397-3-dima@arista.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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143c02c8 |
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17-Feb-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Switch to use DEVICE_ATTR_RO() Move device attributes to DEVICE_ATTR_RO() as that would make things a lot more "obvious" what is happening here. Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200217114016.49856-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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643f7d95 |
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14-Feb-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: use octal permissions on module param Symbolic permissions 'S_IRUSR | S_IRGRP' are not preferred. Use octal permissions '0440'. This also makes code shorter. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200214114339.53897-4-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d2403cad |
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14-Feb-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Consolidate spin lock initialization code We have two times duplicated excerpt where we initialize spin lock for UART port. Consolidate it under uart_port_spin_lock_init() helper. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200214114339.53897-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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7a49955a |
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14-Feb-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Introduce uart_console_enabled() helper Introduce uart_console_enabled() helper which checks port to be console and console is registered in the list. Note, this helper will be used in the future as well. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200214114339.53897-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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8e20fc39 |
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09-Jan-2020 |
Dmitry Safonov <0x7f454c46@gmail.com> |
serial_core: Move sysrq functions from header file It's not worth to have them in every serial driver and I'm about to add another helper function. Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://lore.kernel.org/r/20200109215444.95995-2-dima@arista.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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488f49ac |
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06-Jan-2020 |
John Stultz <john.stultz@linaro.org> |
tty: serial_core: Export uart_console_device so it can be used by modules In order to support serial console w/ SERIAL_QCOM_GENI=m, we need to export the uart_console_device() symbol so things will build Cc: Todd Kjos <tkjos@google.com> Cc: Alistair Delva <adelva@google.com> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Amit Pundir <amit.pundir@linaro.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-serial@vger.kernel.org Signed-off-by: John Stultz <john.stultz@linaro.org> Link: https://lore.kernel.org/r/20200107010311.58584-1-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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fb2b9001 |
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12-Dec-2019 |
Sudip Mukherjee <sudipm.mukherjee@gmail.com> |
tty: link tty and port before configuring it as console There seems to be a race condition in tty drivers and I could see on many boot cycles a NULL pointer dereference as tty_init_dev() tries to do 'tty->port->itty = tty' even though tty->port is NULL. 'tty->port' will be set by the driver and if the driver has not yet done it before we open the tty device we can get to this situation. By adding some extra debug prints, I noticed that: 6.650130: uart_add_one_port 6.663849: register_console 6.664846: tty_open 6.674391: tty_init_dev 6.675456: tty_port_link_device uart_add_one_port() registers the console, as soon as it registers, the userspace tries to use it and that leads to tty_open() but uart_add_one_port() has not yet done tty_port_link_device() and so tty->port is not yet configured when control reaches tty_init_dev(). Further look into the code and tty_port_link_device() is done by uart_add_one_port(). After registering the console uart_add_one_port() will call tty_port_register_device_attr_serdev() and tty_port_link_device() is called from this. Call add tty_port_link_device() before uart_configure_port() is done and add a check in tty_port_link_device() so that it only links the port if it has not been done yet. Suggested-by: Jiri Slaby <jslaby@suse.com> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191212131602.29504-1-sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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7d73170e |
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20-Nov-2019 |
Jiangfeng Xiao <xiaojiangfeng@huawei.com> |
serial: serial_core: Perform NULL checks for break_ctl ops Doing fuzz test on sbsa uart device, causes a kernel crash due to NULL pointer dereference: ------------[ cut here ]------------ Unable to handle kernel paging request at virtual address fffffffffffffffc pgd = ffffffe331723000 [fffffffffffffffc] *pgd=0000002333595003, *pud=0000002333595003, *pmd=00000 Internal error: Oops: 96000005 [#1] PREEMPT SMP Modules linked in: ping(O) jffs2 rtos_snapshot(O) pramdisk(O) hisi_sfc(O) Drv_Nandc_K(O) Drv_SysCtl_K(O) Drv_SysClk_K(O) bsp_reg(O) hns3(O) hns3_uio_enet(O) hclgevf(O) hclge(O) hnae3(O) mdio_factory(O) mdio_registry(O) mdio_dev(O) mdio(O) hns3_info(O) rtos_kbox_panic(O) uart_suspend(O) rsm(O) stp llc tunnel4 xt_tcpudp ipt_REJECT nf_reject_ipv4 iptable_filter ip_tables x_tables sd_mod xhci_plat_hcd xhci_pci xhci_hcd usbmon usbhid usb_storage ohci_platform ohci_pci ohci_hcd hid_generic hid ehci_platform ehci_pci ehci_hcd vfat fat usbcore usb_common scsi_mod yaffs2multi(O) ext4 jbd2 ext2 mbcache ofpart i2c_dev i2c_core uio ubi nand nand_ecc nand_ids cfi_cmdset_0002 cfi_cmdset_0001 cfi_probe gen_probe cmdlinepart chipreg mtdblock mtd_blkdevs mtd nfsd auth_rpcgss oid_registry nfsv3 nfs nfs_acl lockd sunrpc grace autofs4 CPU: 2 PID: 2385 Comm: tty_fuzz_test Tainted: G O 4.4.193 #1 task: ffffffe32b23f110 task.stack: ffffffe32bda4000 PC is at uart_break_ctl+0x44/0x84 LR is at uart_break_ctl+0x34/0x84 pc : [<ffffff8393196098>] lr : [<ffffff8393196088>] pstate: 80000005 sp : ffffffe32bda7cc0 x29: ffffffe32bda7cc0 x28: ffffffe32b23f110 x27: ffffff8393402000 x26: 0000000000000000 x25: ffffffe32b233f40 x24: ffffffc07a8ec680 x23: 0000000000005425 x22: 00000000ffffffff x21: ffffffe33ed73c98 x20: 0000000000000000 x19: ffffffe33ed94168 x18: 0000000000000004 x17: 0000007f92ae9d30 x16: ffffff8392fa6064 x15: 0000000000000010 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000020 x10: 0000007ffdac1708 x9 : 0000000000000078 x8 : 000000000000001d x7 : 0000000052a64887 x6 : ffffffe32bda7e08 x5 : ffffffe32b23c000 x4 : 0000005fbc5b0000 x3 : ffffff83938d5018 x2 : 0000000000000080 x1 : ffffffe32b23c040 x0 : ffffff83934428f8 virtual start addr offset is 38ac00000 module base offset is 2cd4cf1000 linear region base offset is : 0 Process tty_fuzz_test (pid: 2385, stack limit = 0xffffffe32bda4000) Stack: (0xffffffe32bda7cc0 to 0xffffffe32bda8000) 7cc0: ffffffe32bda7cf0 ffffff8393177718 ffffffc07a8ec680 ffffff8393196054 7ce0: 000000001739f2e0 0000007ffdac1978 ffffffe32bda7d20 ffffff8393179a1c 7d00: 0000000000000000 ffffff8393c0a000 ffffffc07a8ec680 cb88537fdc8ba600 7d20: ffffffe32bda7df0 ffffff8392fa5a40 ffffff8393c0a000 0000000000005425 7d40: 0000007ffdac1978 ffffffe32b233f40 ffffff8393178dcc 0000000000000003 7d60: 000000000000011d 000000000000001d ffffffe32b23f110 000000000000029e 7d80: ffffffe34fe8d5d0 0000000000000000 ffffffe32bda7e14 cb88537fdc8ba600 7da0: ffffffe32bda7e30 ffffff8393042cfc ffffff8393c41720 ffffff8393c46410 7dc0: ffffff839304fa68 ffffffe32b233f40 0000000000005425 0000007ffdac1978 7de0: 000000000000011d cb88537fdc8ba600 ffffffe32bda7e70 ffffff8392fa60cc 7e00: 0000000000000000 ffffffe32b233f40 ffffffe32b233f40 0000000000000003 7e20: 0000000000005425 0000007ffdac1978 ffffffe32bda7e70 ffffff8392fa60b0 7e40: 0000000000000280 ffffffe32b233f40 ffffffe32b233f40 0000000000000003 7e60: 0000000000005425 cb88537fdc8ba600 0000000000000000 ffffff8392e02e78 7e80: 0000000000000280 0000005fbc5b0000 ffffffffffffffff 0000007f92ae9d3c 7ea0: 0000000060000000 0000000000000015 0000000000000003 0000000000005425 7ec0: 0000007ffdac1978 0000000000000000 00000000a54c910e 0000007f92b95014 7ee0: 0000007f92b95090 0000000052a64887 000000000000001d 0000000000000078 7f00: 0000007ffdac1708 0000000000000020 0000000000000000 0000000000000000 7f20: 0000000000000000 0000000000000010 000000556acf0090 0000007f92ae9d30 7f40: 0000000000000004 000000556acdef10 0000000000000000 000000556acdebd0 7f60: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 7f80: 0000000000000000 0000000000000000 0000000000000000 0000007ffdac1840 7fa0: 000000556acdedcc 0000007ffdac1840 0000007f92ae9d3c 0000000060000000 7fc0: 0000000000000000 0000000000000000 0000000000000003 000000000000001d 7fe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 Call trace: Exception stack(0xffffffe32bda7ab0 to 0xffffffe32bda7bf0) 7aa0: 0000000000001000 0000007fffffffff 7ac0: ffffffe32bda7cc0 ffffff8393196098 0000000080000005 0000000000000025 7ae0: ffffffe32b233f40 ffffff83930d777c ffffffe32bda7b30 ffffff83930d777c 7b00: ffffffe32bda7be0 ffffff83938d5000 ffffffe32bda7be0 ffffffe32bda7c20 7b20: ffffffe32bda7b60 ffffff83930d777c ffffffe32bda7c10 ffffff83938d5000 7b40: ffffffe32bda7c10 ffffffe32bda7c50 ffffff8393c0a000 ffffffe32b23f110 7b60: ffffffe32bda7b70 ffffff8392e09df4 ffffffe32bda7bb0 cb88537fdc8ba600 7b80: ffffff83934428f8 ffffffe32b23c040 0000000000000080 ffffff83938d5018 7ba0: 0000005fbc5b0000 ffffffe32b23c000 ffffffe32bda7e08 0000000052a64887 7bc0: 000000000000001d 0000000000000078 0000007ffdac1708 0000000000000020 7be0: 0000000000000000 0000000000000000 [<ffffff8393196098>] uart_break_ctl+0x44/0x84 [<ffffff8393177718>] send_break+0xa0/0x114 [<ffffff8393179a1c>] tty_ioctl+0xc50/0xe84 [<ffffff8392fa5a40>] do_vfs_ioctl+0xc4/0x6e8 [<ffffff8392fa60cc>] SyS_ioctl+0x68/0x9c [<ffffff8392e02e78>] __sys_trace_return+0x0/0x4 Code: b9410ea0 34000160 f9408aa0 f9402814 (b85fc280) ---[ end trace 8606094f1960c5e0 ]--- Kernel panic - not syncing: Fatal exception Fix this problem by adding NULL checks prior to calling break_ctl ops. Signed-off-by: Jiangfeng Xiao <xiaojiangfeng@huawei.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/1574263133-28259-1-git-send-email-xiaojiangfeng@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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dd8b7a1d |
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15-Oct-2019 |
Michal Simek <michal.simek@xilinx.com> |
Revert "serial: core: Use cons->index for preferred console registration" This reverts commit 91daae03188e0dd1da3c1b599df4ce7539d5a69f. The origin patch is causing an issue on r8a7791/koelsch and r8a7795/salvator-xs platforms where cons->index is not initialized to expected value. It is safer to revert this patch for now till it is clear why this is happening. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Link: https://lore.kernel.org/r/59f51af6bb03fce823663764d17ad0291aa01ab2.1571222199.git.michal.simek@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ff30283a |
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08-Oct-2019 |
Randy Dunlap <rdunlap@infradead.org> |
serial: fix kernel-doc warning in comments Fix Sphinx warning in serial_core.c: ../drivers/tty/serial/serial_core.c:1969: WARNING: Definition list ends without a blank line; unexpected unindent. Fixes: 73abaf87f01b ("serial: earlycon: Refactor parse_options into serial core") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/e989641c-224a-1090-e596-e7cc800bed44@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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91daae03 |
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02-Sep-2019 |
Michal Simek <michal.simek@xilinx.com> |
serial: core: Use cons->index for preferred console registration The reason for this patch is xilinx_uartps driver which create one dynamic instance per IP with unique major and minor combinations. drv->nr is in this case all the time setup to 1. That means that uport->line is all the time setup to 0 and drv->tty_driver->name_base is doing shift in name to for example ttyPS3. register_console() is looping over console_cmdline array and looking for proper name/index combination which is in our case ttyPS/3. That's why every instance of driver needs to be registered with proper combination of name/number (ttyPS/3). Using uport->line is doing registration with ttyPS/0 which is wrong that's why proper console index should be used which is in cons->index field. Also it is visible that recording console should be done based on information about console not about the port but in most cases numbers are the same and xilinx_uartps is only one exception now. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Link: https://lore.kernel.org/r/4a877f1c7189a7c45b59a6ebfc3de607e8758949.1567434470.git.michal.simek@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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794edf30 |
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19-Aug-2019 |
David Howells <dhowells@redhat.com> |
lockdown: Lock down TIOCSSERIAL Lock down TIOCSSERIAL as that can be used to change the ioport and irq settings on a serial port. This only appears to be an issue for the serial drivers that use the core serial code. All other drivers seem to either ignore attempts to change port/irq or give an error. Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Matthew Garrett <mjg59@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> cc: Jiri Slaby <jslaby@suse.com> Cc: linux-serial@vger.kernel.org Signed-off-by: James Morris <jmorris@namei.org>
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13b18d35 |
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08-May-2019 |
Serge Semin <fancer.lancer@gmail.com> |
tty: serial_core: Set port active bit in uart_port_activate A bug was introduced by commit b3b576461864 ("tty: serial_core: convert uart_open to use tty_port_open"). It caused a constant warning printed into the system log regarding the tty and port counter mismatch: [ 21.644197] ttyS ttySx: tty_port_close_start: tty->count = 1 port count = 2 in case if session hangup was detected so the warning is printed starting from the second open-close iteration. Particularly the problem was discovered in situation when there is a serial tty device without hardware back-end being setup. It is considered by the tty-serial subsystems as a hardware problem with session hang up. In this case uart_startup() will return a positive value with TTY_IO_ERROR flag set in corresponding tty_struct instance. The same value will get passed to be returned from the activate() callback and then being returned from tty_port_open(). But since in this case tty_port_block_til_ready() isn't called the TTY_PORT_ACTIVE flag isn't set (while the method had been called before tty_port_open conversion was introduced and the rest of the subsystem code expected the bit being set in this case), which prevents the uart_hangup() method to perform any cleanups including the tty port counter setting to zero. So the next attempt to open/close the tty device will discover the counters mismatch. In order to fix the problem we need to manually set the TTY_PORT_ACTIVE flag in case if uart_startup() returned a positive value. In this case the hang up procedure will perform a full set of cleanup actions including the port ref-counter resetting. Fixes: b3b576461864 "tty: serial_core: convert uart_open to use tty_port_open" Signed-off-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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050dfc09 |
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22-Apr-2019 |
Sergey Organov <sorganov@gmail.com> |
tty: serial_core: fix error code returned by uart_register_driver() uart_register_driver() returned -ENOMEM on any error, even when tty_register_driver() call returned another one, such as -EBUSY. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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4cdd17ba |
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17-Apr-2019 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial_core, add ->install We need to compute the uart state only on the first open. This is usually what is done in the ->install hook. serial_core used to do this in ->open on every open. So move it to ->install. As a side effect, it ensures the state is set properly in the window after tty_init_dev is called, but before uart_open. This fixes a bunch of races between tty_open and flush_to_ldisc we were dealing with recently. One of such bugs was attempted to fix in commit fedb5760648a (serial: fix race between flush_to_ldisc and tty_open), but it only took care of a couple of functions (uart_start and uart_unthrottle). I was able to reproduce the crash on a SLE system, but in uart_write_room which is also called from flush_to_ldisc via process_echoes. I was *unable* to reproduce the bug locally. It is due to having this patch in my queue since 2012! general protection fault: 0000 [#1] SMP KASAN PTI CPU: 1 PID: 5 Comm: kworker/u4:0 Tainted: G L 4.12.14-396-default #1 SLE15-SP1 (unreleased) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c89-prebuilt.qemu.org 04/01/2014 Workqueue: events_unbound flush_to_ldisc task: ffff8800427d8040 task.stack: ffff8800427f0000 RIP: 0010:uart_write_room+0xc4/0x590 RSP: 0018:ffff8800427f7088 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 000000000000002f RSI: 00000000000000ee RDI: ffff88003888bd90 RBP: ffffffffb9545850 R08: 0000000000000001 R09: 0000000000000400 R10: ffff8800427d825c R11: 000000000000006e R12: 1ffff100084fee12 R13: ffffc900004c5000 R14: ffff88003888bb28 R15: 0000000000000178 FS: 0000000000000000(0000) GS:ffff880043300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561da0794148 CR3: 000000000ebf4000 CR4: 00000000000006e0 Call Trace: tty_write_room+0x6d/0xc0 __process_echoes+0x55/0x870 n_tty_receive_buf_common+0x105e/0x26d0 tty_ldisc_receive_buf+0xb7/0x1c0 tty_port_default_receive_buf+0x107/0x180 flush_to_ldisc+0x35d/0x5c0 ... 0 in rbx means tty->driver_data is NULL in uart_write_room. 0x178 is tried to be dereferenced (0x178 >> 3 is 0x2f in rdx) at uart_write_room+0xc4. 0x178 is exactly (struct uart_state *)NULL->refcount used in uart_port_lock from uart_write_room. So revert the upstream commit here as my local patch should fix the whole family. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Li RongQing <lirongqing@baidu.com> Cc: Wang Li <wangli39@baidu.com> Cc: Zhang Yu <zhangyu31@baidu.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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c7a6b9e4 |
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27-Mar-2019 |
Hariprasad Kelam <hariprasad.kelam@gmail.com> |
tty:serial_core: Spelling mistake fix spelling mistake "overriden" -> "overridden" This fix resolves warning reported by checkpatch tool. Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com> Reviewed-by: Mukesh Ojha <mojha@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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b289c496 |
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18-Feb-2019 |
Chengguang Xu <cgxu519@gmx.com> |
tty: serial: remove redundant likely annotation unlikely has already included in IS_ERR(), so just remove redundant likely annotation. Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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fedb5760 |
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31-Jan-2019 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
