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6aeb8850 |
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05-Mar-2024 |
Nícolas F. R. A. Prado <nfraprado@collabora.com> |
device: core: Log warning for devices pending deferred probe on timeout Once the deferred probe timeout has elapsed it is very likely that the devices that are still deferring probe won't ever be probed. Therefore log the defer probe pending reason at the warning level instead to bring attention to the issue. Signed-off-by: "Nícolas F. R. A. Prado" <nfraprado@collabora.com> Link: https://lore.kernel.org/r/20240305-device-probe-error-v1-3-a06d8722bf19@collabora.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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448af2d2 |
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05-Mar-2024 |
Nícolas F. R. A. Prado <nfraprado@collabora.com> |
driver: core: Use dev_* instead of pr_* so device metadata is added Use the dev_* instead of the pr_* functions to log the status of device probe so that the log message gets the device metadata attached to it. Signed-off-by: "Nícolas F. R. A. Prado" <nfraprado@collabora.com> Link: https://lore.kernel.org/r/20240305-device-probe-error-v1-2-a06d8722bf19@collabora.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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32de4b4f |
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05-Mar-2024 |
Nícolas F. R. A. Prado <nfraprado@collabora.com> |
driver: core: Log probe failure as error and with device metadata Drivers can return -ENODEV or -ENXIO from their probe to reject a device match, and return -EPROBE_DEFER if probe should be retried. Any other error code is not expected during normal behavior and indicates an issue occurred, so it should be logged at the error level. Also make use of the device variant, dev_err(), so that the device metadata is attached to the log message. Signed-off-by: "Nícolas F. R. A. Prado" <nfraprado@collabora.com> Link: https://lore.kernel.org/r/20240305-device-probe-error-v1-1-a06d8722bf19@collabora.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
7c41da58 |
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22-Nov-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
driver core: Emit reason for pending deferred probe Ending a boot log with platform 3f202000.mmc: deferred probe pending is already a nice hint about the problem. Sometimes there is a more detailed error indicator available, add that to the output. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20231122093332.274145-2-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2e84dc37 |
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17-Oct-2023 |
Saravana Kannan <saravanak@google.com> |
driver core: Release all resources during unbind before updating device links This commit fixes a bug in commit 9ed9895370ae ("driver core: Functional dependencies tracking support") where the device link status was incorrectly updated in the driver unbind path before all the device's resources were released. Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support") Cc: stable <stable@kernel.org> Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Closes: https://lore.kernel.org/all/20231014161721.f4iqyroddkcyoefo@pengutronix.de/ Signed-off-by: Saravana Kannan <saravanak@google.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Yang Yingliang <yangyingliang@huawei.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Mark Brown <broonie@kernel.org> Cc: Matti Vaittinen <mazziesaccount@gmail.com> Cc: James Clark <james.clark@arm.com> Acked-by: "Rafael J. Wysocki" <rafael@kernel.org> Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20231018013851.3303928-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
f429378a |
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24-Jul-2023 |
Jason Gunthorpe <jgg@ziepe.ca> |
driver core: Call dma_cleanup() on the test_remove path When test_remove is enabled really_probe() does not properly pair dma_configure() with dma_remove(), it will end up calling dma_configure() twice. This corrupts the owner_cnt and renders the group unusable with VFIO/etc. Add the missing cleanup before going back to re_probe. Fixes: 25f3bcfc54bc ("driver core: Add dma_cleanup callback in bus_type") Reported-by: Zenghui Yu <yuzenghui@huawei.com> Tested-by: Zenghui Yu <yuzenghui@huawei.com> Closes: https://lore.kernel.org/all/6472f254-c3c4-8610-4a37-8d9dfdd54ce8@huawei.com/ Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/0-v2-4deed94e283e+40948-really_probe_dma_cleanup_jgg@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
aa5f6ed8 |
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31-May-2023 |
Christoph Hellwig <hch@lst.de> |
driver core: return bool from driver_probe_done bool is the most sensible return value for a yes/no return. Also add __init as this funtion is only called from the early boot code. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20230531125535.676098-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
e2f06aa8 |
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12-Apr-2023 |
Stephen Boyd <swboyd@chromium.org> |
driver core: Don't require dynamic_debug for initcall_debug probe timing Don't require the use of dynamic debug (or modification of the kernel to add a #define DEBUG to the top of this file) to get the printk message about driver probe timing. This printk is only emitted when initcall_debug is enabled on the kernel commandline, and it isn't immediately obvious that you have to do something else to debug boot timing issues related to driver probe. Add a comment too so it doesn't get converted back to pr_debug(). Fixes: eb7fbc9fb118 ("driver core: Add missing '\n' in log messages") Cc: stable <stable@kernel.org> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Brian Norris <briannorris@chromium.org> Reviewed-by: Brian Norris <briannorris@chromium.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20230412225842.3196599-1-swboyd@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
f8fb5766 |
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03-Mar-2023 |
Saravana Kannan <saravanak@google.com> |
driver core: Make state_synced device attribute writeable If the file is written to and sync_state() hasn't been called for the device yet, then call sync_state() for the device independent of the state of its consumers. This is useful for supplier devices that have one or more consumers that don't have a driver but the consumers are in a state that don't use the resources supplied by the supplier device. This gives finer grained control than using the fw_devlink.sync_state=timeout kernel commandline parameter. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20230304005355.746421-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
