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>

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>

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>

usb: gadget: u_serial: Add null pointer check in gs_start_io

If gs_close has cleared port->port.tty and gs_start_io is called
afterwards, then the function tty_wakeup will attempt to access the value
of the pointer port->port.tty which will cause a null pointer
dereference error.

To avoid this, add a null pointer check to gs_start_io before attempting
to access the value of the pointer port->port.tty.

Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
Message-ID: <20230602070009.1353946-1-khtsai@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_serial: Avoid spinlock recursion in __gs_console_push

When serial console over USB is enabled, gs_console_connect
queues gs_console_work, where it acquires the spinlock and
queues the usb request, and this request goes to gadget layer.
Now consider a situation where gadget layer prints something
to dmesg, this will eventually call gs_console_write() which
requires cons->lock. And this causes spinlock recursion. Avoid
this by excluding usb_ep_queue from the spinlock.

spin_lock_irqsave //needs cons->lock
gs_console_write
.
.
_printk
__warn_printk
dev_warn/pr_err
.
.
[USB Gadget Layer]
.
.
usb_ep_queue
gs_console_work
__gs_console_push // acquires cons->lock
process_one_work

Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
Link: https://lore.kernel.org/r/1683638872-6885-1-git-send-email-quic_prashk@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_serial: Add null pointer check in gserial_suspend

Consider a case where gserial_disconnect has already cleared
gser->ioport. And if gserial_suspend gets called afterwards,
it will lead to accessing of gser->ioport and thus causing
null pointer dereference.

Avoid this by adding a null pointer check. Added a static
spinlock to prevent gser->ioport from becoming null after
the newly added null pointer check.

Fixes: aba3a8d01d62 ("usb: gadget: u_serial: add suspend resume callbacks")
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
Link: https://lore.kernel.org/r/1683278317-11774-1-git-send-email-quic_prashk@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_serial: Add null pointer check in gserial_resume

Consider a case where gserial_disconnect has already cleared
gser->ioport. And if a wakeup interrupt triggers afterwards,
gserial_resume gets called, which will lead to accessing of
gser->ioport and thus causing null pointer dereference.Add
a null pointer check to prevent this.

Added a static spinlock to prevent gser->ioport from becoming
null after the newly added check.

Fixes: aba3a8d01d62 ("usb: gadget: u_serial: add suspend resume callbacks")
Cc: stable <stable@kernel.org>
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/1676309438-14922-1-git-send-email-quic_prashk@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: Use kstrtobool() instead of strtobool()

strtobool() is the same as kstrtobool().
However, the latter is more used within the kernel.

In order to remove strtobool() and slightly simplify kstrtox.h, switch to
the other function name.

While at it, include the corresponding header file (<linux/kstrtox.h>)

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/09bc980d8432a4b5f7d88388ec0df5b085583139.1667336095.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: add _init/__exit annotations to module init/exit funcs

Add missing _init/__exit annotations to module init/exit funcs.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Link: https://lore.kernel.org/r/20220917084413.23957-1-xiujianfeng@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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>

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>

tty: don't store semi-state into tty drivers

When a tty driver pointer is used as a return value of struct
console's device() hook, don't store a semi-state into global variable
which holds the tty driver. It could mean console::device() would return
a bogus value. This is important esp. after the next patch where we
switch from alloc_tty_driver to tty_alloc_driver. tty_alloc_driver
returns ERR_PTR in case of error and that might have unexpected results
as the code doesn't expect this.

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Felipe Balbi <balbi@kernel.org>
Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210723074317.32690-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_serial: remove WARN_ON on null port

Loading and then unloading module g_dpgp on a VM that does not
support the driver currently throws a WARN_ON message because
the port has not been initialized. Removing an unused driver
is a valid use-case and the WARN_ON kernel warning is a bit
excessive, so remove it.