serial: fix race between flush_to_ldisc and tty_open There still is a race window after the commit b027e2298bd588 ("tty: fix data race between tty_init_dev and flush of buf"), and we encountered this crash issue if receive_buf call comes before tty initialization completes in tty_open and tty->driver_data may be NULL. CPU0 CPU1 ---- ---- tty_open tty_init_dev tty_ldisc_unlock schedule flush_to_ldisc receive_buf tty_port_default_receive_buf tty_ldisc_receive_buf n_tty_receive_buf_common __receive_buf uart_flush_chars uart_start /*tty->driver_data is NULL*/ tty->ops->open /*init tty->driver_data*/ it can be fixed by extending ldisc semaphore lock in tty_init_dev to driver_data initialized completely after tty->ops->open(), but this will lead to get lock on one function and unlock in some other function, and hard to maintain, so fix this race only by checking tty->driver_data when receiving, and return if tty->driver_data is NULL, and n_tty_receive_buf_common maybe calls uart_unthrottle, so add the same check. Because the tty layer knows nothing about the driver associated with the device, the tty layer can not do anything here, it is up to the tty driver itself to check for this type of race. Fix up the serial driver to correctly check to see if it is finished binding with the device when being called, and if not, abort the tty calls. [Description and problem report and testing from Li RongQing, I rewrote the patch to be in the serial layer, not in the tty core - gregkh] Reported-by: Li RongQing <lirongqing@baidu.com> Tested-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Wang Li <wangli39@baidu.com> Signed-off-by: Zhang Yu <zhangyu31@baidu.com> Signed-off-by: Li RongQing <lirongqing@baidu.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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aff9cf59 |
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16-Jan-2019 |
Samir Virmani <samir@embedur.com> |
uart: Fix crash in uart_write and uart_put_char We were experiencing a crash similar to the one reported as part of commit:a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") in our testbed as well. We continue to observe the same crash after integrating the commit a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") On reviewing the change, the port lock should be taken prior to checking for if (!circ->buf) in fn. __uart_put_char and other fns. that update the buffer uart_state->xmit. Traceback: [11/27/2018 06:24:32.4870] Unable to handle kernel NULL pointer dereference at virtual address 0000003b [11/27/2018 06:24:32.4950] PC is at memcpy+0x48/0x180 [11/27/2018 06:24:32.4950] LR is at uart_write+0x74/0x120 [11/27/2018 06:24:32.4950] pc : [<ffffffc0002e6808>] lr : [<ffffffc0003747cc>] pstate: 000001c5 [11/27/2018 06:24:32.4950] sp : ffffffc076433d30 [11/27/2018 06:24:32.4950] x29: ffffffc076433d30 x28: 0000000000000140 [11/27/2018 06:24:32.4950] x27: ffffffc0009b9d5e x26: ffffffc07ce36580 [11/27/2018 06:24:32.4950] x25: 0000000000000000 x24: 0000000000000140 [11/27/2018 06:24:32.4950] x23: ffffffc000891200 x22: ffffffc01fc34000 [11/27/2018 06:24:32.4950] x21: 0000000000000fff x20: 0000000000000076 [11/27/2018 06:24:32.4950] x19: 0000000000000076 x18: 0000000000000000 [11/27/2018 06:24:32.4950] x17: 000000000047cf08 x16: ffffffc000099e68 [11/27/2018 06:24:32.4950] x15: 0000000000000018 x14: 776d726966205948 [11/27/2018 06:24:32.4950] x13: 50203a6c6974755f x12: 74647075205d3333 [11/27/2018 06:24:32.4950] x11: 3a35323a36203831 x10: 30322f37322f3131 [11/27/2018 06:24:32.4950] x9 : 5b205d303638342e x8 : 746164206f742070 [11/27/2018 06:24:32.4950] x7 : 7520736920657261 x6 : 000000000000003b [11/27/2018 06:24:32.4950] x5 : 000000000000817a x4 : 0000000000000008 [11/27/2018 06:24:32.4950] x3 : 2f37322f31312a5b x2 : 000000000000006e [11/27/2018 06:24:32.4950] x1 : ffffffc0009b9cf0 x0 : 000000000000003b [11/27/2018 06:24:32.4950] CPU2: stopping [11/27/2018 06:24:32.4950] CPU: 2 PID: 0 Comm: swapper/2 Tainted: P D O 4.1.51 #3 [11/27/2018 06:24:32.4950] Hardware name: Broadcom-v8A (DT) [11/27/2018 06:24:32.4950] Call trace: [11/27/2018 06:24:32.4950] [<ffffffc0000883b8>] dump_backtrace+0x0/0x150 [11/27/2018 06:24:32.4950] [<ffffffc00008851c>] show_stack+0x14/0x20 [11/27/2018 06:24:32.4950] [<ffffffc0005ee810>] dump_stack+0x90/0xb0 [11/27/2018 06:24:32.4950] [<ffffffc00008e844>] handle_IPI+0x18c/0x1a0 [11/27/2018 06:24:32.4950] [<ffffffc000080c68>] gic_handle_irq+0x88/0x90 Fixes: a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") Cc: stable <stable@vger.kernel.org> Signed-off-by: Samir Virmani <samir@embedur.com> Acked-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d7240214 |
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12-Dec-2018 |
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> |
tty/serial: do not free trasnmit buffer page under port lock LKP has hit yet another circular locking dependency between uart console drivers and debugobjects [1]: CPU0 CPU1 rhltable_init() __init_work() debug_object_init uart_shutdown() /* db->lock */ /* uart_port->lock */ debug_print_object() free_page() printk() call_console_drivers() debug_check_no_obj_freed() /* uart_port->lock */ /* db->lock */ debug_print_object() So there are two dependency chains: uart_port->lock -> db->lock And db->lock -> uart_port->lock This particular circular locking dependency can be addressed in several ways: a) One way would be to move debug_print_object() out of db->lock scope and, thus, break the db->lock -> uart_port->lock chain. b) Another one would be to free() transmit buffer page out of db->lock in UART code; which is what this patch does. It makes sense to apply a) and b) independently: there are too many things going on behind free(), none of which depend on uart_port->lock. The patch fixes transmit buffer page free() in uart_shutdown() and, additionally, in uart_port_startup() (as was suggested by Dmitry Safonov). [1] https://lore.kernel.org/lkml/20181211091154.GL23332@shao2-debian/T/#u Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Waiman Long <longman@redhat.com> Cc: Dmitry Safonov <dima@arista.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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7ee32965 |
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13-Sep-2018 |
Al Viro <viro@zeniv.linux.org.uk> |
kill TIOCSER[SG]WILD the only user is very old setserial rc script and even that (as far back as MCC Interim, AFAICS) doesn't actually fail - just gives one message during the boot ("Cannot scan for wild interrupts") and proceeds past that just fine. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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5099d234 |
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11-Sep-2018 |
Al Viro <viro@zeniv.linux.org.uk> |
serial_core: switch to ->[sg]et_serial() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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817e9bc8 |
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04-Oct-2018 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
Revert "serial:serial_core: Allow use of CTS for PPS line discipline" This reverts commit c550f01c810f2197c98e6e3103f81797f5e063be. Turns out the samsung tty driver is mucking around in the "unused" port fields and this patch breaks that code :( So we need to fix that driver up before this can be accepted. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steve Sakoman <steve@sakoman.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ad8c0eaa |
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26-Sep-2018 |
Nicolas Ferre <nicolas.ferre@microchip.com> |
tty/serial_core: add ISO7816 infrastructure Add the ISO7816 ioctl and associated accessors and data structure. Drivers can then use this common implementation to handle ISO7816 (smart cards). Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> [ludovic.desroches@microchip.com: squash and rebase, removal of gpios, checkpatch fixes] Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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c550f01c |
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20-Sep-2018 |
Steve Sakoman <steve@sakoman.com> |
serial:serial_core: Allow use of CTS for PPS line discipline Add a "pps_4wire" file to serial ports in sysfs in case the kernel is configured with CONFIG_PPS_CLIENT_LDISC. Writing 1 to the file enables the use of CTS instead of DCD for PPS signal input. This is necessary in case a serial port is not completely wired. Though this affects PPS processing the patch is against the serial core as the source of the serial port PPS event dispatching has to be modified. Furthermore it should be possible to modify the source of serial port PPS event dispatching before changing the line discipline. Signed-off-by: Andreas Steinmetz <ast@domdv.de> Signed-off-by: Steve Sakoman <steve@sakoman.com> Tested-by: Steve Sakoman <steve@sakoman.com> Tested-by: Eric Gallimore <egallimore@ucsd.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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a5ba1d95 |
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06-Jul-2018 |
Tycho Andersen <tycho@tycho.pizza> |
uart: fix race between uart_put_char() and uart_shutdown() We have reports of the following crash: PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0" #0 [ffff88085c6db710] machine_kexec at ffffffff81046239 #1 [ffff88085c6db760] crash_kexec at ffffffff810fc248 #2 [ffff88085c6db830] oops_end at ffffffff81008ae7 #3 [ffff88085c6db860] no_context at ffffffff81050b8f #4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75 #5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83 #6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e #7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c #8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122 [exception RIP: uart_put_char+149] RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006 RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081 RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120 RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320 R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000 R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544 #10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c #11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b #12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2 #13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b #14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a #15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016 #16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194 #17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a #18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2 #19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d #20 [ffff88085c6dbeb0] kthread at ffffffff81096384 #21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f after slogging through some dissasembly: ffffffff814b6720 <uart_put_char>: ffffffff814b6720: 55 push %rbp ffffffff814b6721: 48 89 e5 mov %rsp,%rbp ffffffff814b6724: 48 83 ec 20 sub $0x20,%rsp ffffffff814b6728: 48 89 1c 24 mov %rbx,(%rsp) ffffffff814b672c: 4c 89 64 24 08 mov %r12,0x8(%rsp) ffffffff814b6731: 4c 89 6c 24 10 mov %r13,0x10(%rsp) ffffffff814b6736: 4c 89 74 24 18 mov %r14,0x18(%rsp) ffffffff814b673b: e8 b0 8e 58 00 callq ffffffff81a3f5f0 <mcount> ffffffff814b6740: 4c 8b a7 88 02 00 00 mov 0x288(%rdi),%r12 ffffffff814b6747: 45 31 ed xor %r13d,%r13d ffffffff814b674a: 41 89 f6 mov %esi,%r14d ffffffff814b674d: 49 83 bc 24 70 01 00 cmpq $0x0,0x170(%r12) ffffffff814b6754: 00 00 ffffffff814b6756: 49 8b 9c 24 80 01 00 mov 0x180(%r12),%rbx ffffffff814b675d: 00 ffffffff814b675e: 74 2f je ffffffff814b678f <uart_put_char+0x6f> ffffffff814b6760: 48 89 df mov %rbx,%rdi ffffffff814b6763: e8 a8 67 58 00 callq ffffffff81a3cf10 <_raw_spin_lock_irqsave> ffffffff814b6768: 41 8b 8c 24 78 01 00 mov 0x178(%r12),%ecx ffffffff814b676f: 00 ffffffff814b6770: 89 ca mov %ecx,%edx ffffffff814b6772: f7 d2 not %edx ffffffff814b6774: 41 03 94 24 7c 01 00 add 0x17c(%r12),%edx ffffffff814b677b: 00 ffffffff814b677c: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b6782: 75 23 jne ffffffff814b67a7 <uart_put_char+0x87> ffffffff814b6784: 48 89 c6 mov %rax,%rsi ffffffff814b6787: 48 89 df mov %rbx,%rdi ffffffff814b678a: e8 e1 64 58 00 callq ffffffff81a3cc70 <_raw_spin_unlock_irqrestore> ffffffff814b678f: 44 89 e8 mov %r13d,%eax ffffffff814b6792: 48 8b 1c 24 mov (%rsp),%rbx ffffffff814b6796: 4c 8b 64 24 08 mov 0x8(%rsp),%r12 ffffffff814b679b: 4c 8b 6c 24 10 mov 0x10(%rsp),%r13 ffffffff814b67a0: 4c 8b 74 24 18 mov 0x18(%rsp),%r14 ffffffff814b67a5: c9 leaveq ffffffff814b67a6: c3 retq ffffffff814b67a7: 49 8b 94 24 70 01 00 mov 0x170(%r12),%rdx ffffffff814b67ae: 00 ffffffff814b67af: 48 63 c9 movslq %ecx,%rcx ffffffff814b67b2: 41 b5 01 mov $0x1,%r13b ffffffff814b67b5: 44 88 34 0a mov %r14b,(%rdx,%rcx,1) ffffffff814b67b9: 41 8b 94 24 78 01 00 mov 0x178(%r12),%edx ffffffff814b67c0: 00 ffffffff814b67c1: 83 c2 01 add $0x1,%edx ffffffff814b67c4: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b67ca: 41 89 94 24 78 01 00 mov %edx,0x178(%r12) ffffffff814b67d1: 00 ffffffff814b67d2: eb b0 jmp ffffffff814b6784 <uart_put_char+0x64> ffffffff814b67d4: 66 66 66 2e 0f 1f 84 data32 data32 nopw %cs:0x0(%rax,%rax,1) ffffffff814b67db: 00 00 00 00 00 for our build, this is crashing at: circ->buf[circ->head] = c; Looking in uart_port_startup(), it seems that circ->buf (state->xmit.buf) protected by the "per-port mutex", which based on uart_port_check() is state->port.mutex. Indeed, the lock acquired in uart_put_char() is uport->lock, i.e. not the same lock. Anyway, since the lock is not acquired, if uart_shutdown() is called, the last chunk of that function may release state->xmit.buf before its assigned to null, and cause the race above. To fix it, let's lock uport->lock when allocating/deallocating state->xmit.buf in addition to the per-port mutex. v2: switch to locking uport->lock on allocation/deallocation instead of locking the per-port mutex in uart_put_char. Note that since uport->lock is a spin lock, we have to switch the allocation to GFP_ATOMIC. v3: move the allocation outside the lock, so we can switch back to GFP_KERNEL Signed-off-by: Tycho Andersen <tycho@tycho.ws> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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6396bb22 |
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12-Jun-2018 |
Kees Cook <keescook@chromium.org> |
treewide: kzalloc() -> kcalloc() The kzalloc() function has a 2-factor argument form, kcalloc(). This patch replaces cases of: kzalloc(a * b, gfp) with: kcalloc(a * b, gfp) as well as handling cases of: kzalloc(a * b * c, gfp) with: kzalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kzalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kzalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(char) * COUNT + COUNT , ...) | kzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kzalloc + kcalloc ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kzalloc(C1 * C2 * C3, ...) | kzalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kzalloc(sizeof(THING) * C2, ...) | kzalloc(sizeof(TYPE) * C2, ...) | kzalloc(C1 * C2 * C3, ...) | kzalloc(C1 * C2, ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - (E1) * E2 + E1, E2 , ...) | - kzalloc + kcalloc ( - (E1) * (E2) + E1, E2 , ...) | - kzalloc + kcalloc ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
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8a8dcabf |
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13-Apr-2018 |
Christoph Hellwig <hch@lst.de> |
tty: replace ->proc_fops with ->proc_show Just set up the show callback in the tty_operations, and use proc_create_single_data to create the file without additional boilerplace code. Signed-off-by: Christoph Hellwig <hch@lst.de>
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c5f78b1f |
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26-Mar-2018 |
Jeremy Kerr <jk@ozlabs.org> |
serial: Introduce UPSTAT_SYNC_FIFO for synchronised FIFOs This change adds a flag to indicate that a UART is has an external means of synchronising its FIFO, without needing CTSRTS or XON/XOFF. This allows us to use the throttle/unthrottle callbacks, without having to claim other methods of flow control. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Tested-by: Eddie James <eajames@linux.vnet.ibm.com> Tested-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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4f794097 |
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20-Mar-2018 |
Jeremy Kerr <jk@ozlabs.org> |
serial: expose buf_overrun count through proc interface The buf_overrun count is only every written, and not exposed to userspace anywhere. This means that dropped characters due to flip buffer overruns are never visible to userspace. The /proc/tty/driver/serial file exports a bunch of metrics (including hardware overruns) already, so add the buf_overrun (as "bo:") to this file. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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71456906 |
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02-Feb-2018 |
Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
serial: core: mark port as initialized in autoconfig This is a followup on 44117a1d1732 ("serial: core: mark port as initialized after successful IRQ change"). Nikola has been using autoconfig via setserial and reported a crash similar to what I fixed in the earlier mentioned commit. Here I do the same fixup for the autoconfig. I wasn't sure that this is the right approach. Nikola confirmed that it fixes his crash. Fixes: b3b576461864 ("tty: serial_core: convert uart_open to use tty_port_open") Link: http://lkml.kernel.org/r/20180131072000.GD1853@localhost.localdomain Reported-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz> Tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz> Acked-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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44117a1d |
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11-Jan-2018 |
Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
serial: core: mark port as initialized after successful IRQ change setserial changes the IRQ via uart_set_info(). It invokes uart_shutdown() which free the current used IRQ and clear TTY_PORT_INITIALIZED. It will then update the IRQ number and invoke uart_startup() before returning to the caller leaving TTY_PORT_INITIALIZED cleared. The next open will crash with | list_add double add: new=ffffffff839fcc98, prev=ffffffff839fcc98, next=ffffffff839fcc98. since the close from the IOCTL won't free the IRQ (and clean the list) due to the TTY_PORT_INITIALIZED check in uart_shutdown(). There is same pattern in uart_do_autoconfig() and I *think* it also needs to set TTY_PORT_INITIALIZED there. Is there a reason why uart_startup() does not set the flag by itself after the IRQ has been acquired (since it is cleared in uart_shutdown)? Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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0f646b63 |
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28-Dec-2017 |
Paul Cercueil <paul@crapouillou.net> |
serial: core: Make uart_parse_options take const char* argument The pointed string is never modified from within uart_parse_options, so it should be marked as const in the function prototype. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f1e5b618 |
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24-Nov-2017 |
Lukas Wunner <lukas@wunner.de> |
serial: core: Support common rs485 binding for RTS polarity When a driver invokes the uart_get_rs485_mode() helper, set the RTS polarity to active high by default unless the newly introduced "rs485-rts-active-low" property was specified. imx contains a line to set the default RTS polarity to active high, it is now superfluous and hence deleted. omap-serial historically defaults to active low and supports an "rs485-rts-active-high" property to inverse the polarity. Retain that behavior for compatibility. Cc: Mark Jackson <mpfj@newflow.co.uk> Cc: Michał Oleszczyk <oleszczyk.m@gmail.com> Cc: Rafael Gago Castano <rgc@hms.se> Cc: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Lukas Wunner <lukas@wunner.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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743f93f8 |
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24-Nov-2017 |
Lukas Wunner <lukas@wunner.de> |