ffbe08a8 |
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03-Mar-2023 |
Saravana Kannan <saravanak@google.com> |
driver core: Add fw_devlink.sync_state command line param When all devices that could probe have finished probing (based on deferred_probe_timeout configuration or late_initcall() when !CONFIG_MODULES), this parameter controls what to do with devices that haven't yet received their sync_state() calls. fw_devlink.sync_state=strict is the default and the driver core will continue waiting on all consumers of a device to probe successfully before sync_state() is called for the device. This is the default behavior since calling sync_state() on a device when all its consumers haven't probed could make some systems unusable/unstable. When this option is selected, we also print the list of devices that haven't had sync_state() called on them by the time all devices the could probe have finished probing. fw_devlink.sync_state=timeout will cause the driver core to give up waiting on consumers and call sync_state() on any devices that haven't yet received their sync_state() calls. This option is provided for systems that won't become unusable/unstable as they might be able to save power (depends on state of hardware before kernel starts) if all devices get their sync_state(). Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20230304005355.746421-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
36c893d3 |
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02-Feb-2023 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
drivers: base: dd: fix memory leak with using debugfs_lookup() When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230202141621.2296458-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
ed9f9181 |
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11-Jan-2023 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
driver core: bus: move bus notifier logic into bus.c The logic to touch the bus notifier was open-coded in numberous places in the driver core. Clean that up by creating a local bus_notify() function and have everyone call this function instead, making the reading of the caller code simpler and easier to maintain over time. Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20230111092331.3946745-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
504fa212 |
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27-Dec-2022 |
Javier Martinez Canillas <javierm@redhat.com> |
driver core: Make driver_deferred_probe_timeout a static variable It is not used outside of its compilation unit, so there's no need to export this variable. Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Andrew Halaney <ahalaney@redhat.com> Acked-by: John Stultz <jstultz@google.com> Link: https://lore.kernel.org/r/20221227232152.3094584-1-javierm@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
27c0d217 |
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20-Sep-2022 |
Isaac J. Manjarres <isaacmanjarres@google.com> |
driver core: Fix bus_type.match() error handling in __driver_attach() When a driver registers with a bus, it will attempt to match with every device on the bus through the __driver_attach() function. Currently, if the bus_type.match() function encounters an error that is not -EPROBE_DEFER, __driver_attach() will return a negative error code, which causes the driver registration logic to stop trying to match with the remaining devices on the bus. This behavior is not correct; a failure while matching a driver to a device does not mean that the driver won't be able to match and bind with other devices on the bus. Update the logic in __driver_attach() to reflect this. Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()") Cc: stable@vger.kernel.org Cc: Saravana Kannan <saravanak@google.com> Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com> Link: https://lore.kernel.org/r/20220921001414.4046492-1-isaacmanjarres@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
189a87f8 |
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30-Oct-2022 |
Christoph Hellwig <hch@lst.de> |
driver core: mark driver_allows_async_probing static driver_allows_async_probing is only used in drivers/base/dd.c, so mark it static and remove the declaration in drivers/base/base.h. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221030092255.872280-1-hch@lst.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
07b7b883 |
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18-Aug-2022 |
Wolfram Sang <wsa+renesas@sang-engineering.com> |
driver_core: 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/ Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20220818205956.6528-1-wsa+renesas@sang-engineering.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
25e9fbf0 |
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17-Aug-2022 |
Isaac J. Manjarres <isaacmanjarres@google.com> |
driver core: Don't probe devices after bus_type.match() probe deferral Both __device_attach_driver() and __driver_attach() check the return code of the bus_type.match() function to see if the device needs to be added to the deferred probe list. After adding the device to the list, the logic attempts to bind the device to the driver anyway, as if the device had matched with the driver, which is not correct. If __device_attach_driver() detects that the device in question is not ready to match with a driver on the bus, then it doesn't make sense for the device to attempt to bind with the current driver or continue attempting to match with any of the other drivers on the bus. So, update the logic in __device_attach_driver() to reflect this. If __driver_attach() detects that a driver tried to match with a device that is not ready to match yet, then the driver should not attempt to bind with the device. However, the driver can still attempt to match and bind with other devices on the bus, as drivers can be bound to multiple devices. So, update the logic in __driver_attach() to reflect this. Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()") Cc: stable@vger.kernel.org Cc: Saravana Kannan <saravanak@google.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Saravana Kannan <saravanak@google.com> Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com> Link: https://lore.kernel.org/r/20220817184026.3468620-1-isaacmanjarres@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