Cleans up:

[27654.638698] ------------[ cut here ]------------
[27654.638705] WARNING: CPU: 6 PID: 2956336 at drivers/usb/gadget/function/u_serial.c:1201 gserial_free_line+0x7c/0x90 [u_serial]
[27654.638728] Modules linked in: g_dbgp(-) u_serial usb_f_tcm target_core_mod libcomposite udc_core vmw_vmci mcb i2c_nforce2 i2c_amd756 nfit cx8800 videobuf2_dma_sg videobuf2_memops videobuf2_v4l2 cx88xx tveeprom videobuf2_common videodev mc ccp hid_generic hid intel_ishtp cros_ec mc13xxx_core vfio_mdev mdev i915 i2c_algo_bit kvm ppdev parport zatm eni suni uPD98402 atm rio_scan binder_linux hwmon_vid video ipmi_devintf ipmi_msghandler zstd nls_utf8 decnet qrtr ns sctp ip6_udp_tunnel udp_tunnel fcrypt pcbc nhc_udp nhc_ipv6 nhc_routing nhc_mobility nhc_hop nhc_dest nhc_fragment 6lowpan ts_kmp dccp_ipv6 dccp_ipv4 dccp snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq_dummy snd_seq snd_seq_device xen_front_pgdir_shbuf binfmt_misc nls_iso8859_1 dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua intel_rapl_msr intel_rapl_common snd_hda_codec_generic ledtrig_audio snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_timer snd rapl soundcore joydev input_leds mac_hid serio_raw efi_pstore
[27654.638880] qemu_fw_cfg sch_fq_codel msr virtio_rng autofs4 btrfs blake2b_generic zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear qxl drm_ttm_helper crct10dif_pclmul ttm drm_kms_helper syscopyarea sysfillrect sysimgblt virtio_net fb_sys_fops cec net_failover rc_core ahci psmouse drm libahci lpc_ich virtio_blk failover [last unloaded: u_ether]
[27654.638949] CPU: 6 PID: 2956336 Comm: modprobe Tainted: P O 5.13.0-9-generic #9
[27654.638956] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
[27654.638969] RIP: 0010:gserial_free_line+0x7c/0x90 [u_serial]
[27654.638981] Code: 20 00 00 00 00 e8 74 1a ba c9 4c 89 e7 e8 8c fe ff ff 48 8b 3d 75 3b 00 00 44 89 f6 e8 3d 7c 69 c9 5b 41 5c 41 5d 41 5e 5d c3 <0f> 0b 4c 89 ef e8 4a 1a ba c9 5b 41 5c 41 5d 41 5e 5d c3 90 0f 1f
[27654.638986] RSP: 0018:ffffba0b81403da0 EFLAGS: 00010246
[27654.638992] RAX: 0000000000000000 RBX: ffffffffc0eaf6a0 RCX: 0000000000000000
[27654.638996] RDX: ffff8e21c0cac8c0 RSI: 0000000000000006 RDI: ffffffffc0eaf6a0
[27654.639000] RBP: ffffba0b81403dc0 R08: ffffba0b81403de0 R09: fefefefefefefeff
[27654.639003] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[27654.639006] R13: ffffffffc0eaf6a0 R14: 0000000000000000 R15: 0000000000000000
[27654.639010] FS: 00007faa1935e740(0000) GS:ffff8e223bd80000(0000) knlGS:0000000000000000
[27654.639015] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[27654.639019] CR2: 00007ffc840cd4e8 CR3: 000000000e1ac006 CR4: 0000000000370ee0
[27654.639028] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[27654.639031] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[27654.639035] Call Trace:
[27654.639044] dbgp_exit+0x1c/0xa1a [g_dbgp]
[27654.639054] __do_sys_delete_module.constprop.0+0x144/0x260
[27654.639066] ? call_rcu+0xe/0x10
[27654.639073] __x64_sys_delete_module+0x12/0x20
[27654.639081] do_syscall_64+0x61/0xb0
[27654.639092] ? exit_to_user_mode_loop+0xec/0x160
[27654.639098] ? exit_to_user_mode_prepare+0x37/0xb0
[27654.639104] ? syscall_exit_to_user_mode+0x27/0x50
[27654.639110] ? __x64_sys_close+0x12/0x40
[27654.639119] ? do_syscall_64+0x6e/0xb0
[27654.639126] ? exit_to_user_mode_prepare+0x37/0xb0
[27654.639132] ? syscall_exit_to_user_mode+0x27/0x50
[27654.639137] ? __x64_sys_newfstatat+0x1e/0x20
[27654.639146] ? do_syscall_64+0x6e/0xb0
[27654.639154] ? exc_page_fault+0x8f/0x170
[27654.639159] ? asm_exc_page_fault+0x8/0x30
[27654.639166] entry_SYSCALL_64_after_hwframe+0x44/0xae
[27654.639173] RIP: 0033:0x7faa194a4b2b
[27654.639179] Code: 73 01 c3 48 8b 0d 3d 73 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 0d 73 0c 00 f7 d8 64 89 01 48
[27654.639185] RSP: 002b:00007ffc840d0578 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[27654.639191] RAX: ffffffffffffffda RBX: 000056060f9f4e70 RCX: 00007faa194a4b2b
[27654.639194] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000056060f9f4ed8
[27654.639197] RBP: 000056060f9f4e70 R08: 0000000000000000 R09: 0000000000000000
[27654.639200] R10: 00007faa1951eac0 R11: 0000000000000206 R12: 000056060f9f4ed8
[27654.639203] R13: 0000000000000000 R14: 000056060f9f4ed8 R15: 00007ffc840d06c8
[27654.639219] ---[ end trace 8dd0ea0bb32ce94a ]---