serial: Make retrieval of rs485 properties platform-agnostic Commit ef838a81dd4d ("serial: Add common rs485 device tree parsing function") consolidated retrieval of rs485 OF properties in a common helper function but did not #ifdef it to CONFIG_OF. The function is therefore included on ACPI platforms as well even though it's not used. On the other hand ACPI platforms with rs485 do exist (e.g. Siemens IOT2040) and they may leverage _DSD to store rs485 properties. Likewise, UART platform devices instantiated from an MFD should be able to specify rs485 properties. In fact, the tty subsystem maintainer had asked for a "generic" function during review of commit ef838a81dd4d: https://marc.info/?l=linux-serial&m=150143441725194&w=4 Thus, instead of constraining the helper to OF platforms, make it platform-agnostic by converting it to device_property_*() functions and renaming it accordingly. In imx.c, move the invocation of uart_get_rs485_mode() from serial_imx_probe_dt() to serial_imx_probe() so that it also gets called for non-OF devices. In omap-serial.c, move its invocation further up within serial_omap_probe_rs485() so that the RTS polarity can be overridden with the driver-specific "rs485-rts-active-high" property once we introduce a generic "rs485-rts-active-low" property. Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Lukas Wunner <lukas@wunner.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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4793f2eb |
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06-Nov-2017 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
tty: serial: Remove redundant license text Now that the SPDX tag is in all tty files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Jiri Slaby <jslaby@suse.com> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
e3b3d0f5 |
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06-Nov-2017 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
tty: add SPDX identifiers to all remaining files in drivers/tty/ It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby <jslaby@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: James Hogan <jhogan@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: "Uwe Kleine-König" <kernel@pengutronix.de> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
9356335f |
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01-Nov-2017 |
Colin Ian King <colin.king@canonical.com> |
serial: core: remove redundant assignment to port The final assignment to port is never read, hence it is redundant and can be removed. Also move the declaration of port to a more local scope. Cleans up clang warning: drivers/tty/serial/serial_core.c:1498:2: warning: Value stored to 'port' is never read Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
ef838a81 |
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13-Sep-2017 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
serial: Add common rs485 device tree parsing function Several drivers have the same device tree parsing code. Create a common helper function for it. This patch bases on work done by Sascha Hauer. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a6845e1e |
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31-Jul-2017 |
Rafael Gago <rafael.gago@gmail.com> |
serial: core: Consider rs485 settings to drive RTS Previously the rs485 settings weren't considered when setting the RTS line, so e.g. closing and reopening a port made serial_core to drive the line as if rs485 was disabled. This patch fixes those issues. Signed-off-by: Rafael Gago Castano <rgc@hms.se> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
aef3ad10 |
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13-Aug-2017 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: remove unneeded irq_wake flag There is no need to duplicate a flag which IRQ core takes care of. Replace custom flag by IRQ core API that retrieves its state. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a17e74c5 |
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25-Jul-2017 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: enforce type for upf_t when copying upf_t is a bitwise defined type and any assignment from different, but compatible, types makes static analyzer unhappy. drivers/tty/serial/serial_core.c:793:29: warning: incorrect type in assignment (different base types) drivers/tty/serial/serial_core.c:793:29: expected int [signed] flags drivers/tty/serial/serial_core.c:793:29: got restricted upf_t [usertype] flags drivers/tty/serial/serial_core.c:867:19: warning: incorrect type in assignment (different base types) drivers/tty/serial/serial_core.c:867:19: expected restricted upf_t [usertype] new_flags drivers/tty/serial/serial_core.c:867:19: got int [signed] flags Enforce corresponding types when upf_t being assigned. Note, we need __force attribute due to the scope of variable. It's being used in user space with plain old type while kernel uses bitwise one. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
dc2f7271 |
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05-Jun-2017 |
Johan Hovold <johan@kernel.org> |
serial: rate limit custom-speed deprecation notice Contrary to what a comment claimed, the ASYNC_SPD flags and custom divisor can be set by a non-privileged user so rate limit the deprecation notice as was intended. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
da4c2799 |
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18-May-2017 |
Johan Hovold <johan@kernel.org> |
serial: enable serdev support Enable serdev support by using the new device-registration helpers. Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
88e2582e |
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10-May-2017 |
Lucas Stach <l.stach@pengutronix.de> |
serial: core: fix crash in uart_suspend_port With serdev we might end up with serial ports that have no cdev exported to userspace, as they are used as the bus interface to other devices. In that case serial_match_port() won't be able to find a matching tty_dev. Skip the irq wakeup enabling in that case, as serdev will make sure to keep the port active, as long as there are devices depending on it. Fixes: 8ee3fde04758 (tty_port: register tty ports with serdev bus) Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
cade3580 |
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31-Mar-2017 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: Re-use struct uart_port {name} field Since we have port name stored in struct uart_port, we better to use that one instead of open coding. This will make it one place source for easier maintenance or modifications. While here, replace printk(KERN_INFO ) by pr_info(). It seems last printk() call in serial_core.c. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
f7048b15 |
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23-Mar-2017 |
Vignesh R <vigneshr@ti.com> |
tty: serial_core: Add name field to uart_port struct Introduce a field to store name of uart_port that can be used to easily identify UART port instances on a system that has more than one UART instance. The name is of the form ttyXN(eg. ttyS0, ttyAMA0,..) where N is number that particular UART instance. This field will be useful when printing debug info for a particular port or in register IRQs with unique IRQ name. Port name is populated during uart_add_one_port(). Signed-off-by: Vignesh R <vigneshr@ti.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
22077b09 |
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14-Mar-2017 |
Jiri Slaby <jirislaby@kernel.org> |
tty: serial_core, remove state checks in uart_poll* Coverity complains about uart_state checks in polling functions. And it is indeed correct. We do something like this: struct uart_state *state = drv->state + line; if (!state) return; Adding 'line' to drv->state would move the potential NULL pointer to something near NULL and the check is useless. Even if we checked pure drv->state, nothing guarantees it is not freed and NULLed after the check. So if the only user of this interface (kgdboc) needs to assure something, this is neither the correct thing, nor place to do so. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: linux-serial@vger.kernel.org Cc: Jason Wessel <jason.wessel@windriver.com> Cc: kgdb-bugreport@lists.sourceforge.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
174cd4b1 |
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02-Feb-2017 |
Ingo Molnar <mingo@kernel.org> |
sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
7c0f6ba6 |
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24-Dec-2016 |
Linus Torvalds <torvalds@linux-foundation.org> |
Replace <asm/uaccess.h> with <linux/uaccess.h> globally This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
ef510bea |
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24-Nov-2016 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: don't check port twice in a row There is no need to check port for NULL in uart_port_deref() since we call it only when port is defined. There are few places that violate this. Fix them here as well. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d0f4bce2 |
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28-Oct-2016 |
Rob Herring <robh@kernel.org> |
tty: serial_core: fix NULL struct tty pointer access in uart_write_wakeup Since commit 761ed4a94582ab29 ("tty: serial_core: convert uart_close to use tty_port_close"), the serial console is broken on various systems and typing "reboot" splats the following on the serial console: INIT: Sending p[ 427.863916] BUG: unable to handle kernel NULL pointer dereference at 00000000000001e0 [ 427.885156] IP: [] tty_wakeup+0xc/0x70 [ 427.898337] PGD 0 [ 427.902051] [ 427.907498] Oops: 0000 [#1] PREEMPT SMP [ 427.917635] Modules linked in: nfsv3 nfs_acl nfs fscache lockd sunrpc grace edd af_packet cpufreq_conservative cpufreq_userspace cpufreq_powersave fuse loop md_mod dm_mod joydev hid_generic usbhid ipmi_ssif ohci_pci ohci_hcd ehci_pci ehci_hcd e1000e ptp firewire_ohci edac_core pps_core tpm_infineon sp5100_tco firewire_core acpi_cpufreq serio_raw pcspkr fjes usbcore shpchp edac_mce_amd tpm_tis ipmi_si tpm_tis_core i2c_piix4 k10temp sg ipmi_msghandler tpm sr_mod button cdrom kvm_amd kvm irqbypass crc_itu_t ast ttm drm_kms_helper drm fb_sys_fops sysimgblt sysfillrect syscopyarea i2c_algo_bit scsi_dh_rdac scsi_dh_alua scsi_dh_emc scsi_dh_hp_sw ata_generic pata_atiixp [ 428.054179] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.0-rc1-1.g73e3f23-default #1 [ 428.072868] Hardware name: System manufacturer System Product Name/KGP(M)E-D16, BIOS 0902 12/03/2010 [ 428.094755] task: ffffffffa2c0d500 task.stack: ffffffffa2c00000 [ 428.109717] RIP: 0010:[] [] tty_wakeup+0xc/0x70 [ 428.128407] RSP: 0018:ffff9a1a5fc03df8 EFLAGS: 00010086 [ 428.142184] RAX: ffff9a1857258000 RBX: ffffffffa3050ea0 RCX: 0000000000000000 [ 428.159649] RDX: 000000000000001b RSI: 0000000000000000 RDI: 0000000000000000 [ 428.177109] RBP: ffff9a1a5fc03e08 R08: 0000000000000000 R09: 0000000000000000 [ 428.194547] R10: 0000000000021c77 R11: 0000000000000000 R12: ffff9a1857258000 [ 428.212002] R13: 0000000000000000 R14: 0000000000000020 R15: 0000000000000020 [ 428.229481] FS: 0000000000000000(0000) GS:ffff9a1a5fc00000(0000) knlGS:0000000000000000 [ 428.248938] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 428.263726] CR2: 00000000000001e0 CR3: 0000000390c06000 CR4: 00000000000006f0 [ 428.281331] Stack: [ 428.288696] ffffffffa3050ea0 ffff9a1857258000 ffff9a1a5fc03e18 ffffffffa24e0ab1 [ 428.307064] ffff9a1a5fc03e40 ffffffffa24e8865 ffffffffa3050ea0 00000000000000c2 [ 428.325456] 0000000000000046 ffff9a1a5fc03e78 ffffffffa24e8a5f ffffffffa3050ea0 [ 428.343905] Call Trace: [ 428.352319] [ 428.356216] [] uart_write_wakeup+0x21/0x30 The problem is for console ports, the serial port is not shutdown and interrupts may fire after the struct tty is gone. Simply calling the tty_port helper tty_port_tty_wakeup instead of tty_wakeup directly will ensure there is a valid struct tty. Fixes: 761ed4a94582ab29 ("tty: serial_core: convert uart_close to use tty_port_close") Reported-by: Borislav Petkov <bp@alien8.de> Reported-by: Mike Galbraith <mgalbraith@suse.de> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-serial@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
4dda864d |
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28-Oct-2016 |
Geert Uytterhoeven <geert+renesas@glider.be> |
tty: serial_core: Fix serial console crash on port shutdown The port->console flag is always false, as uart_console() is called before the serial console has been registered. Hence for a serial port used as the console, uart_tty_port_shutdown() will still be called when userspace closes the port, powering it down. This may lead to a system lock up when the serial console driver writes to the serial port's registers. To fix this, move the setting of port->console after the call to uart_configure_port(), which registers the serial console. Fixes: 761ed4a94582ab29 ("tty: serial_core: convert uart_close to use tty_port_close") Reported-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Rob Herring <robh@kernel.org> Tested-by: Mugunthan V N <mugunthanvnm@ti.com> Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> [robh: rebased on tty-linus] Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
be2c92b8 |
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24-Oct-2016 |
Rob Herring <robh@kernel.org> |
serial: core: fix console problems on uart_close Commit 761ed4a94582 ('tty: serial_core: convert uart_close to use tty_port_close') started setting the ttyport console flag for serial drivers. This is causing crashes, hangs, or garbage output on several platforms because the serial shutdown is skipped and IRQs are left enabled. Partially revert commit 761ed4a94582 and drop reporting UART tty_ports as a console leaving the console handling to the serial_core as it was before. Fixes: 761ed4a94582ab29 ("tty: serial_core: convert uart_close to use tty_port_close") Reported-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com> Reported-by: Mugunthan V N <mugunthanvnm@ti.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Alan Cox <alan@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-serial@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a5a2b130 |
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12-Sep-2016 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
serial: core: fix potential NULL pointer dereference The commit 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") refactored uart_close() to use tty_port_close(). At the same time it introduced a potential NULL pointer dereference. Rearrange the code to avoid kernel crash. Fixes: 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") Cc: Rob Herring <robh@kernel.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
8b2303de |
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12-Sep-2016 |
Alexander Sverdlin <alexander.sverdlin@nokia.com> |
serial: core: Fix handling of options after MMIO address Guenter Roeck reported a regression caused by commit "serial: earlycon: Extend earlycon command line option to support 64-bit addresses": console= and earlycon= options have the following format: ...,<addr>,<options> Historically used here simple_strtoul() had no problems with comma, but the new and recommended kstrtoull() requires null-terminated string and returns -EINVAL in case there are "options" at the end. There is no recommended to use function currently that will support it, so stick to obsolete simple_strtoull() variant. Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
46e36683 |
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02-Sep-2016 |
Alexander Sverdlin <alexander.sverdlin@nokia.com> |
serial: earlycon: Extend earlycon command line option to support 64-bit addresses earlycon implementation used "unsigned long" internally, but there are systems (ARM with LPAE) where sizeof(unsigned long) == 4 and uart is mapped beyond 4GiB address range. Switch to resource_size_t internally and replace obsoleted simple_strtoul() with kstrtoull(). Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
761ed4a9 |
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22-Aug-2016 |
Rob Herring <robh@kernel.org> |
tty: serial_core: convert uart_close to use tty_port_close tty_port_close handles much of the common parts of tty close. Convert uart_close to use it and move the serial_core specific parts into tty_port.shutdown function. This will be needed to use tty_port functions directly from in kernel clients. This change causes ops->stop_rx() to be called after uart_wait_until_sent() is called which I think should be fine. Otherwise, the sequence of the close should be the same. Cc: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
b3b57646 |
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22-Aug-2016 |
Rob Herring <robh@kernel.org> |
tty: serial_core: convert uart_open to use tty_port_open tty_port_open handles much of the common parts of tty opening. Convert uart_open to use it and move the serial_core specific parts into tty_port.activate function. This will be needed to use tty_port functions directly from in kernel clients. The tricky part is uart_port_startup can return positive values to allow setserial to configure the port. We now return the positive value to tty_port_open so that the tty is not marked as initialized and then set the return value in uart_open to 0. Cc: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a7cfaf16 |
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19-May-2016 |
Fabio Estevam <fabio.estevam@nxp.com> |
serial: serial_core: Perform NULL checks for release/request_port ops Doing the following UART bind/unbind sequence on a i.mx platform causes a kernel crash due to NULL pointer dereference: echo 21f4000.serial > /sys/bus/platform/drivers/imx-uart/bind echo 21f4000.serial > /sys/bus/platform/drivers/imx-uart/unbind Fix this problem by adding NULL checks prior to calling release/request_port ops. Reported-by: Fugang Duan <fugang.duan@nxp.com> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Tested-by: Fugang Duan <fugang.duan@nxp.com> Acked-by: Fugang Duan <fugang.duan@nxp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
7da4b8b7 |
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03-May-2016 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Fix port mutex assert if lockdep disabled commit 4047b37122d1 ("serial: core: Prevent unsafe uart port access, part 1") added lockdep assertion for port mutex but fails to check if debug_locks has disabled lockdep (so lock state is no longer reliable). Use lockdep_assert_held() instead, which properly checks lockdep state as well. Reported-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
af224ca2 |
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09-Apr-2016 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Prevent unsafe uart port access, part 3 For tty operations which may expect uart port to have been removed but still have other necessary work to accomplish, check for NULL uart port; specifically uart_close(), uart_hangup() and sub-functions (uart_shutdown() and uart_port_shutdown()). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
9ed19428 |
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09-Apr-2016 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Prevent unsafe uart port access, part 2 For serial core operations not already excluded by holding port->mutex, use reference counting to protect deferencing the state->uart_port. Introduce helper functions, uart_port_ref() and uart_port_deref(), to wrap uart_port access, and helper macros, uart_port_lock() and uart_port_unlock(), to wrap combination uart_port access with uart port lock sections. Port removal in uart_remove_one_port() waits for reference count to drop to zero before detaching the uart port from struct uart_state. For functions only reading the tx circular buffer indexes (where the uart port lock is claimed to prevent concurrent users), a NULL uart port is simply ignored and the operation completes normally. For functions change the tx circular buffer indexes (where the uart port lock is claimed to prevent concurrent users), the operation is aborted if the uart port is NULL (ie., has been detached). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
4047b371 |
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09-Apr-2016 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Prevent unsafe uart port access, part 1 uart_remove_one_port() may race with every serial core operation requiring a valid dereference of state->uart_port. In particular, uart_remove_one_port() may unlink the uart port concurrently with any serial core operation that may dereference same. Ensure safe dereference for those operations that already claim the port->mutex, and extend that guarantee for trivial cases, such as the ioctl handlers. Introduce the uart_port_check() helper which asserts port->mutex is held (only when lockdep is on). For ioctls, return -EIO as if the port has been hung up (since it has). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