13a8e0f6 |
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19-Aug-2022 |
Saravana Kannan <saravanak@google.com> |
Revert "driver core: Delete driver_deferred_probe_check_state()" This reverts commit 9cbffc7a59561be950ecc675d19a3d2b45202b2b. There are a few more issues to fix that have been reported in the thread for the original series [1]. We'll need to fix those before this will work. So, revert it for now. [1] - https://lore.kernel.org/lkml/20220601070707.3946847-1-saravanak@google.com/ Fixes: 9cbffc7a5956 ("driver core: Delete driver_deferred_probe_check_state()") Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Peng Fan <peng.fan@nxp.com> Tested-by: Douglas Anderson <dianders@chromium.org> Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220819221616.2107893-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
70fe7583 |
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22-Jun-2022 |
Zhang Wensheng <zhangwensheng5@huawei.com> |
driver core: fix potential deadlock in __driver_attach In __driver_attach function, There are also AA deadlock problem, like the commit b232b02bf3c2 ("driver core: fix deadlock in __device_attach"). stack like commit b232b02bf3c2 ("driver core: fix deadlock in __device_attach"). list below: In __driver_attach function, The lock holding logic is as follows: ... __driver_attach if (driver_allows_async_probing(drv)) device_lock(dev) // get lock dev async_schedule_dev(__driver_attach_async_helper, dev); // func async_schedule_node async_schedule_node_domain(func) entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC); /* when fail or work limit, sync to execute func, but __driver_attach_async_helper will get lock dev as will, which will lead to A-A deadlock. */ if (!entry || atomic_read(&entry_count) > MAX_WORK) { func; else queue_work_node(node, system_unbound_wq, &entry->work) device_unlock(dev) As above show, when it is allowed to do async probes, because of out of memory or work limit, async work is not be allowed, to do sync execute instead. it will lead to A-A deadlock because of __driver_attach_async_helper getting lock dev. Reproduce: and it can be reproduce by make the condition (if (!entry || atomic_read(&entry_count) > MAX_WORK)) untenable, like below: [ 370.785650] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 370.787154] task:swapper/0 state:D stack: 0 pid: 1 ppid: 0 flags:0x00004000 [ 370.788865] Call Trace: [ 370.789374] <TASK> [ 370.789841] __schedule+0x482/0x1050 [ 370.790613] schedule+0x92/0x1a0 [ 370.791290] schedule_preempt_disabled+0x2c/0x50 [ 370.792256] __mutex_lock.isra.0+0x757/0xec0 [ 370.793158] __mutex_lock_slowpath+0x1f/0x30 [ 370.794079] mutex_lock+0x50/0x60 [ 370.794795] __device_driver_lock+0x2f/0x70 [ 370.795677] ? driver_probe_device+0xd0/0xd0 [ 370.796576] __driver_attach_async_helper+0x1d/0xd0 [ 370.797318] ? driver_probe_device+0xd0/0xd0 [ 370.797957] async_schedule_node_domain+0xa5/0xc0 [ 370.798652] async_schedule_node+0x19/0x30 [ 370.799243] __driver_attach+0x246/0x290 [ 370.799828] ? driver_allows_async_probing+0xa0/0xa0 [ 370.800548] bus_for_each_dev+0x9d/0x130 [ 370.801132] driver_attach+0x22/0x30 [ 370.801666] bus_add_driver+0x290/0x340 [ 370.802246] driver_register+0x88/0x140 [ 370.802817] ? virtio_scsi_init+0x116/0x116 [ 370.803425] scsi_register_driver+0x1a/0x30 [ 370.804057] init_sd+0x184/0x226 [ 370.804533] do_one_initcall+0x71/0x3a0 [ 370.805107] kernel_init_freeable+0x39a/0x43a [ 370.805759] ? rest_init+0x150/0x150 [ 370.806283] kernel_init+0x26/0x230 [ 370.806799] ret_from_fork+0x1f/0x30 To fix the deadlock, move the async_schedule_dev outside device_lock, as we can see, in async_schedule_node_domain, the parameter of queue_work_node is system_unbound_wq, so it can accept concurrent operations. which will also not change the code logic, and will not lead to deadlock. Fixes: ef0ff68351be ("driver core: Probe devices asynchronously instead of the driver") Signed-off-by: Zhang Wensheng <zhangwensheng5@huawei.com> Link: https://lore.kernel.org/r/20220622074327.497102-1-zhangwensheng5@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
9cbffc7a |
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01-Jun-2022 |
Saravana Kannan <saravanak@google.com> |
driver core: Delete driver_deferred_probe_check_state() The function is no longer used. So delete it. Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220601070707.3946847-10-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f516d01b |
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01-Jun-2022 |
Saravana Kannan <saravanak@google.com> |
Revert "driver core: Set default deferred_probe_timeout back to 0." This reverts commit 11f7e7ef553b6b93ac1aa74a3c2011b9cc8aeb61. Let's take another shot at getting deferred_probe_timeout=10 to work. Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220601070707.3946847-7-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
2f8c3ae8 |
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01-Jun-2022 |
Saravana Kannan <saravanak@google.com> |
driver core: Add wait_for_init_devices_probe helper function Some devices might need to be probed and bound successfully before the kernel boot sequence can finish and move on to init/userspace. For example, a network interface might need to be bound to be able to mount a NFS rootfs. With fw_devlink=on by default, some of these devices might be blocked from probing because they are waiting on a optional supplier that doesn't have a driver. While fw_devlink will eventually identify such devices and unblock the probing automatically, it might be too late by the time it unblocks the probing of devices. For example, the IP4 autoconfig might timeout before fw_devlink unblocks probing of the network interface. This function is available to temporarily try and probe all devices that have a driver even if some of their suppliers haven't been added or don't have drivers. The drivers can then decide which of the suppliers are optional vs mandatory and probe the device if possible. By the time this function returns, all such "best effort" probes are guaranteed to be completed. If a device successfully probes in this mode, we delete all fw_devlink discovered dependencies of that device where the supplier hasn't yet probed successfully because they have to be optional dependencies. This also means that some devices that aren't needed for init and could have waited for their optional supplier to probe (when the supplier's module is loaded later on) would end up probing prematurely with limited functionality. So call this function only when boot would fail without it. Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220601070707.3946847-5-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