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210701144305.110078-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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>

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>

usb: gadget: u_serial: Remove old tasklet comments

Update old comments as of 8b4c62aef6f (usb: gadget: u_serial: process RX
in workqueue instead of tasklet).

Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Link: https://lore.kernel.org/r/20210119001321.127750-1-dave@stgolabs.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_serial: use %*ph to print small buffer

Use %*ph format to print small buffer as hex string.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20201228200203.58525-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_serial: clear suspended flag when disconnecting

The commit aba3a8d01d62 ("usb: gadget: u_serial: add suspend resume
callbacks") set/cleared the suspended flag in USB bus suspend/resume
only. But, when a USB cable is disconnected in the suspend, since some
controllers will not detect USB bus resume, the suspended flag is not
cleared. After that, user cannot send any data. To fix the issue,
clears the suspended flag in the gserial_disconnect().

Fixes: aba3a8d01d62 ("usb: gadget: u_serial: add suspend resume callbacks")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Linh Phung <linh.phung.jy@renesas.com>
Tested-by: Tam Nguyen <tam.nguyen.xa@renesas.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: 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/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200707171500.GA13620@embeddedor
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: function: u_serial: Repair misdocumented function argument

Looks as though this has been an issue since the driver's
inception back in 2014.

Fixes the following W=1 kernel build warning(s):

drivers/usb/gadget/function/u_serial.c:538: warning: Function parameter or member 'port' not described in 'gs_start_io'
drivers/usb/gadget/function/u_serial.c:538: warning: Excess function parameter 'dev' description in 'gs_start_io'

Cc: Felipe Balbi <balbi@kernel.org>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Al Borchers <alborchers@steinerpoint.com>
Cc: Peter Berger <pberger@brimson.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200703174148.2749969-27-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_serial: add suspend resume callbacks

Add suspend resume callbacks to handle the case seen when the bus is
suspended by the HOST, and the device opens the port (cat /dev/ttyGS0).

Gadget controller (like DWC2) doesn't accept usb requests to be queued in
this case (when in L2 state), from the gs_open() call. Error log is printed
- configfs-gadget gadget: acm ttyGS0 can't notify serial state, -11
If the HOST resumes (opens) the bus, the port still isn't functional.