49c02304 |
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09-Apr-2016 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Expand port mutex section in uart_poll_init() Prepare uart_poll_init() to safely dereference uart port; expand the port mutex section to guarantee uart port remains valid until uart_poll_init() completes. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d41861ca |
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09-Apr-2016 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Replace ASYNC_INITIALIZED bit and update atomically Replace ASYNC_INITIALIZED bit in the tty_port::flags field with TTY_PORT_INITIALIZED bit in the tty_port::iflags field. Introduce helpers tty_port_set_initialized() and tty_port_initialized() to abstract atomic bit ops. Note: the transforms for test_and_set_bit() and test_and_clear_bit() are unnecessary as the state transitions are already mutually exclusive; the tty lock prevents concurrent open/close/hangup. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
80f02d54 |
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09-Apr-2016 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Replace ASYNC_SUSPENDED bit and update atomically Replace ASYNC_SUSPENDED bit in the tty_port::flags field with TTY_PORT_SUSPENDED bit in the tty_port::iflags field. Introduce helpers tty_port_set_suspended() and tty_port_suspended() to abstract atomic bit ops. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
807c8d81 |
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09-Apr-2016 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Replace ASYNC_NORMAL_ACTIVE bit and update atomically Replace ASYNC_NORMAL_ACTIVE bit in the tty_port::flags field with TTY_PORT_ACTIVE bit in the tty_port::iflags field. Introduce helpers tty_port_set_active() and tty_port_active() to abstract atomic bit ops. Extract state changes from port lock sections, as this usage is broken and confused; the state transitions are protected by the tty lock (which mutually excludes parallel open/close/hangup), and no user tests the active state while holding the port lock. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
97ef38b8 |
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09-Apr-2016 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Replace TTY_THROTTLED bit tests with tty_throttled() Abstract TTY_THROTTLED bit tests with tty_throttled(). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
18900ca6 |
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09-Apr-2016 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Replace TTY_IO_ERROR bit tests with tty_io_error() Abstract TTY_IO_ERROR status test treewide with tty_io_error(). NB: tty->flags uses atomic bit ops; replace non-atomic bit test with test_bit(). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
ba47f97a |
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04-Jan-2016 |
Jeffy Chen <jeffy.chen@rock-chips.com> |
serial: core: remove baud_rates when serial console setup Currently, when tring to set up a serial console with a higher baud rate, it would fallback to 921600. Tested-by: Jianqun Xu <jay.xu@rock-chips.com> Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
afc5ab09 |
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10-Jan-2016 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Remove ASYNC_CLOSING The tty core no longer provides nor uses ASYNC_CLOSING; remove from tty_port_close_start() and tty_port_close_end() as well as tty drivers which open-code these state changes. Unfortunately, even though the bit is masked from userspace, its inclusion in a uapi header precludes removing the macro. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: linux-cris-kernel@axis.com Cc: Samuel Ortiz <samuel@sortiz.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
b4749b97 |
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10-Jan-2016 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Perform RTS signalling before soft flow ctrl When throttling, time is of the essence; try RTS signalling before soft flow control, which will take longer. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
968af298 |
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10-Jan-2016 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Unfold < 80 char lines Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
5e388027 |
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10-Jan-2016 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Remove cast from void ptr in uart_open() void * promotes to any pointer type; remove type cast. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
f9d1083d |
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10-Jan-2016 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Cleanup uart_open() exit If aborting uart_open() unsuccessfully, retval is non-zero, so the existing fall-through exit is equivalent. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
39b3d892 |
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10-Jan-2016 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Use tty->index for port # in debug messages The uart port may have already been removed by uart_remove_one_port(); use equivalent tty->index (which is always valid in these contexts) instead. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
3abe8c76 |
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10-Jan-2016 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Fold do_uart_get_info() into caller do_uart_get_info() has a single caller: uart_get_info(). Manually inline do_uart_get_info(). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
f5291ecc |
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10-Jan-2016 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Fold __uart_put_char() into caller uart_put_char() is the required interface; manually inline __uart_put_char(). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
9db276f8 |
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10-Jan-2016 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Use termios c_*flag macros Expressions of the form "tty->termios.c_*flag & FLAG" are more clearly expressed with the termios flags macros, I_FLAG(), C_FLAG(), O_FLAG(), and L_FLAG(). Convert treewide. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
bd94c407 |
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27-Oct-2015 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
serial: support 16-bit register interface for console Currently, 8-bit (MMIO) and 32-bit (MMIO32) register interfaces are supported for the 8250 console, but the 16-bit (MMIO16) is not. The 8250 UART device on my board is connected to a 16-bit bus and my main motivation is to use earlycon with it. (Refer to arch/arm/boot/dts/uniphier-support-card.dtsi) Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
f4581cab |
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27-Oct-2015 |
Denys Vlasenko <dvlasenk@redhat.com> |
serial_core: Deinline uart_update_mctrl, save 304 bytes This function compiles to 92 bytes of machine code. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> CC: Jiri Slaby <jslaby@suse.com> CC: linux-serial@vger.kernel.org Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
cc2aaabf |
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10-Oct-2015 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Remove tty_port::close_wait With the removal of tty_wait_until_sent_from_close(), tty drivers no longer wait during open for parallel closes to complete (instead, the tty core waits before calling the driver open() method). Thus, the close_wait waitqueue is no longer used for waiting. Remove struct tty_port::close_wait. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d215d809 |
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22-Sep-2015 |
Max Filippov <jcmvbkbc@gmail.com> |
serial_core: support native endianness There are three natural ways in which devices may be wired to the system: little endian (device receives correctly ordered bits of a word written by little-endian CPU to its register, but big-endian CPU needs to swap bytes of a word before writing it), big endian (same, but with big-endian CPU in more favourable position) and native endian (CPU of either endianness may do word-sized I/O without need for byteswapping). Adding an option for native endianness allows using single kernel command line for boards with native-endian serial ports on bi-endian architectures. This goes in parallel with 'native-endian' DTS attribute. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
9e31364f |
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31-Jul-2015 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Remove tty port activate() and shutdown() methods serial core does not use tty_port_open() or tty_port_close(); serial core defines and extends it's own tty open() and close() methods (uart_open() and uart_close(), respectively). Remove the tty_port activate() and shutdown() initializations, and the uart_port_activate() function, which is never called. NB: uart_port_shutdown() is used by uart_close() => uart_shutdown() call chain (but not via the tty_port methods). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
6fb98fb3 |
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31-Jul-2015 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Use proper spinlock flavor in uart_close() uart_close() runs in non-atomic context only; use spin_lock/unlock_irq instead of saving the interrupt state (which == on). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
e144c58c |
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12-Jul-2015 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Fix crashes while echoing when closing While closing, new rx data may be received after the input buffers have been flushed but before stop_rx() halts receiving [1]. The new data might not be processed by flush_to_ldisc() until after uart_shutdown() and normal input processing is re-enabled (ie., tty->closing = 0). The race is outlined below: CPU 0 | CPU 1 | uart_close() | tty_port_close_start() | tty->closing = 1 | tty_ldisc_flush() | | => IRQ | while (LSR & data ready) | uart_insert_char() | tty_flip_buffer_push() | <= EOI stop_rx() | . uart_shutdown() | . free xmit.buf | . tty_port_tty_set(NULL) | . tty->closing = 0 | . | flush_to_ldisc() | n_tty_receive_buf_common() | __receive_buf() | ... | commit_echoes() | uart_flush_chars() | __uart_start() | ** OOPS on port.tty deref ** tty_ldisc_flush() | Input processing must be prevented from echoing (tty->closing = 1) until _after_ the input buffers have been flushed again at the end of uart_close(). [1] In fact, some input may actually be buffered _after_ stop_rx() since the rx interrupt may have already triggered but not yet been handled when stop_rx() disables rx interrupts. Fixes: 2e758910832d ("serial: core: Flush ldisc after dropping port mutex in uart_close()") Reported-by: Robert Elliott <elliott@hp.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
f10a2233 |
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08-Jun-2015 |
Joakim Nordell <joakim.nordell@intel.com> |
serial: core: cleanup in uart_get_baud_rate() Align with coding guidelines: Replaced a chain of "else if" by a switch case. Signed-off-by: Joakim Nordell <joakim.nordell@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
6e63be3f |
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24-May-2015 |
Noam Camus <noamc@ezchip.com> |
serial: earlycon: Add support for big-endian MMIO accesses Support command line parameters of the form: earlycon=<name>,io|mmio|mmio32|mmio32be,<addr>,<options> This commit seem to be needed even after commit: serial: 8250: Add support for big-endian MMIO accesses c627f2ceb692e8a9358b64ac2d139314e7bb0d17 Signed-off-by: Noam Camus <noamc@ezchip.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
429b4749 |
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31-Mar-2015 |
Rasmus Villemoes <linux@rasmusvillemoes.dk> |
tty: remove buf parameter from tty_name() tty_name no longer uses the buf parameter, so remove it along with all the 64 byte stack buffers that used to be passed in. Mostly generated by the coccinelle script @depends on patch@ identifier buf; constant C; expression tty; @@ - char buf[C]; <+... - tty_name(tty, buf) + tty_name(tty) ...+> allmodconfig compiles, so I'm fairly confident the stack buffers weren't used for other purposes as well. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
10afbe34 |
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11-Apr-2015 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Fix kernel-doc build warnings Fix uart_console_write() kernel-doc build warnings. Warning(drivers/tty/serial/serial_core.c:1778): No description found for parameter 'putchar' Warning(drivers/tty/serial/serial_core.c:1778): Excess function parameter 'write' description in 'uart_console_write' Fixes: 1cfe42b7fd29 ("serial: core: Fix kernel doc for uart_console_write()") Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
1cfe42b7 |
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09-Mar-2015 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Fix kernel doc for uart_console_write() '/**' is required to start a kernel-doc comment block. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
959801fe |
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24-Feb-2015 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Add minor field to uart_port UART drivers that share ttyS namespace cannot trivially compute the ttyS index from the port->line value since the minor_start may be offset from minor 64. Further, to do so requires a pointer to the uart driver since there is no back pointer from uart_port to uart_driver. Rather than have UART drivers computing the minor value by themselves, encapsulate within the serial core at port registration time. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
73abaf87 |
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01-Mar-2015 |
Peter Hurley <peter@hurleysoftware.com> |
serial: earlycon: Refactor parse_options into serial core Prepare to support console-defined matching; refactor the command line parameter string processing from parse_options() into a new core function, uart_parse_earlycon(), which decodes command line parameters of the form: earlycon=<name>,io|mmio|mmio32,<addr>,<options> console=<name>,io|mmio|mmio32,<addr>,<options> earlycon=<name>,0x<addr>,<options> console=<name>,0x<addr>,<options> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
97f9f707 |
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20-Feb-2015 |
Fabian Frederick <fabf@skynet.be> |
serial: core: replace current->state by __set_current_state() Use helper functions to access current->state. Direct assignments are prone to races and therefore buggy. Thanks to Peter Zijlstra for the exact definition of the problem. Suggested-By: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
391f93f2 |
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25-Jan-2015 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Rework hw-assisted flow control support hw-assisted flow control support was added to the serial core in v3.8 with commits, dba05832cbe4f ("SERIAL: core: add hardware assisted h/w flow control support") 2cbacafd7af0f ("SERIAL: core: add hardware assisted s/w flow control support") 9aba8d5b01119 ("SERIAL: core: add throttle/unthrottle callbacks for hardware assisted flow control") Since then, additional requirements for serial core support have arisen. Specifically, 1. Separate tx and rx flow control settings for UARTs which only support tx flow control (ie., autoCTS). 2. Disable sw-assisted CTS flow control in autoCTS mode 3. Support for RTS flow control by serial core and userspace in autoRTS mode Distinguish mode from capability; introduce UPSTAT_AUTORTS, UPSTAT_AUTOCTS and UPSTAT_AUTOXOFF which, when set by the uart driver, enable serial core support for hw-assisted rx, hw-assisted tx and hw-assisted in-band/IXOFF rx flow control, respectively. [Note: hw-assisted in-band/IXON tx flow control does not require serial core support/intervention and can be enabled by the uart driver when required.] These modes must be set/reset in the driver's set_termios() method, based on termios settings, and thus can be safely queried in any context in which one of the port lock, port mutex or termios rwsem are held. Set these modes in the 2 in-tree drivers, omap-serial and 8250_omap, which currently use UPF_HARD_FLOW/UPF_SOFT_FLOW support. Retain UPF_HARD_FLOW and UPF_SOFT_FLOW as capabilities; re-define UPF_HARD_FLOW as both UPF_AUTO_RTS and UPF_AUTO_CTS to allow for distinct and separate rx and tx flow control capabilities. Disable sw-assisted CTS flow control when UPSTAT_AUTOCTS is enabled. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
b164c972 |
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21-Jan-2015 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Simplify console suspend logic in uart_suspend_port() When the uart port being suspended is a console and consoles are not suspending (kernel command line contains no_console_suspend), then no action is performed for that port, and the function can return early. If the function has not returned early, then one of the conditions is not true, so the expression (console_suspend_enabled || !uart_console(uport)) must be true and can be eliminated. Similarly, the expression (console_suspend_enabled && uart_console(uport)) simplifies to just uart_console(uport). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
68ed7e1c |
|
02-Jan-2015 |
James Bottomley <JBottomley@Parallels.com> |
serial: fix parisc boot hang This is a partial revert of 2f2dafe (serial: serial_core.c: printk replacement) which gets us booting again. The real problem seems to be the _emit path in early boot. However, until we can root cause it, we need at least to get boot working. Fixes: 2f2dafe77df2c78e189a9fa6b1879dffd06ae5a1 Cc: stable@vger.kernel.org Signed-off-by: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
3ffb1a81 |
|
12-Nov-2014 |
Kevin Cernekee <cernekee@gmail.com> |
serial: core: Add big-endian iotype Since most drivers interpret UPIO_MEM32 to mean "little-endian" and use readl/writel to access the registers, add a parallel UPIO_MEM32BE to request the use of big-endian MMIO accessors (ioread32be/iowrite32be). Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
bd737f87 |
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06-Nov-2014 |
Ricardo Ribalda <ribalda@kernel.org> |
tty/serial_core: Introduce lock mechanism for RS485 Introduce an homogeneous lock system between setting and using the rs485 data of the uart_port. This patch should not be split into multiple ones in order to avoid leaving the tree in an unstable state. Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Suggested-by: Alan Cox <alan@linux.intel.com> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a9c20a9c |
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06-Nov-2014 |
Ricardo Ribalda <ribalda@kernel.org> |
serial_core: Remove call to driver-specific TIO[GS]RS485] Once there is no more handlers for TIOC[GS]RS485 there is no need to call the driver specific ioctl when the generic implementation is missing. Reviewed-by: Alan Cox <alan@linux.intel.com> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a5f276f1 |
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06-Nov-2014 |
Ricardo Ribalda <ribalda@kernel.org> |
serial_core: Handle TIOC[GS]RS485 ioctls. The following drivers: 8250_core, atmel_serial, max310x, mcf, omap-serial and sci16is7xx implement code to handle RS485 ioctls. In order to avoid code duplication, we implement a simple ioctl handler on the serial_core layer. This handler can be used by all the other drivers instead of duplicating code. Until this is the only RS485 ioctl handler, it will try first the rs485_config callback and if it is not present it will call the driver specific ioctl. Reviewed-by: Alan Cox <alan@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
732a84a0 |
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05-Nov-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Pass termios to set_ldisc() notifications UART drivers which enable modem status interrupts when switching to N_PPS line discipline need to determine if modem status interrupts should be disabled when switching from N_PPS. Specifically, the set_ldisc() notification needs to evaluate UART_ENABLE_MS() which requires termios->c_cflag. Convert in-tree UART drivers to new interface. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