9be4cbd0 |
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03-Jun-2022 |
Saravana Kannan <saravanak@google.com> |
driver core: Set default deferred_probe_timeout back to 0. Since we had to effectively reverted commit 35a672363ab3 ("driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires") in an earlier patch, a non-zero deferred_probe_timeout will break NFS rootfs mounting [1] again. So, set the default back to zero until we can fix that. [1] - https://lore.kernel.org/lkml/TYAPR01MB45443DF63B9EF29054F7C41FD8C60@TYAPR01MB4544.jpnprd01.prod.outlook.com/ Fixes: 2b28a1a84a0e ("driver core: Extend deferred probe timeout on driver registration") Cc: Mark Brown <broonie@kernel.org> Cc: Rob Herring <robh@kernel.org> Reported-by: Nathan Chancellor <nathan@kernel.org> Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220526034609.480766-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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5ee76c25 |
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03-Jun-2022 |
Saravana Kannan <saravanak@google.com> |
driver core: Fix wait_for_device_probe() & deferred_probe_timeout interaction Mounting NFS rootfs was timing out when deferred_probe_timeout was non-zero [1]. This was because ip_auto_config() initcall times out waiting for the network interfaces to show up when deferred_probe_timeout was non-zero. While ip_auto_config() calls wait_for_device_probe() to make sure any currently running deferred probe work or asynchronous probe finishes, that wasn't sufficient to account for devices being deferred until deferred_probe_timeout. Commit 35a672363ab3 ("driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires") tried to fix that by making sure wait_for_device_probe() waits for deferred_probe_timeout to expire before returning. However, if wait_for_device_probe() is called from the kernel_init() context: - Before deferred_probe_initcall() [2], it causes the boot process to hang due to a deadlock. - After deferred_probe_initcall() [3], it blocks kernel_init() from continuing till deferred_probe_timeout expires and beats the point of deferred_probe_timeout that's trying to wait for userspace to load modules. Neither of this is good. So revert the changes to wait_for_device_probe(). [1] - https://lore.kernel.org/lkml/TYAPR01MB45443DF63B9EF29054F7C41FD8C60@TYAPR01MB4544.jpnprd01.prod.outlook.com/ [2] - https://lore.kernel.org/lkml/YowHNo4sBjr9ijZr@dev-arch.thelio-3990X/ [3] - https://lore.kernel.org/lkml/Yo3WvGnNk3LvLb7R@linutronix.de/ Fixes: 35a672363ab3 ("driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires") Cc: John Stultz <jstultz@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Basil Eljuse <Basil.Eljuse@arm.com> Cc: Ferry Toth <fntoth@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: linux-pm@vger.kernel.org Reported-by: Nathan Chancellor <nathan@kernel.org> Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: John Stultz <jstultz@google.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220526034609.480766-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
b232b02b |
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18-May-2022 |
Zhang Wensheng <zhangwensheng5@huawei.com> |
driver core: fix deadlock in __device_attach In __device_attach function, The lock holding logic is as follows: ... __device_attach device_lock(dev) // get lock dev async_schedule_dev(__device_attach_async_helper, dev); // func async_schedule_node async_schedule_node_domain(func) entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC); /* when fail or work limit, sync to execute func, but __device_attach_async_helper will get lock dev as well, which will lead to A-A deadlock. */ if (!entry || atomic_read(&entry_count) > MAX_WORK) { func; else queue_work_node(node, system_unbound_wq, &entry->work) device_unlock(dev) As shown above, when it is allowed to do async probes, because of out of memory or work limit, async work is not allowed, to do sync execute instead. it will lead to A-A deadlock because of __device_attach_async_helper getting lock dev. To fix the deadlock, move the async_schedule_dev outside device_lock, as we can see, in async_schedule_node_domain, the parameter of queue_work_node is system_unbound_wq, so it can accept concurrent operations. which will also not change the code logic, and will not lead to deadlock. Fixes: 765230b5f084 ("driver-core: add asynchronous probing support for drivers") Signed-off-by: Zhang Wensheng <zhangwensheng5@huawei.com> Link: https://lore.kernel.org/r/20220518074516.1225580-1-zhangwensheng5@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2b28a1a8 |
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29-Apr-2022 |
Saravana Kannan <saravanak@google.com> |
driver core: Extend deferred probe timeout on driver registration The deferred probe timer that's used for this currently starts at late_initcall and runs for driver_deferred_probe_timeout seconds. The assumption being that all available drivers would be loaded and registered before the timer expires. This means, the driver_deferred_probe_timeout has to be pretty large for it to cover the worst case. But if we set the default value for it to cover the worst case, it would significantly slow down the average case. For this reason, the default value is set to 0. Also, with CONFIG_MODULES=y and the current default values of driver_deferred_probe_timeout=0 and fw_devlink=on, devices with missing drivers will cause their consumer devices to always defer their probes. This is because device links created by fw_devlink defer the probe even before the consumer driver's probe() is called. Instead of a fixed timeout, if we extend an unexpired deferred probe timer on every successful driver registration, with the expectation more modules would be loaded in the near future, then the default value of driver_deferred_probe_timeout only needs to be as long as the worst case time difference between two consecutive module loads. So let's implement that and set the default value to 10 seconds when CONFIG_MODULES=y. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Rob Herring <robh@kernel.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Will Deacon <will@kernel.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Kevin Hilman <khilman@kernel.org> Cc: Thierry Reding <treding@nvidia.com> Cc: Mark Brown <broonie@kernel.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: Paul Kocialkowski <paul.kocialkowski@bootlin.com> Cc: linux-gpio@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: iommu@lists.linux-foundation.org Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220429220933.1350374-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f79f662e |