Use suspend/resume callbacks to monitor the gadget suspended state by using
'suspended' flag. In case the port gets opened (cat /dev/ttyGS0), the I/O
stream will be delayed until the bus gets resumed by the HOST.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: serial: fix Tx stall after buffer overflow

Symptom: application opens /dev/ttyGS0 and starts sending (writing) to
it while either USB cable is not connected, or nobody listens on the
other side of the cable. If driver circular buffer overflows before
connection is established, no data will be written to the USB layer
until/unless /dev/ttyGS0 is closed and re-opened again by the
application (the latter besides having no means of being notified about
the event of establishing of the connection.)

Fix: on open and/or connect, kick Tx to flush circular buffer data to
USB layer.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: u_serial: use mutex for serialising open()s

Remove home-made waiting mechanism from gs_open() and rely on
portmaster's mutex to do the job.

Note: This releases thread waiting on close() when another thread
open()s simultaneously.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_serial: diagnose missed console messages

Insert markers in console stream marking places where data
is missing. This makes the hole in the data stand out clearly
instead of glueing together unrelated messages.

Example output as seen from USB host side:

[ 0.064078] pinctrl core: registered pin 16 (UART3_RTS_N PC0) on 70000868.pinmux
[ 0.064130] pinctrl
[missed 114987 bytes]
[ 4.302299] udevd[134]: starting version 3.2.5
[ 4.306845] random: udevd: uninitialized urandom read (16 bytes read)

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_serial: allow more console gadget ports

Allow configuring more than one console using USB serial or ACM gadget.

By default, only first (ttyGS0) is a console, but this may be changed
using function's new "console" attribute.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_serial: make OBEX port not a console

Prevent OBEX serial port from ever becoming a console. Console messages
will definitely break the protocol, and since you have to instantiate
the port making it explicitly for OBEX, there is no point in allowing
console to break it by mistake.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_serial: reimplement console support

Rewrite console support to fix a few shortcomings of the old code
preventing its use with multiple ports. This removes some duplicated
code and replaces a custom kthread with simpler workqueue item.

Only port ttyGS0 gets to be a console for now.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Ladislav Michl <ladis@linux-mips.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_serial: add missing port entry locking

gserial_alloc_line() misses locking (for a release barrier) while
resetting port entry on TTY allocation failure. Fix this.

Cc: stable@vger.kernel.org
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Ladislav Michl <ladis@linux-mips.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_serial: process RX in workqueue instead of tasklet

Switch RX processing from tasklet to (delayed) work queue. This allows
receiver more room to process incoming data and prevents flood of
"ttyGS0: RX not scheduled?" messages on HS receive on slow CPU.

A side effect is 2.4MB/s zmodem transfer speed (up from 1.8MB/s)
on my test board.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: u_serial: Use kfifo instead of homemade circular buffer

The kernel FIFO implementation, kfifo, provides interfaces to manipulate
a first-in-first-out circular buffer. Use kfifo instead of the homemade
one to make the code more concise and readable.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

USB: gadget: function: Remove redundant license text

Now that the SPDX tag is in all USB 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: Oliver Neukum <oneukum@suse.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Jerry Zhang <zhangjerry@google.com>
Cc: John Keeping <john@metanate.com>
Cc: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Abdulhadi Mohamed <abdulahhadi2@gmail.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Janusz Dziedzic <januszx.dziedzic@linux.intel.com>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: add SPDX identifiers to all remaining files in drivers/usb/

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/usb/ and include/linux/usb* 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: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: serial: mark expected switch fall-through

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Addresses-Coverity-ID: 1350962
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: serial: fix oops when data rx'd after close

When the gadget serial device has no associated TTY, do not pass any
received data into the TTY layer for processing; simply drop it instead.
This prevents the TTY layer from calling back into the gadget serial
driver, which will then crash in e.g. gs_write_room() due to lack of
gadget serial device to TTY association (i.e. a NULL pointer dereference).

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: gserial: check if console kthread exists

Check for bad pointer that may result because of kthread_create failure.
This check is needed since the gserial setup callback function
(gs_console_setup()) is only freeing the info->con_buf in case of
kthread_create failure which will result into bad info->console_thread
pointer.
Without checking info->console_thread pointer validity in the
gserial_console_exit() function, before calling kthread_stop(), the
rmmod will generate Kernel Oops.