db1b9dfc |
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05-Nov-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Claim port mutex for set_ldisc() Three UART drivers (8250, atmel & amba-pl010) enable modem status interrupts if the line discipline is changed to N_PPS. However, the uart port flags may only be safely modified while holding the port mutex. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
91b32f54 |
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16-Oct-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Fix port count when uart_open() errors A port count mismatch occurs if mutex_lock_interruptible() exits uart_open() and the port has already been opened. This may prematurely close a port on an open tty. Since uart_close() is _always_ called if uart_open() fails, the port count must be corrected if errors occur. Always increment the port count in uart_open(), regardless of errors; always decrement the port count in uart_close(). Note that tty_port_close_start() decrements the port count when uart_open() was successful. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
64dbee31 |
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16-Oct-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Remove extra locking in uart_write() uart_start() only claims the port->lock to call __uart_start(), which does the actual processing. Eliminate the extra acquire/release in uart_write(); call __uart_start() directly with port->lock already held. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
2b702b9b |
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16-Oct-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Colocate crucial structure linkage The key function of uart_add_one_port() is to cross-reference the UART driver's port structure with the serial core's state table; keep the assignments together and document this crucial association. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
1f0afd16 |
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16-Oct-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Remove redundant timeout assignments tty_port_init() initializes close_delay and closing_wait to these same values; remove. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
74866e75 |
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16-Oct-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Unwrap >80 char line in uart_close() The wrapped line looks wrong and out-of-place; leave it as >80 char line. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
7c8ab967 |
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16-Oct-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: Fix locking for uart driver set_termios() method The low-level uart driver may modify termios settings to override settings that are not compatible with the uart, such as CRTSCTS. Thus, callers of the low-level uart driver's set_termios() method must hold termios_rwsem write lock to prevent concurrent access to termios, in case such override occurs. The termios_rwsem lock requirement does not extend to console setup (ie., uart_set_options), as console setup cannot race with tty operations. Nor does this lock requirement extend to functions which cannot be concurrent with tty ioctls (ie., uart_port_startup() and uart_resume_port()). Further, always claim the port mutex to protect hardware re-reprogramming in the set_termios() uart driver method. Note this is unnecessary for console initialization in uart_set_options() which cannot be concurrent with other uart operations. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
2e758910 |
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16-Oct-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Flush ldisc after dropping port mutex in uart_close() The tty buffers (and any line discipline buffers) must be flushed after the UART hardware has shutdown; otherwise, a racing open on the same tty may receive data from the previous session, which is a security hazard. However, holding the port mutex while flushing the line discipline buffers creates a lock inversion if the set_termios() handler takes the port mutex (as it does in the followup patch, 'serial: Fix locking for uart driver set_termios method'. Flush the ldisc buffers after dropping the port mutex; the tty lock is still held which prevents a concurrent open() from advancing while flushing. Since no new rx data is possible after uart_shutdown() until a new open reinitializes the port, the later flush has no impact on what data is being discarded. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
479e9b94 |
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16-Oct-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: Refactor uart_flush_buffer() from uart_close() In the context of the final tty & port close, flushing the tx ring buffer after the hardware has already been shutdown and the ring buffer freed is neither required nor desirable. uart_flush_buffer() performs 3 operations: 1. Resets tx ring buffer indices, but the tx ring buffer has already been freed and the indices are reset if the port is re-opened. 2. Calls uart driver's flush_buffer() method 5 in-tree uart drivers define flush_buffer() methods: amba-pl011, atmel-serial, imx, serial-tegra, timbuart These have been refactored into the shutdown() method, if required. 3. Kicks the ldisc for more writing, but this is undesirable. The file handle is being released; any waiting writer will will be kicked out by tty_release() with a warning. Further, the N_TTY ldisc may generate SIGIO for a file handle which is no longer valid. Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
91f189de |
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16-Oct-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: Fix sparse warnings in uart_throttle()/uart_unthrottle() The struct uart_port.flags field is type upf_t, as are the matching bit definitions. Change local mask variable to type upf_t. Fixes sparse warnings: drivers/tty/serial/serial_core.c:620:22: warning: invalid assignment: |= drivers/tty/serial/serial_core.c:620:22: left side has type unsigned int drivers/tty/serial/serial_core.c:620:22: right side has type restricted upf_t drivers/tty/serial/serial_core.c:622:22: warning: invalid assignment: |= drivers/tty/serial/serial_core.c:622:22: left side has type unsigned int drivers/tty/serial/serial_core.c:622:22: right side has type restricted upf_t drivers/tty/serial/serial_core.c:624:17: warning: restricted upf_t degrades to integer drivers/tty/serial/serial_core.c:626:22: warning: invalid assignment: &= drivers/tty/serial/serial_core.c:626:22: left side has type unsigned int drivers/tty/serial/serial_core.c:626:22: right side has type restricted upf_t drivers/tty/serial/serial_core.c:629:20: warning: restricted upf_t degrades to integer drivers/tty/serial/serial_core.c:632:20: warning: restricted upf_t degrades to integer drivers/tty/serial/serial_core.c:643:22: warning: invalid assignment: |= drivers/tty/serial/serial_core.c:643:22: left side has type unsigned int drivers/tty/serial/serial_core.c:643:22: right side has type restricted upf_t drivers/tty/serial/serial_core.c:645:22: warning: invalid assignment: |= drivers/tty/serial/serial_core.c:645:22: left side has type unsigned int drivers/tty/serial/serial_core.c:645:22: right side has type restricted upf_t drivers/tty/serial/serial_core.c:647:17: warning: restricted upf_t degrades to integer drivers/tty/serial/serial_core.c:649:22: warning: invalid assignment: &= drivers/tty/serial/serial_core.c:649:22: left side has type unsigned int drivers/tty/serial/serial_core.c:649:22: right side has type restricted upf_t drivers/tty/serial/serial_core.c:652:20: warning: restricted upf_t degrades to integer drivers/tty/serial/serial_core.c:655:20: warning: restricted upf_t degrades to integer Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d4260b51 |
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16-Oct-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: Fix upstat_t sparse warnings Commit 299245a145b2ad4cfb4c5432eb1264299f55e7e0, serial: core: Privatize modem status enable flags, introduced the upstat_t type and matching bit definitions. The purpose is to produce sparse warnings if the wrong bit definitions are used (by warning of implicit integer conversions). Fix implicit conversion to integer return type from uart_cts_enabled() and uart_dcd_enabled(). Fixes the following sparse warnings: drivers/tty/serial/serial_core.c:63:30: warning: incorrect type in return expression (different base types) drivers/tty/serial/serial_core.c:63:30: expected int drivers/tty/serial/serial_core.c:63:30: got restricted upstat_t include/linux/serial_core.h:364:30: warning: incorrect type in return expression (different base types) include/linux/serial_core.h:364:30: expected bool include/linux/serial_core.h:364:30: got restricted upstat_t include/linux/serial_core.h:364:30: warning: incorrect type in return expression (different base types) include/linux/serial_core.h:364:30: expected bool include/linux/serial_core.h:364:30: got restricted upstat_t Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
547039ec |
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16-Oct-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: Fix divide-by-zero fault in uart_get_divisor() uart_get_baud_rate() will return baud == 0 if the max rate is set to the "magic" 38400 rate and the SPD_* flags are also specified. On the first iteration, if the current baud rate is higher than the max, the baud rate is clamped at the max (which in the degenerate case is 38400). On the second iteration, the now-"magic" 38400 baud rate selects the possibly higher alternate baud rate indicated by the SPD_* flag. Since only two loop iterations are performed, the loop is exited, a kernel WARNING is generated and a baud rate of 0 is returned. Reproducible with: setserial /dev/ttyS0 spd_hi base_baud 38400 Only perform the "magic" 38400 -> SPD_* baud transform on the first loop iteration, which prevents the degenerate case from recognizing the clamped baud rate as the "magic" 38400 value. Reported-by: Robert Święcki <robert@swiecki.net> Cc: <stable@vger.kernel.org> # all Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
69784fa5 |
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02-Oct-2014 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
Revert "serial/core: Initialize the console pm state" This reverts commit a86713b1536c818972675e6dd8c6e738f0379f1d. Kevin Hilman writes: Multiple boot failures on ARM[1] were bisected down to this patch. How was this patch tested, and on which platforms? Also, the changelog states that this should be done only for UART_CAP_SLEEP, but the patch does it for every UART. Greg, I suggest this patch be dropped from tty-next until it has been better described and tested. [1] http://lists.linaro.org/pipermail/kernel-build-reports/2014-October/005550.html Reported-by: Kevin Hilman <khilman@kernel.org> Cc: Sudhir Sreedharan <ssreedharan@mvista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a86713b1 |
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21-Sep-2014 |
Sudhir Sreedharan <ssreedharan@mvista.com> |
serial/core: Initialize the console pm state For console devices having UART_CAP_SLEEP capability, the uart_pm_state has to be initialized to UART_PM_STATE_ON. Otherwise the LCR regiser values are reinitialized when uart_change_pm is called from uart_configure_port. Signed-off-by: Sudhir Sreedharan <ssreedharan@mvista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
938f7e13 |
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10-Sep-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Use spin_lock_irq() in uart_set_termios() uart_set_termios() is called with interrupts enabled; no need to save and restore the interrupt state when taking the uart port lock. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d01f4d18 |
|
10-Sep-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Privatize tty->hw_stopped tty->hw_stopped is not used by the tty core and is thread-unsafe; hw_stopped is a member of a bitfield whose fields are updated non-atomically and no lock is suitable for serializing updates. Replace serial core usage of tty->hw_stopped with uport->hw_stopped. Use int storage which works around Alpha EV4/5 non-atomic byte storage, since uart_port uses different locks to protect certain fields within the structure. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
299245a1 |
|
10-Sep-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Privatize modem status enable flags The serial core uses the tty port flags, ASYNC_CTS_FLOW and ASYNC_CD_CHECK, to track whether CTS and DCD changes should be ignored or handled. However, the tty port flags are not safe for atomic bit operations and no lock provides serialized updates. Introduce the struct uart_port status field to track CTS and DCD enable states, and serialize access with uart port lock. Substitute uart_cts_enabled() helper for tty_port_cts_enabled(). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
4d90bb14 |
|
10-Sep-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Document and assert lock requirements for irq helpers The serial core provides two helper functions, uart_handle_dcd_change() and uart_handle_cts_change(), for UART drivers to use at interrupt time. The serial core expects the UART driver to hold the uart port lock when calling these helpers to prevent state corruption. If lockdep enabled, trigger a warning if the uart port lock is not held when calling these helper functions. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c993257b |
|
02-Sep-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Unwrap tertiary assignment in uart_handle_dcd_change() Prepare for spin lock assertion; move non-trivial assignment into function body. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
fba594a8 |
|
02-Sep-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Remove unsafe x_char optimization uart_unthrottle() attempts to avoid sending START and the previous x_char if the previous x_char has not yet been sent. However, this optimization could leave the sender in a throttled state; for example, if the sender is throttled and this unthrottle coincides with a manual tcflow(TCION) from user-space, then neither START would be sent. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c235ccc1 |
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02-Sep-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Fix x_char race The UART driver is expected to clear port->x_char after transmission while holding the port->lock. However, the serial core fails to take the port->lock before assigning port->xchar. This allows for the following race CPU 0 | CPU 1 | | serial8250_handle_irq | ... | serial8250_tx_chars | if (port->x_char) | serial_out(up, UART_TX, port->x_char) uart_send_xchar | port->x_char = ch | | port->x_char = 0 port->ops->start_tx() | | The x_char on CPU 0 will never be sent. Take the port->lock in uart_send_xchar() before assigning port->x_char. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
99abf3b9 |
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02-Sep-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: Style fix Unwrap if() conditional; no functional change. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a6eec92e |
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02-Sep-2014 |
Peter Hurley <peter@hurleysoftware.com> |
Revert "serial: uart: add hw flow control support configuration" This reverts commit 06aa82e498c144c7784a6f3d3b55458b272d6146. This commit purports to enable auto CTS flow control for the 8250 UART driver. However, the 8250 UART driver already supports auto CTS flow control via UART_CAP_AFE and UART_CAP_EFR. Indeed, this patch introduces another DT attribute for which an existing firmware flag already exists ("auto-flow-control"). Furthermore, the use of UPF_HARD_FLOW requires the UART driver to define .throttle and .unthrottle methods, neither of which are defined for the 8250 UART driver (which will result in a NULL ptr dereference). Finally, this patch supposes to fix existing bugs in the serial core for auto CTS-enabled hardware, but does not include the class of hardware for which these bugs exist. CC: Murali Karicheri <m-karicheri2@ti.com> CC: Rob Herring <robh+dt@kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
2f2dafe7 |
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01-Sep-2014 |
Sudip Mukherjee <sudipm.mukherjee@gmail.com> |
serial: serial_core.c: printk replacement printk replaced with corresponding dev_* . fixed two broken user-visible strings used by the corresponding printk. the null check for uport->dev and port->dev is removed as dev_* will check for null while printing. printing of dev_name(uport->dev) and dev_name(port->dev) also removed as those are being printed by dev_* . Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c2b703b8 |
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23-Jul-2014 |
Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> |
serial/core: Fix too big allocation for attribute member Current code allocates too much data for tty_groups member of uart_port struct, so fix it. Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
266dcff0 |
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15-Jul-2014 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
Serial: allow port drivers to have a default attribute group Some serial drivers (like 8250), want to add sysfs files. We need to do so in a race-free way, so allow any port to be able to specify an attribute group that should be added at device creation time. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c18b55fd |
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16-Jun-2014 |
Peter Hurley <peter@hurleysoftware.com> |
tty: serial: Fix termios/port flags mismatch Uart port drivers may reconfigure termios settings based on available hardware support; set/clear ASYNC_CTS_FLOW and ASYNC_CHECK_CD _after_ calling the port driver's .set_termios method. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
e359a4e3 |
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16-Jun-2014 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Remove tty_hung_up_p() tests from tty drivers' open() Since at least before 2.6.30, it has not been possible to observe a hung up file pointer in a tty driver's open() method unless/until the driver open() releases the tty_lock() (eg., before blocking). This is because tty_open() adds the file pointer while holding the tty_lock() _and_ doesn't release the lock until after calling the tty driver's open() method. [ Before tty_lock(), this was lock_kernel(). ] Since __tty_hangup() first waits on the tty_lock() before enumerating and hanging up the open file pointers, either __tty_hangup() will wait for the tty_lock() or tty_open() will not yet have added the file pointer. For example, CPU 0 | CPU 1 | tty_open | __tty_hangup .. | .. tty_lock | .. tty_reopen | tty_lock / blocks .. | tty_add_file(tty, filp) | .. | tty->ops->open(tty, filp) | tty_port_open | tty_port_block_til_ready | .. | while (1) | .. | tty_unlock | / unblocks schedule | for each filp on tty->tty_files | f_ops = tty_hung_up_fops; | .. | tty_unlock tty_lock | .. | tty_unlock | Note that since tty_port_block_til_ready() and similar drop the tty_lock while blocking, when woken, the file pointer must then be tested for having been hung up. Also, fix bit-rotted drivers that used extra_count to track the port->count bump. CC: Mikael Starvik <starvik@axis.com> CC: Samuel Ortiz <samuel@sortiz.org> CC: "David S. Miller" <davem@davemloft.net> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
ddc7b758 |