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03-May-2022 |
Saravana Kannan <saravanak@google.com> |
driver core: Add "*" wildcard support to driver_async_probe cmdline param There's currently no way to use driver_async_probe kernel cmdline param to enable default async probe for all drivers. So, add support for "*" to match with all driver names. When "*" is used, all other drivers listed in driver_async_probe are drivers that will NOT match the "*". For example: * driver_async_probe=drvA,drvB,drvC drvA, drvB and drvC do asynchronous probing. * driver_async_probe=* All drivers do asynchronous probing except those that have set PROBE_FORCE_SYNCHRONOUS flag. * driver_async_probe=*,drvA,drvB,drvC All drivers do asynchronous probing except drvA, drvB, drvC and those that have set PROBE_FORCE_SYNCHRONOUS flag. Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Feng Tang <feng.tang@intel.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20220504005344.117803-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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84e7c678 |
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16-Mar-2022 |
Mark-PK Tsai <mark-pk.tsai@mediatek.com> |
driver core: Prevent overriding async driver of a device before it probe When there are 2 matched drivers for a device using async probe mechanism, the dev->p->async_driver might be overridden by the last attached driver. So just skip the later one if the previous matched driver was not handled by async thread yet. Below is my use case which having this problem. Make both driver mmcblk and mmc_test allow async probe, the dev->p->async_driver will be overridden by the later driver mmc_test and bind to the device then claim it for testing. When it happen, mmcblk will never do probe again. Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Link: https://lore.kernel.org/r/20220316074328.1801-1-mark-pk.tsai@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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4c32174a |
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16-Apr-2022 |
Bagas Sanjaya <bagasdotme@gmail.com> |
Documentation: dd: Use ReST lists for return values of driver_deferred_probe_check_state() Sphinx reported build warnings mentioning drivers/base/dd.c: </path/to/linux>/Documentation/driver-api/infrastructure:35: ./drivers/base/dd.c:280: WARNING: Unexpected indentation. </path/to/linux>/Documentation/driver-api/infrastructure:35: ./drivers/base/dd.c:281: WARNING: Block quote ends without a blank line; unexpected unindent. The warnings above is due to syntax error in the "Return" section of driver_deferred_probe_check_state() which messed up with desired line breaks. Fix the issue by using ReST lists syntax. Fixes: c8c43cee29f6ca ("driver core: Fix driver_deferred_probe_check_state() logic") Cc: linux-pm@vger.kernel.org Cc: stable@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Thierry Reding <treding@nvidia.com> Cc: Mark Brown <broonie@kernel.org> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Todd Kjos <tkjos@google.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Kevin Hilman <khilman@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Rob Herring <robh@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20220416071137.19512-1-bagasdotme@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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25f3bcfc |
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17-Apr-2022 |
Lu Baolu <baolu.lu@linux.intel.com> |
driver core: Add dma_cleanup callback in bus_type The bus_type structure defines dma_configure() callback for bus drivers to configure DMA on the devices. This adds the paired dma_cleanup() callback and calls it during driver unbinding so that bus drivers can do some cleanup work. One use case for this paired DMA callbacks is for the bus driver to check for DMA ownership conflicts during driver binding, where multiple devices belonging to a same IOMMU group (the minimum granularity of isolation and protection) may be assigned to kernel drivers or user space respectively. Without this change, for example, the vfio driver has to listen to a bus BOUND_DRIVER event and then BUG_ON() in case of dma ownership conflict. This leads to bad user experience since careless driver binding operation may crash the system if the admin overlooks the group restriction. Aside from bad design, this leads to a security problem as a root user, even with lockdown=integrity, can force the kernel to BUG. With this change, the bus driver could check and set the DMA ownership in driver binding process and fail on ownership conflicts. The DMA ownership should be released during driver unbinding. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20220418005000.897664-3-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
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74befa44 |
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07-Apr-2022 |
Vladimir Oltean <vladimir.oltean@nxp.com> |
net: mdio: don't defer probe forever if PHY IRQ provider is missing When a driver for an interrupt controller is missing, of_irq_get() returns -EPROBE_DEFER ad infinitum, causing fwnode_mdiobus_phy_device_register(), and ultimately, the entire of_mdiobus_register() call, to fail. In turn, any phy_connect() call towards a PHY on this MDIO bus will also fail. This is not what is expected to happen, because the PHY library falls back to poll mode when of_irq_get() returns a hard error code, and the MDIO bus, PHY and attached Ethernet controller work fine, albeit suboptimally, when the PHY library polls for link status. However, -EPROBE_DEFER has special handling given the assumption that at some point probe deferral will stop, and the driver for the supplier will kick in and create the IRQ domain. Reasons for which the interrupt controller may be missing: - It is not yet written. This may happen if a more recent DT blob (with an interrupt-parent for the PHY) is used to boot an old kernel where the driver didn't exist, and that kernel worked with the