Signed-off-by: Bogdan Mirea <Bogdan-Stefan_mirea@mentor.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: serial: fix possible Oops caused by calling kthread_stop(NULL)

Add check for NULL before calling kthread_stop().

There were cases in which gserial_console_exit() was called, but the
console thread was not started. This resulted in an invalid
kthread_stop(NULL) call.

Without this, the following Oops may occur:

BUG: unable to handle kernel
NULL pointer dereference at 0000000000000018
IP: [<ffffffffb3ca1166>] kthread_stop+0x16/0x110
...
CPU: 2 PID: 853 Comm: rmmod Not tainted 4.9.0-rc5 #3
Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./Z77 Extreme3, BIOS P1.50 07/11/2013
task: ffff880419f6a100 task.stack: ffffc90002e8c000
RIP: 0010:[<ffffffffb3ca1166>] [<ffffffffb3ca1166>] kthread_stop+0x16/0x110
RSP: 0018:ffffc90002e8fdb0 EFLAGS: 00010286
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000246 RDI: 0000000000000000
RBP: ffffc90002e8fdc8 R08: 0000000000000000 R09: 0000000000000001
R10: 000000000000019d R11: 000000000000001f R12: 0000000000000000
R13: ffff88041b8d8400 R14: 0000000000000001 R15: 000055fd59f5a1e0
FS: 00007f82500be700(0000) GS:ffff88042f280000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000018 CR3: 000000041bee2000 CR4: 00000000001406e0
Stack:
0000000000000000 ffffffffc0b8e720 ffff88041b8d8400 ffffc90002e8fdf0
ffffffffc0b8bb52 ffff88041a106300 0000000000000001 ffff880419fc2ea8
ffffc90002e8fe08 ffffffffc0aed749 ffffffffc0aef600 ffffc90002e8fe20
Call Trace:
[<ffffffffc0b8bb52>] gserial_free_line+0x72/0xb0 [u_serial]
[<ffffffffc0aed749>] acm_free_instance+0x19/0x30 [usb_f_acm]
[<ffffffffc0b01b40>] usb_put_function_instance+0x20/0x30 [libcomposite]
[<ffffffffc04a603b>] gs_unbind+0x3b/0x70 [g_serial]
[<ffffffffc0b018d1>] __composite_unbind+0x61/0xb0 [libcomposite]
[<ffffffffc0b01933>] composite_unbind+0x13/0x20 [libcomposite]
[<ffffffffc08ef1ad>] usb_gadget_remove_driver+0x3d/0x90 [udc_core]
[<ffffffffc08ef26e>] usb_gadget_unregister_driver+0x6e/0xc0 [udc_core]
[<ffffffffc0aff6d2>] usb_composite_unregister+0x12/0x20 [libcomposite]
[<ffffffffc04a6268>] cleanup+0x10/0xda8 [g_serial]
[<ffffffffb3d0c0c2>] SyS_delete_module+0x192/0x270
[<ffffffffb3c032a0>] ? exit_to_usermode_loop+0x90/0xb0
[<ffffffffb4228a3b>] entry_SYSCALL_64_fastpath+0x1e/0xad
Code: 89 c6 e8 6e ff ff ff 48 89 df e8 06 bd fd ff 5b 5d c3 0f 1f 00 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 49 89 fc 53 0f 1f 44 00 00 <f0> 41 ff 44 24 18 4c 89 e7 e8 bc f1 ff ff 48 85 c0 48 89 c3 74
RIP [<ffffffffb3ca1166>] kthread_stop+0x16/0x110
RSP <ffffc90002e8fdb0>
CR2: 0000000000000018
---[ end trace 5b3336a407e1698c ]---

Signed-off-by: Felix Hädicke <felixhaedicke@web.de>
Tested-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: Convert pr_warning to pr_warn

Use the more common logging mechanism.