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16-Jun-2014 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Move tty->closing from port lock critical section tty->closing informs the line discipline that the hardware will be shutting down imminently, and to disable further input other than soft flow control (but to still allow additional output). However, the tty lock is the necessary lock for preventing concurrent changes to tty->closing. As shown by the call-tree audit [1] of functions that modify tty->closing, the tty lock is already held for those functions. [1] Call-tree audit of functions that modify tty->closing * does not include call tree to tty_port_close(), tty_port_close_start(), or tty_port_close_end() which is already documented in 'tty: Document locking for tty_port_close{,start,end}' that shows callers to those 3 functions hold the tty lock tty_release() tty->ops->close() --+ | __tty_hangup() | tty->ops->close() --+ | mp_close():drivers/staging/sb105x/sb_pci_mp.c dngc_tty_close():drivers/staging/dgnc/dgnc_tty.c dgap_tty_close():drivers/staging/dgap/dgap_tty.c dgrp_tty_close():drivers/staging/dgrp/dgrp_tty.c rp_close():drivers/tty/rocket.c hvsi_close():drivers/tty/hvc/hvsi.c rs_close():drivers/tty/serial/68328serial.c rs_close():drivers/tty/serial/crisv10.c uart_close():drivers/tty/serial/serial_core.c isdn_tty_close():drivers/isdn/i4l/isdn_tty.c tty3215_close():drivers/s390/char/con3215.c tty_open() tty_ldisc_setup() ----+ | __tty_hangup() | tty_ldisc_hangup() ---+ | tty_set_ldisc() --------+ tty_ldisc_restore() --+ | +- tty_ldisc_open() ld->ops->open() --+ | +- n_tty_open() Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
ae84db96 |
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09-Jul-2014 |
Peter Hurley <peter@hurleysoftware.com> |
serial: core: Preserve termios c_cflag for console resume When a tty is opened for the serial console, the termios c_cflag settings are inherited from the console line settings. However, if the tty is subsequently closed, the termios settings are lost. This results in a garbled console if the console is later suspended and resumed. Preserve the termios c_cflag for the serial console when the tty is shutdown; this reflects the most recent line settings. Fixes: Bugzilla #69751, 'serial console does not wake from S3' Reported-by: Valerio Vanni <valerio.vanni@inwind.it> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
1fdc3106 |
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03-Jun-2014 |
Alexander Shiyan <shc_work@mail.ru> |
serial: core: Make enable_ms() optional This patch makes enable_ms() optional, so we can eliminate a lot of empty enable_ms() implementations from driver code. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a208ffd2 |
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27-Mar-2014 |
Grant Likely <grant.likely@linaro.org> |
of: Enable console on serial ports specified by /chosen/stdout-path If the devicetree specifies a serial port as a stdout device, then the kernel can use it as the default console if nothing else was selected on the command line. For any serial port that uses the uart_add_one_port() feature, the uart_add_one_port() has all the information needed to automatically enable the console device, which is what this patch does. With this change applied, a device tree platform can be booted without any console= parameters on the command line and the kernel will still be able to determine its console. Tested on QEMU Versatile model and i.MX Signed-off-by: Grant Likely <grant.likely@linaro.org> Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
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#
06aa82e4 |
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01-May-2014 |
Murali Karicheri <m-karicheri2@ti.com> |
serial: uart: add hw flow control support configuration 8250 uart driver currently supports only software assisted hw flow control. The software assisted hw flow control maintains a hw_stopped flag in the tty structure to stop and start transmission and use modem status interrupt for the event to drive the handshake signals. This is not needed if hw has flow control capabilities. This patch adds a DT attribute for enabling hw flow control for a uart port. Also skip stop and start if this flag is present in flag field of the port structure. Signed-off-by: Murali Karicheri <m-karicheri2@ti.com> CC: Rob Herring <robh+dt@kernel.org> CC: Pawel Moll <pawel.moll@arm.com> CC: Mark Rutland <mark.rutland@arm.com> CC: Ian Campbell <ijc+devicetree@hellion.org.uk> CC: Kumar Gala <galak@codeaurora.org> CC: Randy Dunlap <rdunlap@infradead.org> CC: Jiri Slaby <jslaby@suse.cz> CC: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c7d44a02 |
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21-Apr-2014 |
Doug Anderson <dianders@chromium.org> |
serial_core: Commonalize crlf when working w/ a non open console port In (efe2f29 kgdboc,kdb: Allow kdb to work on a non open console port) support was added to directly use the "write_char" functions when doing kdb over a non-open console port. This is great, but it ends up bypassing the normal code in uart_console_write() that adds a carriage return before any newlines. There appears to have been a trend to add this support directly in some console driver's poll_put_char() functions. This had a few side effects, including: - In this case we were doing LFCR, not CRLF. This was fixed in uart_console_write() back in (d358788 [SERIAL] kernel console should send CRLF not LFCR) - Not all serial drivers had the LFCR code in their poll_put_char() functions. In my case I was running serial/samsung.c which lacked it. I've moved the handling to uart_poll_put_char() to fix the above problems. Now when I use kdb (and don't point console= to the same UART) I no longer get: [0]kdb> [0]kdb> [0]kdb> Signed-off-by: Doug Anderson <dianders@chromium.org> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
7deb39ed |
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22-Apr-2014 |
Thomas Pfaff <tpfaff@pcs.com> |
serial_core: fix uart PORT_UNKNOWN handling While porting a RS485 driver from 2.6.29 to 3.14, i noticed that the serial tty driver could break it by using uart ports that it does not own : 1. uart_change_pm ist called during uart_open and calls the uart pm function without checking for PORT_UNKNOWN. The fix is to move uart_change_pm from uart_open to uart_port_startup. 2. The return code from the uart request_port call in uart_set_info is not handled properly, leading to the situation that the serial driver also thinks it owns the uart ports. This can triggered by doing following actions : setserial /dev/ttyS0 uart none # release the uart ports modprobe lirc-serial # or any other device that uses the uart setserial /dev/ttyS0 uart 16550 # gives no error and the uart tty driver # can use the ports as well Signed-off-by: Thomas Pfaff <tpfaff@pcs.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
bf903c0c |
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27-Mar-2014 |
Geert Uytterhoeven <geert+renesas@glider.be> |
serial_core: Fix pm imbalance on unbind When a serial port is closed, uart_close() takes care of shutting down the hardware, and powering it down. When a serial port is unbound while in use, uart_close() bypasses all of this, as this is supposed to be done through uart_hangup() (invoked via tty_vhangup() in uart_remove_one_port()). However, uart_hangup() does not set the hardware's power state, leaving it powered up. This may also lead to unbounded nesting counts in clock and power management, depending on their internal implementation. Make sure to power down the port in uart_hangup(), except when the port is used as a serial console. For serial consoles, this operation must be postponed until after the port becomes completely unused. This case is not fixed yet, as it depends on a (future) fix for the tty->count vs. port->count imbalance on failed uart_open(). After this, the module clock used by the sh-sci driver is disabled on unbind while the serial port is in use. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
717f3bba |
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24-Mar-2014 |
Seth Bollinger <sethb@digi.com> |
serial_core: Fix conditional start_tx on ring buffer not empty If the serial_core ring buffer empties just as the tty layer receives an XOFF, then start_tx will never be called when the tty layer receives an XON as the serial_core ring buffer is empty. This will possibly leave a few bytes trapped in the fifo for drivers that disable the transmitter when flow controlled. Signed-off-by: Seth Bollinger <sethb@digi.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
4ed94cd4 |
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17-Mar-2014 |
Geert Uytterhoeven <geert+renesas@linux-m68k.org> |
serial_core: Avoid NULL pointer dereference in uart_close() When unbinding a serial driver that's being used as a serial console, the kernel may crash with a NULL pointer dereference in a uart_*() function called from uart_close () (e.g. uart_flush_buffer() or uart_chars_in_buffer()). To fix this, let uart_close() check for port->count == 0. If this is the case, bail out early. Else tty_port_close_start() will make the port counts inconsistent, printing out warnings like tty_port_close_start: tty->count = 1 port count = 0. and tty_port_close_start: count = -1 and once uport == NULL, it will also crash. Also fix the related crash in pr_debug() by checking for a non-NULL uport first. Detailed description: On driver unbind, uart_remove_one_port() is called. Basically it; - marks the port dead, - calls tty_vhangup(), - sets state->uart_port = NULL. What will happen depends on whether the port is just in use by e.g. getty, or was also opened as a console. A. If the tty was not opened as a console: - tty_vhangup() will (in __tty_hangup()): - mark all file descriptors for this tty hung up by pointing them to hung_up_tty_fops, - call uart_hangup(), which sets port->count to 0. - A subsequent uart_open() (this may be through /dev/ttyS*, or through /dev/console if this is a serial console) will fail with -ENXIO as the port was marked dead, - uart_close() after the failed uart_open() will return early, as tty_hung_up_p() (called from tty_port_close_start()) will notice it was hung up. B. If the tty was also opened as a console: - tty_vhangup() will (in __tty_hangup()): - mark non-console file descriptors for this tty hung up by pointing them to hung_up_tty_fops, - NOT call uart_hangup(), but instead call uart_close() for every non-console file descriptor, so port->count will still have a non-zero value afterwards. - A subsequent uart_open() will fail with -ENXIO as the port was marked dead, - uart_close() after the failed uart_open() starts to misbehave: - tty_hung_up_p() will not notice it was hung up, - As port->count is non-zero, tty_port_close_start() will decrease port->count, making the tty and port counts inconsistent. Later, warnings like these will be printed: tty_port_close_start: tty->count = 1 port count = 0. and tty_port_close_start: count = -1 - If all of this happens after state->uart_port was set to zero, a NULL pointer dereference will happen. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
4c6d5b4d |
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17-Mar-2014 |
Geert Uytterhoeven <geert+renesas@linux-m68k.org> |
serial_core: Get a reference for port->tty in uart_remove_one_port() Suggested-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
015355b7 |
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11-Mar-2014 |
Geert Uytterhoeven <geert+renesas@linux-m68k.org> |
serial_core: Grammar s/ports/port's/ Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-serial@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
02088ca6 |
|
11-Mar-2014 |
Geert Uytterhoeven <geert+renesas@linux-m68k.org> |
serial_core: Spelling s/contro/control/ Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-serial@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
5f5c9ae5 |
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28-Feb-2014 |
Geert Uytterhoeven <geert+renesas@linux-m68k.org> |
serial_core: Unregister console in uart_remove_one_port() If the serial port being removed is used as a console, it must also be unregistered from the console subsystem using unregister_console(). uart_ops.release_port() will release resources (e.g. iounmap() the serial port registers), causing a crash on subsequent kernel output if the console is still registered. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
42b6a1ba |
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17-Oct-2013 |
Randy Witt <rewitt@declaratino.com> |
serial_core: Don't re-initialize a previously initialized spinlock. The uart_set_options() code unconditionally initalizes the spinlock on the port. This can cause a deadlock in some situations. One instance that exposed the problem, was when writing to /sys/module/kgdboc/parameters/kgdboc to use ttyS0 when the console is already running on ttyS0. If the spinlock is re-initialized while the lock is held due to output to the console, there is a deadlock. Assume the spinlock is initialized if the port is a console. Signed-off-by: Randy Witt <rewitt@declaratino.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
7d12b976 |
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12-Jul-2013 |
Kees Cook <keescook@chromium.org> |
serial: report base_baud after initialization Some serial ports will not use the standard base baud rate. Report this after initialization so it might be discovered and used for early console configuration. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
cf0ebee0 |
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15-May-2013 |
Sourav Poddar <sourav.poddar@ti.com> |
serial: Move "uart_console" def to core header file. Move "uart_console" definition to serial core header file, so that it can be used by serial drivers. Get rid of the uart_console defintion from mpc52xx_uart driver. Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Rajendra nayak <rnayak@ti.com> Reviewed-by: Felipe Balbi <balbi@ti.com> Reviewed-by: Kevin Hilman <khilman@linaro.org> Tested-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Sourav Poddar <sourav.poddar@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
5a65dcc0 |
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15-Apr-2013 |
Federico Vaga <federico.vaga@gmail.com> |
serial_core.c: add put_device() after device_find_child() The serial core uses device_find_child() but does not drop the reference to the retrieved child after using it. This patch add the missing put_device(). What I have done to test this issue. I used a machine with an AMBA PL011 serial driver. I tested the patch on next-20120408 because the last branch [next-20120415] does not boot on this board. For test purpose, I added some pr_info() messages to print the refcount after device_find_child() (lines: 1937,2009), and after put_device() (lines: 1947, 2021). Boot the machine *without* put_device(). Then: echo reboot > /sys/power/disk echo disk > /sys/power/state [ 87.058575] uart_suspend_port:1937 refcount 4 [ 87.058582] uart_suspend_port:1947 refcount 4 [ 87.098083] uart_resume_port:2009refcount 5 [ 87.098088] uart_resume_port:2021 refcount 5 echo disk > /sys/power/state [ 103.055574] uart_suspend_port:1937 refcount 6 [ 103.055580] uart_suspend_port:1947 refcount 6 [ 103.095322] uart_resume_port:2009 refcount 7 [ 103.095327] uart_resume_port:2021 refcount 7 echo disk > /sys/power/state [ 252.459580] uart_suspend_port:1937 refcount 8 [ 252.459586] uart_suspend_port:1947 refcount 8 [ 252.499611] uart_resume_port:2009 refcount 9 [ 252.499616] uart_resume_port:2021 refcount 9 The refcount continuously increased. Boot the machine *with* this patch. Then: echo reboot > /sys/power/disk echo disk > /sys/power/state [ 159.333559] uart_suspend_port:1937 refcount 4 [ 159.333566] uart_suspend_port:1947 refcount 3 [ 159.372751] uart_resume_port:2009 refcount 4 [ 159.372755] uart_resume_port:2021 refcount 3 echo disk > /sys/power/state [ 185.713614] uart_suspend_port:1937 refcount 4 [ 185.713621] uart_suspend_port:1947 refcount 3 [ 185.752935] uart_resume_port:2009 refcount 4 [ 185.752940] uart_resume_port:2021 refcount 3 echo disk > /sys/power/state [ 207.458584] uart_suspend_port:1937 refcount 4 [ 207.458591] uart_suspend_port:1947 refcount 3 [ 207.498598] uart_resume_port:2009 refcount 4 [ 207.498605] uart_resume_port:2021 refcount 3 The refcount correctly handled. Signed-off-by: Federico Vaga <federico.vaga@gmail.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d9dda78b |
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31-Mar-2013 |
Al Viro <viro@zeniv.linux.org.uk> |
procfs: new helper - PDE_DATA(inode) The only part of proc_dir_entry the code outside of fs/proc really cares about is PDE(inode)->data. Provide a helper for that; static inline for now, eventually will be moved to fs/proc, along with the knowledge of struct proc_dir_entry layout. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
bc80fbe4 |
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06-Feb-2013 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Remove ancient hardpps() hardpps() functionality is provided through the N_PPS line discipline now. The new function signature was added in commit 025b40ab (2011-01-12). There was no previous macro or function hardpps(), at least since before the initial commit of v2.6.12 in 2005. It's unlikely this code has been compiled since. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: George Spelvin <linux@horizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
42381572 |
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10-Feb-2013 |
George Spelvin <linux@horizon.com> |
pps: Additional cleanups in uart_handle_dcd_change An extension of the previous commit, there is no semantic change here, just fewer lines of source code. Signed-off-by: George Spelvin <linux@horizon.com> Acked-by: Rodolfo Giometti <giometti@enneenne.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
593fb1ae4 |
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12-Feb-2013 |
George Spelvin <linux@horizon.com> |
pps: Move timestamp read into PPS code proper The PPS (Pulse-Per-Second) line discipline has developed a number of unhealthy attachments to core tty data and functions, ultimately leading to its breakage. The previous patches fixed the crashing. This one reduces coupling further by eliminating the timestamp parameter from the dcd_change ldisc method. This reduces header file linkage and makes the extension more generic, and the timestamp read is delayed only slightly, from just before the ldisc->ops->dcd_change method call to just after. Fix attendant build breakage in drivers/tty/n_tty.c drivers/tty/tty_buffer.c drivers/staging/speakup/selection.c drivers/staging/dgrp/dgrp_*.c Cc: William Hubbs <w.d.hubbs@gmail.com> Cc: Chris Brannon <chris@the-brannons.com> Cc: Kirk Reiser <kirk@braille.uwo.ca> Cc: Samuel Thibault <samuel.thibault@ens-lyon.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: George Spelvin <linux@horizon.com> Acked-by: Rodolfo Giometti <giometti@enneenne.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
b342dd51 |
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27-Dec-2012 |
Chen Gang <gang.chen@asianux.com> |
drivers/tty/serial: extern function which for release resource, need check pointer, before free it for extern function uart_remove_one_port: need check pointer whether be NULL, before the main work. just like what the other extern function uart_add_one_port has done. uart_add_one_port and uart_remove_one_port are pair information: for the callers (such as drivers/tty/serial/jsm: jsm_tty.c, jsm_driver.c) they realy assume that: they still can call uart_remove_one_port, after uart_add_one_port failed we (as an extern function), have to understand it (just like kfree). Signed-off-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d6c53c0e |
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03-Jan-2013 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: move low_latency to tty_port One point is to have less places where we actually need tty pointer. The other is that low_latency is bound to buffer processing and buffers are now in tty_port. So it makes sense to move low_latency to tty_port too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
92a19f9c |
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03-Jan-2013 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: switch tty_insert_flip_char Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. tty_insert_flip_char is the next one to proceed. This one is used all over the code, so the patch is huge. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
ef4f527c |
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26-Dec-2012 |
Kevin Cernekee <cernekee@gmail.com> |
tty: Fix comments that reference BKL, eventd, old paths Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