vintage-correct DT blob using poll mode. - It is compiled out. Behavior is the same as above. - It is compiled as a module. The kernel will wait for a number of seconds specified in the "deferred_probe_timeout" boot parameter for user space to load the required module. The current default is 0, which times out at the end of initcalls. It is possible that this might cause regressions unless users adjust this boot parameter. The proposed solution is to use the driver_deferred_probe_check_state() helper function provided by the driver core, which gives up after some -EPROBE_DEFER attempts, taking "deferred_probe_timeout" into consideration. The return code is changed from -EPROBE_DEFER into -ENODEV or -ETIMEDOUT, depending on whether the kernel is compiled with support for modules or not. Fixes: 66bdede495c7 ("of_mdio: Fix broken PHY IRQ in case of probe deferral") Suggested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20220407165538.4084809-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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90158138 |
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09-Mar-2022 |
lizhe <sensor1010@163.com> |
drivers/base/dd.c : Remove the initial value of the global variable The global variable driver_deferred_probe_enable has a default value of false and does not need to be initialized to false. Signed-off-by: lizhe <sensor1010@163.com> Link: https://lore.kernel.org/r/20220309135418.31101-1-sensor1010@163.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f2aad547 |
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28-Feb-2022 |
Randy Dunlap <rdunlap@infradead.org> |
driver core: dd: fix return value of __setup handler When "driver_async_probe=nulltty" is used on the kernel boot command line, it causes an Unknown parameter message and the string is added to init's environment strings, polluting them. Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc6 driver_async_probe=nulltty", will be passed to user space. Run /sbin/init as init process with arguments: /sbin/init with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc6 driver_async_probe=nulltty Change the return value of the __setup function to 1 to indicate that the __setup option has been handled. Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Fixes: 1ea61b68d0f8 ("async: Add cmdline option to specify drivers to be async probed") Cc: Feng Tang <feng.tang@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru> Reviewed-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20220301041829.15137-1-rdunlap@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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4b775aaf |
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23-Feb-2022 |
Rob Herring <robh@kernel.org> |
driver core: Refactor sysfs and drv/bus remove hooks There are 3 copies of the same device sysfs cleanup and drv/bus remove() hooks used for probe failure, testing re-probing, and device unbinding. Let's refactor the code to its own function. Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20220223225257.1681968-3-robh@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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9ad30721 |
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23-Feb-2022 |
Rob Herring <robh@kernel.org> |
driver core: Refactor multiple copies of device cleanup There are 3 copies of the same device cleanup code used for probe failure, testing re-probing, and device unbinding. Changes to this code often miss at least one of the copies of the code. See commits d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed") and d8f7a5484f21 ("driver core: Free DMA range map when device is released") for example. Let's refactor the code to its own function. Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20220223225257.1681968-2-robh@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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b4ae8c2f |
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12-Feb-2022 |
Tom Rix <trix@redhat.com> |
driver core: cleanup double words comments Remove the second 'are' and 'the'. Signed-off-by: Tom Rix <trix@redhat.com> Link: https://lore.kernel.org/r/20220212143233.2648872-1-trix@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d8f7a548 |
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16-Feb-2022 |
Mårten Lindahl <marten.lindahl@axis.com> |
driver core: Free DMA range map when device is released When unbinding/binding a driver with DMA mapped memory, the DMA map is not freed before the driver is reloaded. This leads to a memory leak when the DMA map is overwritten when reprobing the driver. This can be reproduced with a platform driver having a dma-range: dummy { ... #address-cells = <0x2>; #size-cells = <0x2>; ranges; dma-ranges = <...>; ... }; and then unbinding/binding it: ~# echo soc:dummy >/sys/bus/platform/drivers/<driver>/unbind DMA map object 0xffffff800b0ae540 still being held by &pdev->dev ~# echo soc:dummy >/sys/bus/platform/drivers/<driver>/bind ~# echo scan > /sys/kernel/debug/kmemleak ~# cat /sys/kernel/debug/kmemleak unreferenced object 0xffffff800b0ae540 (size 64): comm "sh", pid 833, jiffies 4295174550 (age 2535.352s) hex dump (first 32 bytes): 00 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 80 00 00 00 00 00 00 00 80 00 00 00 00 ................ backtrace: [<ffffffefd1694708>] create_object.isra.0+0x108/0x344 [<ffffffefd1d1a850>] kmemleak_alloc+0x8c/0xd0 [<ffffffefd167e2d0>] __kmalloc+0x440/0x6f0 [<ffffffefd1a960a4>] of_dma_get_range+0x124/0x220 [<ffffffefd1a8ce90>] of_dma_configure_id+0x40/0x2d0 [<ffffffefd198b68c>] platform_dma_configure+0x5c/0xa4 [<ffffffefd198846c>] really_probe+0x8c/0x514 [<ffffffefd1988990>] __driver_probe_device+0x9c/0x19c [<ffffffefd1988cd8>] device_driver_attach+0x54/0xbc [<ffffffefd1986634>] bind_store+0xc4/0x120 [<ffffffefd19856e0>] drv_attr_store+0x30/0x44 [<ffffffefd173c9b0>] sysfs_kf_write+0x50/0x60 [<ffffffefd173c1c4>] kernfs_fop_write_iter+0x124/0x1b4 [<ffffffefd16a013c>] new_sync_write+0xdc/0x160 [<ffffffefd16a256c>] vfs_write+0x23c/0x2a0 [<ffffffefd16a2758>] ksys_write+0x64/0xec To prevent this we should free the dma_range_map when the device is released. Fixes: e0d072782c73 ("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset") Cc: stable <stable@vger.kernel.org> Suggested-by: Rob Herring <robh@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com> Link: https://lore.kernel.org/r/20220216094128.4025861-1-marten.lindahl@axis.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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00eb74ea |