Miscellanea:

o Realign multiline statements
o Coalesce format

Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: Convert pr_warning to pr_warn

Use the more common logging mechanism.

Miscellanea:

o Realign multiline statements
o Coalesce format

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: Add the gserial port checking in gs_start_tx()

When usb gadget is set gadget serial function, it will be crash in below
situation.

It will clean the 'port->port_usb' pointer in gserial_disconnect() function
when usb link is inactive, but it will release lock for disabling the endpoints
in this function. Druing the lock release period, it maybe complete one request
to issue gs_write_complete()--->gs_start_tx() function, but the 'port->port_usb'
pointer had been set NULL, thus it will be crash in gs_start_tx() function.

This patch adds the 'port->port_usb' pointer checking in gs_start_tx() function
to avoid this situation.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: fix unused-but-set-variale warnings

Those are enabled with W=1 make option.

The patch leaves of some type-limits warnings which are caused by
generic macros used in a way where they produce always-false
conditions.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.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>

usb: gadget: Add the console support for usb-to-serial port

It dose not work when we want to use the usb-to-serial port based
on one usb gadget as a console. Thus this patch adds the console
initialization to support this request.

To avoid the re-entrance when transferring data with usb endpoint,
it introduces a kthread to do the IO transmission.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: gserial: Privatize close_wait

close_wait is no longer needed or provided by the tty core.
Move close_wait to struct gs_port.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: u_serial: eliminate abuse of ep->driver data

Since ep->driver_data is not used for endpoint claiming, neither for
enabled/disabled state storing, we can reduce number of places where
we read or modify it's value, as now it has no particular meaning for
function or framework logic.

In case of u_serial ep->driver_data stores pointer to struct gs_port,
which is referenced in many places in code. Code using ep->driver_data
to mark endpoint as enabled/disabled has been removed.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: serial: fix re-ordering of tx data

When a single thread is sending out data over the gadget serial port,
gs_start_tx() will be called both from the sender context and from the
write completion. Since the port lock is released before the packet is
queued, the order in which the URBs are submitted is not guaranteed.
E.g.

sending thread completion (interrupt)

gs_write()
LOCK
gs_write_complete()
LOCK (wait)
gs_start_tx()
req1 = list_entry(pool->next)
UNLOCK
LOCK (acquired)
gs_start_tx()
req2 = list_entry(pool->next)
UNLOCK
usb_ep_queue(req2)
usb_ep_queue(req1)

I.e., req2 is submitted before req1 but it contains the data that
comes after req1.

To reproduce, use SMP with sending thread and completion pinned to
different CPUs, or use PREEMPT_RT, and add the following delay just
before the call to usb_ep_queue():

if (port->write_started > 0 && !list_empty(pool))
udelay(1000);

To work around this problem, make sure that only one thread is running
through the gs_start_tx() loop with an extra flag write_busy. Since
gs_start_tx() is always called with the port lock held, no further
synchronisation is needed. The original caller will continue through
the loop when the request was successfully submitted.

Signed-off-by: Philip Oberstaller <Philip.Oberstaller@septentrio.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: serial: %pf is only for function pointers

Use %ps for actual addresses, otherwise you'll get bad output
on arches like ppc64 where %pf expects a function descriptor
(which is not what __builtin_return_address returns).

Reviewed-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: linux-usb@vger.kernel.org
CC: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: serial: remove PREFIX macro

Remove the ttyGS PREFIX macro from u_serial.c and replace all occurences with
the hardcoded ttyGS string.

This macro was mostly used in a few debug/warning messages and a lot of
hardcoded ttyGS existed beneath. It may have been used for renaming the
tty, but if done so most debug messages would have ignored this.

Due to the fact the usage of this PREFIX in all debug calls would have
resulted in a hard to read/grep code it is removed completely.

Signed-off-by: Richard Leitner <richard.leitner@skidata.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: Gadget directory cleanup - group usb functions

The drivers/usb/gadget directory contains many files.
Files which are related can be distributed into separate directories.
This patch moves the USB functions implementations into a separate directory.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>