6f538fe3 |
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07-Dec-2012 |
Linus Walleij <linus.walleij@linaro.org> |
tty: serial core: decouple pm states from ACPI The serial core is using power states lifted from ACPI for no good reason. Remove this reference from the documentation and alter all users to use an enum specific to the serial core instead, and define it in <linux/serial_core.h>. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Alan Cox <alan@linux.intel.com> Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
fd985e1d |
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26-Nov-2012 |
Andrew Morton <akpm@linux-foundation.org> |
drivers/tty/serial/serial_core.c: clean up HIGH_BITS_OFFSET usage serial_core.c usually does if (HIGH_BITS_OFFSET) expr-involving-HIGH_BITS_OFFSET() at least to avoid generating useless code on 32-bit machines, where HIGH_BITS_OFFSET is zero. Do that in uart_get_attr_port(). Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
191c5f10 |
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15-Nov-2012 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: call tty_port_destroy in the rest of drivers After commit "TTY: move tty buffers to tty_port", the tty buffers are not freed in some drivers. This is because tty_port_destructor is not called whenever a tty_port is freed. This was an assumption I counted with but was unfortunately untrue. So fix the drivers to fulfil this assumption. To be sure, the TTY buffers (and later some stuff) are gone along with the tty_port, we have to call tty_port_destroy at tear-down places. This is mostly where the structure containing a tty_port is freed. This patch does exactly that -- put tty_port_destroy at those places. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
7a876b39 |
|
06-Nov-2012 |
Alan Cox <alan@linux.intel.com> |
serial: cast before shifting on port io Without this we will shift data into oblivion and give wrong results on some configurations Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
9aba8d5b |
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17-Apr-2012 |
Russell King <rmk+kernel@arm.linux.org.uk> |
SERIAL: core: add throttle/unthrottle callbacks for hardware assisted flow control Add two callbacks for hardware assisted flow control; we need to know when the tty layers want us to stop and restart due to their buffer levels. Call a driver specific throttle/unthrottle function if and only if the driver indicates that it is using an enabled hardware assisted flow control method, otherwise fall back to the non-hardware assisted methods. Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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#
dba05832 |
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17-Apr-2012 |
Russell King <rmk+kernel@arm.linux.org.uk> |
SERIAL: core: add hardware assisted h/w flow control support Ports which are handling h/w flow control in hardware must not have their RTS state altered depending on the tty's hardware-stopped state. Avoid this additional logic when setting the termios state. Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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#
2cbacafd |
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17-Apr-2012 |
Russell King <rmk+kernel@arm.linux.org.uk> |
SERIAL: core: add hardware assisted s/w flow control support Ports which are capable of handling s/w flow control in hardware to know when the s/w flow control termios settings are changed. Add a flag to allow the low level serial drivers to indicate that they support this, and these changes should be propagated to them. Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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#
dec94e70 |
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24-Sep-2012 |
Russell King <rmk+kernel@arm.linux.org.uk> |
SERIAL: core: use local variable uport in uart_set_termios() This is to make the following change more clear. Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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#
373bac4c |
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29-Oct-2012 |
Alan Cox <alan@linux.intel.com> |
uart: add other serial core layer get attributes Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
9f109694 |
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29-Oct-2012 |
Alan Cox <alan@linux.intel.com> |
uart: tidy the uart_get_info API We pass both port and state because the original caller had both to hand. With all the attribute callers this won't be true so do the conversion in the function itself. The current callers all do lock/query/unlock. This won't be true for future set based cases but there are plenty of get ones that will exist so split the code with a helper for the future cases. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
bebe73e3 |
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29-Oct-2012 |
Alan Cox <alan@linux.intel.com> |
uart: update the sysfs handler to use uart_get_info The two patches needed are now in the tree. The first added the sysfs interface and directly accesses the uartclk. The second provides a proper interface for getting the values. Wire them together. This formes a basis for both get and set methods for any of the other uart properties and we can now fill them out further. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c7f3e708 |
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24-Sep-2012 |
Anton Vorontsov <anton.vorontsov@linaro.org> |
tty/serial/core: Introduce poll_init callback It was noticed that polling drivers (like KGDB) are not able to use serial ports if the ports were not previously initialized via console. I.e. when booting with console=ttyAMA0 kgdboc=ttyAMA0, everything works fine, but with console=ttyFOO kgdboc=ttyAMA0, the kgdboc doesn't work. This is because we don't initialize the hardware. Calling ->startup() is not an option, because drivers request interrupts there, and drivers fail to handle situations when tty isn't opened with interrupts enabled. So, we have to implement a new callback (actually, tty_ops already have a similar callback), which does everything needed to initialize just the hardware. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
43eca0ae |
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19-Sep-2012 |
Alan Cox <alan@linux.intel.com> |
serial_core: Fix race in uart_handle_dcd_change If a serial driver is called post hangup with a second DCD event then we will attempt to get the ldisc of NULL. Check we have a tty before trying to do anything with it. This is still only safe within the uart layer if the caller holds the relevant uart locks. We could do with a version where the tty is passed for more general use. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
b1b79916 |
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06-Sep-2012 |
Tomas Hlavacek <tmshlvck@gmail.com> |
tty_register_device_attr updated for tty-next Added tty_device_create_release() and bound to dev->release in tty_register_device_attr(). Added tty_port_register_device_attr() and used in uart_add_one_port() instead of tty_register_device_attr(). Signed-off-by: Tomas Hlavacek <tmshlvck@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
6915c0e4 |
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05-Sep-2012 |
Tomas Hlavacek <tmshlvck@gmail.com> |
tty: uartclk value from serial_core exposed to sysfs Added file /sys/devices/.../tty/ttySX/uartclk to allow reading uartclk value in struct uart_port in serial_core via sysfs. tty_register_device() has been generalized and refactored in order to add support for setting drvdata and attribute_group to the device. Signed-off-by: Tomas Hlavacek <tmshlvck@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
37cd0c99 |
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05-Sep-2012 |
Fengguang Wu <fengguang.wu@intel.com> |
serial_core: fix sizeof(pointer) sizeof when applied to a pointer typed expression gives the size of the pointer. Generated by: scripts/coccinelle/misc/noderef.cocci Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
f21ec3d2 |
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22-Aug-2012 |
Huang Shijie <shijie8@gmail.com> |
serial: add a new helper function In most of the time, the driver needs to check if the cts flow control is enabled. But now, the driver checks the ASYNC_CTS_FLOW flag manually, which is not a grace way. So add a new wraper function to make the code tidy and clean. Signed-off-by: Huang Shijie <shijie8@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
7ba2e769 |
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04-Sep-2012 |
Alan Cox <alan@linux.intel.com> |
tty: Split the serial_core helpers for setserial into two We want them split so that we can call them from setserial functionality where we copy to/from user space and do the locking, but also from sysfs where in future we'll want to came them within a sysfs context. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
734cc178 |
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07-Aug-2012 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: use tty_port_register_device Currently we have no way to assign tty->port while performing tty installation. There are two ways to provide the link tty_struct => tty_port. Either by calling tty_port_install from tty->ops->install or tty_port_register_device called instead of tty_register_device when the device is being set up after connected. In this patch we modify most of the drivers to do the latter. When the drivers use tty_register_device and we have tty_port already, we switch to tty_port_register_device. So we have the tty_struct => tty_port link for free for those. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
24a7d449 |
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23-May-2012 |
Corbin <corbinat@gmail.com> |
serial_core: Update buffer overrun statistics. Currently, serial drivers don't report buffer overruns. When a buffer overrun occurs, tty_insert_flip_char returns 0, and no attempt is made to insert that same character again (i.e. it is lost). This patch reports buffer overruns via the buf_overrun field in the port's icount structure. Signed-off-by: Corbin Atkinson <corbin.atkinson@xxxxxx> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
adc8d746 |
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14-Jul-2012 |
Alan Cox <alan@linux.intel.com> |
tty: move the termios object into the tty This will let us sort out a whole pile of tty related races. The alternative would be to keep points and refcount the termios objects. However 1. They are tiny anyway 2. Many devices don't use the stored copies 3. We can remove a pty special case Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
dabfb351 |
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23-May-2012 |
Corbin <corbinat@gmail.com> |
serial_core: Update buffer overrun statistics. Currently, serial drivers don't report buffer overruns. When a buffer overrun occurs, tty_insert_flip_char returns 0, and no attempt is made to insert that same character again (i.e. it is lost). This patch reports buffer overruns via the buf_overrun field in the port's icount structure. Signed-off-by: Corbin Atkinson <corbin.atkinson@xxxxxx> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
55e4b8b4 |
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15-May-2012 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
Revert "serial_core: Update buffer overrun statistics." This reverts commit 642180871bc91afebb6ccf40d1615a7dd33699a3. Buffer overruns are for hardware reported overruns, not software ones, which will only happen if we run out of memory and you will get lots of -ENOMEM errors at the same time. Thanks to Alan Cox for catching this. Reported-by: Alan Cox <alan@linux.intel.com> Cc: Corbin Atkinson <corbinat@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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1e66cded |
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14-May-2012 |
Alan Cox <alan@linux.intel.com> |
tty: Allow uart_register/unregister/register This is legitimate but because we don't clear the drv->state pointer in the unregister code causes a bogus BUG(). Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=42880 Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
64218087 |
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03-May-2012 |
Corbin Atkinson <corbinat@gmail.com> |
serial_core: Update buffer overrun statistics. Currently, serial drivers don't report buffer overruns. When a buffer overrun occurs, tty_insert_flip_char returns 0, and no attempt is made to insert that same character again (i.e. it is lost). This patch reports buffer overruns via the buf_overrun field in the port's icount structure. Signed-off-by: Corbin Atkinson <corbin.atkinson@ni.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
2f16669d |
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05-Mar-2012 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: remove re-assignments to tty_driver members All num, magic and owner are set by alloc_tty_driver. No need to re-set them on each allocation site. pti driver sets something different to what it passes to alloc_tty_driver. It is not a bug, since we don't use the lines parameter in any way. Anyway this is fixed, and now we do the right thing. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Tilman Schmidt <tilman@imap.cc> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
77359835 |
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19-Jan-2012 |
Simon Glass <sjg@chromium.org> |
serial: Fix wakeup init logic to speed up startup The synchronize_rcu() call resulting from making every serial driver wake-up capable (commit b3b708fa) slows boot down on my Tegra2x system (with CONFIG_PREEMPT disabled). But this is avoidable since it is the device_set_wakeup_enable() and then subsequence disable which causes the delay. We might as well just make the device wakeup capable but not actually enable it for wakeup until needed. Effectively the current code does this: device_set_wakeup_capable(dev, 1); device_set_wakeup_enable(dev, 1); device_set_wakeup_enable(dev, 0); We can just drop the last two lines. Before this change my boot log says: [ 0.227062] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled [ 0.702928] serial8250.0: ttyS0 at MMIO 0x70006040 (irq = 69) is a Tegra after: [ 0.227264] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled [ 0.227983] serial8250.0: ttyS0 at MMIO 0x70006040 (irq = 69) is a Tegra for saving of 450ms. Suggested-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
97d24634 |
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20-Dec-2011 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
serial: use DIV_ROUND_CLOSEST instead of open coding it Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
c0d92be6 |
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09-Nov-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, extract uart_port_startup Extract ASYNC_INITIALIZED/TTY_IO_ERROR handling from uart_startup. This will be useful for tty port helpers. These flags are handled by the helpers instead. So we create a new function uart_port_startup without touching these flags there. And we keep uart_startup with the exact behavior as before. We need that one because we start/stop the device from other paths than open/close/hangup. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
b922e19d |
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09-Nov-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, fill uart_port_shutdown Let's fill the port_ops->shutdown. We will need this for hangup and close port helpers. We don't need to touch DTR/RTS registers in uart_port_shutdown. They are set to off from port_close_start properly already. Also we don't need to pin the TTY_IO_ERROR bit. This will be done in close/hangup paths. We leave uart_shutdown as is, because it is used (and will be) from several paths now. Like from suspend. The point is to not touch ASYNC_INITIALIZED bit. It will be set (and checked) properly by the tty port helpers. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
0b1db830 |
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09-Nov-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, define uart_port_activate/shutdown This is a preparation for the next patches which will move the stuff from uart_open and uart_close/hangup here. Then we will use tty_port_* helpers. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
1c7b13c4 |
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09-Nov-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, inline uart_get We need to expand uart_get into uart_open. We need it to move on with conversion to use tty_port_open helper. After we do this, the code will be much more similar to what tty_port_open does. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
b39c49a0 |
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09-Nov-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, do not touch tty->alt_speed It is not used at all, so no need to play any games with that. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
cf75525f |
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09-Nov-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, document few functions Just put a kernel-doc comment to uart_change_pm and uart_insert_char. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
d30ccf08 |
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09-Nov-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, use tty_port_close_start helper After the previous patches, the code is almost identical. There are few differences in the helper code: 1) flush_buffer when flow_stopped * when a user doesn't care about the data, delete it anyways 2) ASYNCB_INITIALIZED test before wait_until_sent_from * obviously, there is nothing to wait for if the port is dead 3) drain_delay wait * we don't set drain_delay So we can use the helper now. It indeed removes a bunch of duplicated code. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
4cb0fbfd |
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09-Nov-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, switch closing_wait and close_delay to jiffies As the tty_port helpers think closing_wait and close_delay are in jiffies and we want to use the helpers (next patches), we have to switch the closing_wait and close_delay from ms to jiffies now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
027d7dac |
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09-Nov-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, cleanup include file There are some functions (uart_handle_dcd_change, _handle_cts_change, _insert_char) which are big enough to not be inlined. So move them from .h to .c. We need to export them so that modules can actually use them. They will be even bigger when we introduce tty refcounting to them. While at it, cleanup the "Proud member of Uglyhacks'R'US". It means, define uart_handle_sysrq_char only when SUPPORT_SYSRQ is set. Otherwise define it as a macro. This is needed for some arm driver where the second parameter is undefined if expanded. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
d208a3bf |
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19-Oct-2011 |
Doug Anderson <dianders@chromium.org> |
TTY: serial_core: Fix crash if DCD drop during suspend This crash was showing up 100% of the time on Tegra CPUs when an agetty was running on the serial port and the console was not running on the serial port. The reason the Tegra saw it so reliably is that the Tegra CPU internally ties DTR to DCD/DSR. That means when we dropped DTR during suspend we would get always get an immediate DCD drop. The specific order of operations that were running: * uart_suspend_port() would be called to put the uart in suspend mode * we'd drop DTR (ops->set_mctrl(uport, 0)). * the DTR drop would be looped back in the CPU to be a DCD drop. * the DCD drop would look to the serial driver as a hangup * the hangup would call uart_shutdown() * ... suspend / resume happens ... * uart_resume_port() would be called and run the code in the (port->flags & ASYNC_SUSPENDED) block, which would startup the port (and enable tx again). * Since the UART would be available for tx, we'd immediately get an interrupt, eventually calling transmit_chars() * The transmit_chars() function would crash. The first crash would be a dereference of a NULL tty member, but since the port has been shutdown that was just a symptom. I have proposed a patch that would fix the Tegra CPUs here (see https://lkml.org/lkml/2011/10/11/444 - tty/serial: Prevent drop of DCD on suspend for Tegra UARTs). However, even with that fix it is still possible for systems that have an externally visible DCD line to see a crash if the DCD drops at just the right time during suspend: thus this patch is still useful. Signed-off-by: Doug Anderson <dianders@chromium.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