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30-Dec-2021 |
Lu Baolu <baolu.lu@linux.intel.com> |
driver core: Make bus notifiers in right order in really_probe() If a driver cannot be bound to a device, the correct bus notifier order should be: - BUS_NOTIFY_BIND_DRIVER: driver is about to be bound - BUS_NOTIFY_DRIVER_NOT_BOUND: driver failed to be bound or no notifier if the failure happens before the actual binding. The really_probe() notifies a BUS_NOTIFY_DRIVER_NOT_BOUND event without a BUS_NOTIFY_BIND_DRIVER if .dma_configure() returns failure. This change makes the notifiers in order. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20211231033901.2168664-3-baolu.lu@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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885e5025 |
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30-Dec-2021 |
Lu Baolu <baolu.lu@linux.intel.com> |
driver core: Move driver_sysfs_remove() after driver_sysfs_add() The driver_sysfs_remove() should be called after driver_sysfs_add() in really_probe(). The out-of-order driver_sysfs_remove() tries to remove some nonexistent nodes under the device and driver sysfs nodes. This is allowed, hence this change doesn't fix any problem, just a cleanup. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20211231033901.2168664-2-baolu.lu@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f04948de |
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07-Jul-2021 |
Zhen Lei <thunder.leizhen@huawei.com> |
driver core: Fix error return code in really_probe() In the case of error handling, the error code returned by the subfunction should be propagated instead of 0. Fixes: 1901fb2604fb ("Driver core: fix "driver" symlink timing") Fixes: 23b6904442d0 ("driver core: add dev_groups to all drivers") Fixes: 8fd456ec0cf0 ("driver core: Add state_synced sysfs file for devices that support it") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Link: https://lore.kernel.org/r/20210707074301.2722-1-thunder.leizhen@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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4d1014c1 |
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27-Jul-2021 |
Filip Schauer <filip@mg6.at> |
drivers core: Fix oops when driver probe fails dma_range_map is freed to early, which might cause an oops when a driver probe fails. Call trace: is_free_buddy_page+0xe4/0x1d4 __free_pages+0x2c/0x88 dma_free_contiguous+0x64/0x80 dma_direct_free+0x38/0xb4 dma_free_attrs+0x88/0xa0 dmam_release+0x28/0x34 release_nodes+0x78/0x8c devres_release_all+0xa8/0x110 really_probe+0x118/0x2d0 __driver_probe_device+0xc8/0xe0 driver_probe_device+0x54/0xec __driver_attach+0xe0/0xf0 bus_for_each_dev+0x7c/0xc8 driver_attach+0x30/0x3c bus_add_driver+0x17c/0x1c4 driver_register+0xc0/0xf8 __platform_driver_register+0x34/0x40 ... This issue is introduced by commit d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed"). It frees dma_range_map before the call to devres_release_all, which is too early. The solution is to free dma_range_map only after devres_release_all. Fixes: d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed") Cc: stable <stable@vger.kernel.org> Signed-off-by: Filip Schauer <filip@mg6.at> Link: https://lore.kernel.org/r/20210727112311.GA7645@DESKTOP-E8BN1B0.localdomain Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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0d9f837c |
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17-Jun-2021 |
Jason Gunthorpe <jgg@ziepe.ca> |
driver core: Export device_driver_attach() This is intended as a replacement API for device_bind_driver(). It has at least the following benefits: - Internal locking. Few of the users of device_bind_driver() follow the locking rules - Calls device driver probe() internally. Notably this means that devm support for probe works correctly as probe() error will call devres_release_all() - struct device_driver -> dev_groups is supported - Simplified calling convention, no need to manually call probe(). The general usage is for situations that already know what driver to bind and need to ensure the bind is synchronized with other logic. Call device_driver_attach() after device_add(). If probe() returns a failure then this will be preserved up through to the error return of device_driver_attach(). Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20210617142218.1877096-6-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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45ddcb42 |
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17-Jun-2021 |
Christoph Hellwig <hch@lst.de> |
driver core: Don't return EPROBE_DEFER to userspace during sysfs bind EPROBE_DEFER is an internal kernel error code and it should not be leaked to userspace via the bind_store() sysfs. Userspace doesn't have this constant and cannot understand it. Further, it doesn't really make sense to have userspace trigger a deferred probe via bind_store(), which could eventually succeed, while simultaneously returning an error back. Resolve this by splitting driver_probe_device so that the version used by the sysfs binding that turns EPROBE_DEFER into -EAGAIN, while the one used for internally binding keeps the error code, and calls driver_deferred_probe_add where needed. This also allows to nicely split out the defer_all_probes / probe_count checks so that they actually allow for full device_{block,unblock}_probing protection while not bothering the sysfs bind case. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20210617142218.1877096-5-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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ef6dcbdd |
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17-Jun-2021 |
Christoph Hellwig <hch@lst.de> |
driver core: Flow the return code from ->probe() through to sysfs bind Currently really_probe() returns 1 on success and 0 if the probe() call fails. This return code arrangement is designed to be useful for __device_attach_driver() which is walking the device list and trying every driver. 0 means to keep trying. However, it is not useful for the other places that call through to really_probe() that do actually want to see the probe() return code. For instance bind_store() would be better to return the actual error code from the driver's probe method, not discarding it and returning -ENODEV. Reorganize things so that really_probe() returns the error code from ->probe as a (inverted) positive number, and 0 for successful attach. With this, __device_attach_driver can ignore the (positive) probe errors, return 1 to exit the loop for a successful binding and pass on the other negative errors, while device_driver_attach simplify inverts the positive errors and returns all errors to the sysfs code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/20210617142218.1877096-4-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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e1499647 |