94abc56f |
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05-Sep-2011 |
Ning Jiang <ning.jiang@marvell.com> |
serial-core: power up uart port early before we do set_termios when resuming The following patch removed uart_change_pm() in uart_resume_port(): commit 5933a161abcb8d83a2c145177f48027c3c0a8995 Author: Yin Kangkai <kangkai.yin@linux.intel.com> serial-core: reset the console speed on resume It will break the pxa serial driver when the system resumes from suspend mode as it will try to set baud rate divider register in set_termios but with clock off. The register value can not be set correctly on some platform if the clock is disabled. The pxa driver will check the value and report the following warning: ------------[ cut here ]------------ WARNING: at drivers/tty/serial/pxa.c:545 serial_pxa_set_termios+0x1dc/0x250() Modules linked in: [<c0281f30>] (unwind_backtrace+0x0/0xf0) from [<c029341c>] (warn_slowpath_common+0x4c/0x64) [<c029341c>] (warn_slowpath_common+0x4c/0x64) from [<c029344c>] (warn_slowpath_null+0x18/0x1c) [<c029344c>] (warn_slowpath_null+0x18/0x1c) from [<c044b1e4>] (serial_pxa_set_termios+0x1dc/0x250) [<c044b1e4>] (serial_pxa_set_termios+0x1dc/0x250) from [<c044a840>] (uart_resume_port+0x128/0x2dc) [<c044a840>] (uart_resume_port+0x128/0x2dc) from [<c044bbe0>] (serial_pxa_resume+0x18/0x24) [<c044bbe0>] (serial_pxa_resume+0x18/0x24) from [<c0454d34>] (platform_pm_resume+0x40/0x4c) [<c0454d34>] (platform_pm_resume+0x40/0x4c) from [<c0457ebc>] (pm_op+0x68/0xb4) [<c0457ebc>] (pm_op+0x68/0xb4) from [<c0458368>] (device_resume+0xb0/0xec) [<c0458368>] (device_resume+0xb0/0xec) from [<c04584c8>] (dpm_resume+0xe0/0x194) [<c04584c8>] (dpm_resume+0xe0/0x194) from [<c0458588>] (dpm_resume_end+0xc/0x18) [<c0458588>] (dpm_resume_end+0xc/0x18) from [<c02c518c>] (suspend_devices_and_enter+0x16c/0x1ac) [<c02c518c>] (suspend_devices_and_enter+0x16c/0x1ac) from [<c02c5278>] (enter_state+0xac/0xdc) [<c02c5278>] (enter_state+0xac/0xdc) from [<c02c48ec>] (state_store+0xa0/0xbc) [<c02c48ec>] (state_store+0xa0/0xbc) from [<c0408f7c>] (kobj_attr_store+0x18/0x1c) [<c0408f7c>] (kobj_attr_store+0x18/0x1c) from [<c034a6a4>] (sysfs_write_file+0x108/0x140) [<c034a6a4>] (sysfs_write_file+0x108/0x140) from [<c02fb798>] (vfs_write+0xac/0x134) [<c02fb798>] (vfs_write+0xac/0x134) from [<c02fb8cc>] (sys_write+0x3c/0x68) [<c02fb8cc>] (sys_write+0x3c/0x68) from [<c027c700>] (ret_fast_syscall+0x0/0x2c) ---[ end trace 88289eceb4675b04 ]--- This patch fix the problem by adding the power on opertion back for uart console when console_suspend_enabled is true. Signed-off-by: Ning Jiang <ning.jiang@marvell.com> Tested-by: Mayank Rana <mrana@codeaurora.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
55956216 |
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29-Aug-2011 |
Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com> |
TTY: serial: Move mutex_unlock in uart_close function When mutex_lock is not called, mutex_unlock is sometimes called. This deletes unnecessary goto and makes modifications so that mutex_unlock is called. [ 8.304000] WARNING: at kernel/muex-debug.c:78 [ 8.304000] Modules linked in: [ 8.304000] [ 8.304000] Pid : 114, Comm: modprobe [ 8.304000] CPU : 0 Not tainted (3.1.0-rc3-next-20110826 #810) [ 8.304000] [ 8.304000] PC is at debug_mutex_unlock+0xf4/0x120 [ 8.304000] PR is at debug_mutex_unlock+0xe6/0x120 [ 8.304000] PC : 80051114 SP : 9f02de58 SR : 400081f1 TEA : 295cf4f2 [ 8.304000] R0 : 00000001 R1 : 00000000 R2 : 0000000f R3 : 00000000 [ 8.304000] R4 : 9fc63158 R5 : 00000000 R6 : 00000001 R7 : 9fe1de78 [ 8.304000] R8 : 805c6b2c R9 : 80003920 R10 : 00000000 R11 : 805c6b2c [ 8.304000] R12 : 80425ca0 R13 : 00000000 R14 : 9f02de58 [ 8.304000] MACH: 00000003 MACL: 00000000 GBR : 296e1678 PR : 80051106 [ 8.304000] [ 8.304000] Call trace: [ 8.304000] [<804236c6>] __mutex_unlock_slowpath+0x46/0x120 [ 8.304000] [<804237aa>] mutex_unlock+0xa/0x20 [ 8.304000] [<80240ed6>] uart_close+0x76/0x2c0 [ 8.304000] [<80223b98>] tty_release+0xf8/0x5c0 [ 8.304000] [<800a93a6>] lookup_object+0x26/0xa0 [ 8.304000] [<80063f6a>] call_rcu+0x8a/0xc0 [ 8.304000] [<800a944a>] put_object+0x2a/0x60 [ 8.304000] [<80003920>] arch_local_irq_restore+0x0/0x40 [ 8.304000] [<800af320>] fput+0x180/0x2c0 [ 8.304000] [<800af248>] fput+0xa8/0x2c0 [ 8.304000] [<800ab1a8>] filp_close+0x48/0xc0 [ 8.304000] [<800ab29a>] sys_close+0x7a/0x100 [ 8.304000] [<8000825a>] syscall_call+0xc/0x10 [ 8.304000] [<800ab220>] sys_close+0x0/0x100 [ 8.304000] [ 8.304000] Code: [ 8.304000] 8005110e: mov.l @r1, r1 [ 8.304000] 80051110: tst r1, r1 [ 8.304000] 80051112: bf 80051116 [ 8.304000] ->80051114: trapa #62 [ 8.304000] 80051116: mov.l @r8, r1 [ 8.304000] 80051118: tst r1, r1 [ 8.304000] 8005111a: bt.s 8005104c [ 8.304000] 8005111c: mov #0, r1 [ 8.304000] 8005111e: bra 80051056 [ 8.304000] [ 8.304000] ---[ end trace e8f8e04c313f429b ]--- Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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0b058353 |
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25-Aug-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: use tty_wait_until_sent_from_close in other drivers Let's use the newly added helper to avoid stalls in drivers which are not yet ported to tty_port helpers. Those which are broken (call tty_wait_until_sent with irqs disabled) are left untouched. They are in a deeper trouble than we are trying to solve here. This includes amiserial, 68328serial, 68360serial and crisv10. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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bafb0bd2 |
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25-Aug-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, move locking in uart_close So now, when we handle CLOSING flag, there is no point to hold port->mutex over the start of uart_close. Yes, there are still several things to reason about: * port->count etc is and always was protected by a spinlock * ->stop_rx is protected by a spinlock. Otherwise it would race with interrupts. * uart_wait_until_sent -- that one is already called without port->mutex from set_termios and tty_set_ldisc. Should anything be protected there, it would be tx_empty. And by a spinlock. 8250 does this internally... This step is needed to fix system stalls. To not create an AB-BA lock dependency (see next patches). Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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426929f8 |
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25-Aug-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, use ASYNCB_CLOSING in uart_close We need to move port->mutex locking after wait_until_sent in uart_close (for rationale see next patches). But if we did it now, we would introduce a race between close and open. This is exactly why port->mutex is locked at the top of uart_close. To avoid the race, we add ASYNCB_CLOSING to uart_close. Like every other sane TTY driver. Thanks to tty_port_block_til_ready used in uart_open we will have this for free. Then we can move the port->mutex lock. Also note that this will make the conversion to tty_port helpers easier. They are currently handling ASYNC_CLOSING flag correctly. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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4834d028 |
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15-Aug-2011 |
Jamie Iles <jamie@jamieiles.com> |
tty: serial8250: remove UPIO_DWAPB{,32} Now that platforms can override the port IRQ handler and the only user of these UPIO modes has been converted over, kill off UPIO_DWAPB and UPIO_DWAPB32. Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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906cbe13 |
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14-Jul-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: remove tty_locked We used it really only serial and ami_serial. The rest of the callsites were BUG/WARN_ONs to check if BTM is held. Now that we pruned tty_locked from both of the real users, we can get rid of tty_lock along with __big_tty_mutex_owner. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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6a3e492b |
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14-Jul-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, remove tasklet for tty_wakeup tty_wakeup can be called from any context. So there is no need to have an extra tasklet for calling that. Hence save some space and remove the tasklet completely. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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1f33a51d |
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14-Jul-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, remove BTM from wait_until_sent During the BKL removal process, the BKL was switched to tty_lock (BTM). Now we should start pruning the BTM further. Let's start with wait_until_sent of the serial layer. This will allow us to switch to the tty port helpers and thus clean it up much. In wait_until_sent there are some uport members accessed, but neither of them is protected by BTM at the location they are set ('=>' means function call): * uport->fifosize (set in tty_ioctl => uart_ioctl => uart_set_info) * uport->type (set in add_one_port prior to tty_register_device) * uport->timeout (set usually in tty_ioctl => tty_mode_ioctl => tty_set_termios => uart_set_termios => uart_change_speed => uport->ops->set_termios => uart_update_timeout) * call to uport->ops->tx_empty() If the tx_empty hook needs some lock to protect accesses to registers, it should take &uport->lock spinlock like 8250 does. Otherwise there still might be races e.g. with ISRs. This should also fix the issue Andreas is seeing (BTM in comparison to BKL doesn't have any hidden functionality like unlocking during sleeping). Signed-off-by: Jiri Slaby <jslaby@suse.cz> References: https://lkml.org/lkml/2011/5/25/562 Cc: Alan Cox <alan@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Andreas Bombe <aeb@debian.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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0055197e |
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17-Aug-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial, document ignoring of uart->ops->startup error When a user has SYS_ADMIN capabilities and uart->ops->startup returns an error in uart_startup, we silently drop the error. We then return 0 and behave as if it didn't fail. (Not quite, since we set TTY_IO_ERROR bit and leave ASYNC_INITIALIZED bit cleared.) This all is to allow setserial to work with improperly configured or unconfigured ports. User can thus set port properties and reconfigure properly. This patch only documents this behavior. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Russel King <linux@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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c831cff2 |
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20-Apr-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial_core, remove superfluous set_task_state msleep* is guaranteed to return with TASK_RUNNING task state. And since there is no other set_task_state in the paths of uart_wait_until_sent, we need not to set_task_state to TASK_RUNNING. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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32ad3a77 |
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20-Apr-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial_core, remove invalid test tty->index (named here as line) is set up in initialize_tty_struct. The value is checked in get_tty_driver for the found driver as: if (device < base || device >= base + p->num) continue; *index = device - base; So index/line can never be more than driver->num. Hence remove this test from uart_open. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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e9a470f4 |
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18-Apr-2011 |
Govindraj.R <govindraj.raja@ti.com> |
Serial: Remove unused code. Remove stale code in serial_core layer. Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Govindraj.R <govindraj.raja@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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99edb3d1 |
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30-Mar-2011 |
Jovi Zhang <bookjovi@gmail.com> |
tty: remove invalid location line in file header remove invalid location line in each file header after location moved from driver/char to driver/tty Signed-off-by: Jovi Zhang <bookjovi@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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6f5c24ad |
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29-Mar-2011 |
Jiri Slaby <jirislaby@kernel.org> |
serial: core, remove uart_update_termios Now, uart_update_termios is empty, so it's time to remove it. We no longer need a live tty in .dtr_rts. So this should prune all the bugs where tty is zeroed in port->tty during tty_port_block_til_ready. There is one thing to note. We don't set ASYNC_NORMAL_ACTIVE now. It's because this is done already in tty_port_block_til_ready. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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303a7a11 |
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29-Mar-2011 |
Jiri Slaby <jirislaby@kernel.org> |
serial: core, do not set DTR/RTS twice on startup In .dtr_rts we do: uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS) and call uart_update_termios. It does: uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS) once again. As the only callsite of uart_update_termios is .dtr_rts, remove the uart_set_mctrl from uart_update_termios to not set it twice. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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c7d7abff |
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29-Mar-2011 |
Jiri Slaby <jirislaby@kernel.org> |
serial: core, move termios handling to uart_startup We should not fiddle with speed and cflags in .dtr_rts hook. Actually we might not have tty at that moment already. So move the console cflag copy and speed setup into uart_startup. Actually the speed setup is already there, but we need to call it unconditionally (uart_startup is called from uart_open with hw_init = 0). This means we move uart_change_speed before dtr/rts setup in .dtr_rts. But this should not matter as the setup should be called after uart_change_speed anyway. Before: After: dtr/rts setup (dtr_rts) uart_change_speed (startup) uart_change_speed (update_termios) dtr/rts setup (dtr_rts) dtr/rts setup (update_termios) dtr/rts setup (update_termios) The second setup will dismiss with the next patch. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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4fd53ef5 |
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23-Mar-2011 |
Jiri Slaby <jirislaby@kernel.org> |
TTY: serial_core, remove unused variable drivers/tty/serial/serial_core.c:1980:2: warning: Value stored to 'tty' is never read tty = port->tty; ^ ~~~~~~~~~ Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Govindraj.R <govindraj.raja@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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6caa76b7 |
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14-Feb-2011 |
Alan Cox <alan@linux.intel.com> |
tty: now phase out the ioctl file pointer for good Only oddities here are a couple of drivers that bogusly called the ldisc helpers instead of returning -ENOIOCTLCMD. Fix the bug and the rest goes away. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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20b9d177 |
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14-Feb-2011 |
Alan Cox <alan@linux.intel.com> |
tiocmset: kill the file pointer argument Doing tiocmget was such fun we should do tiocmset as well for the same reasons Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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60b33c13 |
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14-Feb-2011 |
Alan Cox <alan@linux.intel.com> |
tiocmget: kill off the passing of the struct file We don't actually need this and it causes problems for internal use of this functionality. Currently there is a single use of the FILE * pointer. That is the serial core which uses it to check tty_hung_up_p. However if that is true then IO_ERROR is also already set so the check may be removed. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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5933a161 |
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29-Jan-2011 |
Yin Kangkai <kangkai.yin@linux.intel.com> |
serial-core: reset the console speed on resume On some platforms, we need to restore the console speed on resume even it was not suspended (no_console_suspend), and on others we don't have to do that. So don't care about the "console_suspend_enabled" and unconditionally reset the console speed if it is a console. This is actually a redo of ba15ab0 (Set proper console speed on resume if console suspend is disabled) from Deepak Saxena. I also tried to investigate more to find out if this change will break others, here is what I've found out: commit 891b9dd10764352926e1e107756aa229dfa2c210 Author: Jason Wang <jason77.wang@gmail.com> serial-core: restore termios settings when resume console ports commit ca2e71aa8cfb0056ce720f3fd53f59f5fac4a3e1 Author: Jason Wang <jason77.wang@gmail.com> serial-core: skip call set_termios/console_start when no_console_suspend commit 4547be7809a3b775ce750ec7f8b5748954741523 Author: Stanislav Brabec <sbrabec@suse.cz> serial-core: resume serial hardware with no_console_suspend commit ba15ab0e8de0d4439a91342ad52d55ca9e313f3d Author: Deepak Saxena <dsaxena@laptop.org> Set proper console speed on resume if console suspend is disabled from ba15ab0, we learned that, even if the console suspend is disabled (when no_console_suspend is set), we may still need to "reset the port to the state it was in before we suspended." Then with 4547be7, this piece of code is removed. And then Jason Wang added that back in ca2e71a and 891b9dd, to fix some breakage on OMAP3EVM platform. From ca2e71a we learned that the "set_termios" things is actually needed by both console is suspended and not suspended. That's why I removed the console_suspended_enabled condition, and only call console_start() when we actually suspeneded it. I also noticed in this thread: http://marc.info/?t=129079257100004&r=1&w=2, which talked about on some platforms, UART HW will be cut power whether or not we set no_console_suspend, and then on resume it does not work quite well. I have a similar HW, and this patch fixed this issue, don't know if this patch also works on their platforms. [Update: Stanislav tested this patch on Zaurus and reported it improves the situation. Thanks.] CC: Greg KH <greg@kroah.com> CC: Deepak Saxena <dsaxena@laptop.org> CC: Jason Wang <jason77.wang@gmail.com> CC: Stanislav Brabec <sbrabec@suse.cz> CC: Daniel Drake <dsd@laptop.org> Signed-off-by: Yin Kangkai <kangkai.yin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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ab4382d2 |
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13-Jan-2011 |
Greg Kroah-Hartman <gregkh@suse.de> |
tty: move drivers/serial/ to drivers/tty/serial/ The serial drivers are really just tty drivers, so move them to drivers/tty/ to make things a bit neater overall. This is part of the tty/serial driver movement proceedure as proposed by Arnd Bergmann and approved by everyone involved a number of months ago. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl> Cc: Michael H. Warfield <mhw@wittsend.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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