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17-Jun-2021 |
Christoph Hellwig <hch@lst.de> |
driver core: Better distinguish probe errors in really_probe really_probe tries to special case errors from ->probe, but due to all other initialization added to the function over time now a lot of internal errors hit that code path as well. Untangle that by adding a new probe_err local variable and apply the special casing only to that. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Link: https://lore.kernel.org/r/20210617142218.1877096-3-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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204db60c |
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17-Jun-2021 |
Jason Gunthorpe <jgg@ziepe.ca> |
driver core: Pull required checks into driver_probe_device() Checking if the dev is dead or if the dev is already bound is a required precondition to invoking driver_probe_device(). All the call chains leading here duplicate these checks. Add it directly to driver_probe_device() so the precondition is clear and remove the checks from device_driver_attach() and __driver_attach_async_helper(). The other call chain going through __device_attach_driver() does have these same checks but they are inlined into logic higher up the call stack and can't be removed. The sysfs uAPI call chain starting at bind_store() is a bit confused because it reads dev->driver unlocked and returns -ENODEV if it is !NULL, otherwise it reads it again under lock and returns 0 if it is !NULL. Fix this to always return -EBUSY and always read dev->driver under its lock. Done in preparation for the next patches which will add additional callers to driver_probe_device() and will need these checks as well. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> [hch: drop the extra checks in device_driver_attach and bind_store] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/20210617142218.1877096-2-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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72a91f19 |
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23-Mar-2021 |
Ahmad Fatoum <a.fatoum@pengutronix.de> |
driver core: add helper for deferred probe reason setting We now have three places within the same file doing the same operation of freeing this pointer and setting it anew. A helper makes this arguably easier to read, so add one. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Link: https://lore.kernel.org/r/20210323153714.25120-2-a.fatoum@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d46f3e3e |
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01-Apr-2021 |
Saravana Kannan <saravanak@google.com> |
driver core: Improve fw_devlink & deferred_probe_timeout interaction deferred_probe_timeout kernel commandline parameter allows probing of consumer devices if the supplier devices don't have any drivers. fw_devlink=on will indefintely block probe() calls on a device if all its suppliers haven't probed successfully. This completely skips calls to driver_deferred_probe_check_state() since that's only called when a .probe() function calls framework APIs. So fw_devlink=on breaks deferred_probe_timeout. deferred_probe_timeout in its current state also ignores a lot of information that's now available to the kernel. It assumes all suppliers that haven't probed when the timer expires (or when initcalls are done on a static kernel) will never probe and fails any calls to acquire resources from these unprobed suppliers. However, this assumption by deferred_probe_timeout isn't true under many conditions. For example: - If the consumer happens to be before the supplier in the deferred probe list. - If the supplier itself is waiting on its supplier to probe. This patch fixes both these issues by relaxing device links between devices only if the supplier doesn't have any driver that could match with (NOT bound to) the supplier device. This way, we only fail attempts to acquire resources from suppliers that truly don't have any driver vs suppliers that just happen to not have probed yet. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210402040342.2944858-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d225ef6f |
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23-Mar-2021 |
Jia-Ju Bai <baijiaju1990@gmail.com> |
base: dd: fix error return code of driver_sysfs_add() When device_create_file() fails and returns a non-zero value, no error return code of driver_sysfs_add() is assigned. To fix this bug, ret is assigned with the return value of device_create_file(), and then ret is checked. Reported-by: TOTE Robot <oslab@tsinghua.edu.cn> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Link: https://lore.kernel.org/r/20210324023405.12465-1-baijiaju1990@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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e611f8cd |
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24-Mar-2021 |
Yogesh Lal <ylal@codeaurora.org> |
driver core: Use unbound workqueue for deferred probes Deferred probe usually runs only on pinned kworkers, which might take longer time if a device contains multiple sub-devices. One such case is of sound card on mobile devices, where we have good number of mixers and controls per mixer. We observed boot up improvement - deferred probes take ~600ms when bound to little core kworker and ~200ms when deferred probe is queued on unbound wq. This is due to scheduler moving the worker running deferred probe work to big CPUs. Without this change, we see the worker is running on LITTLE CPU due to affinity. Since kworker runs deferred probe of several devices, the locality may not be important. Also, init thread executing driver initcalls, can potentially migrate as it has cpu affinity set to all cpus.In addition to this, async probes use unbounded workqueue. So, using unbounded wq for deferred probes looks to be similar to these w.r.t. scheduling behavior. Signed-off-by: Yogesh Lal <ylal@codeaurora.org> Link: https://lore.kernel.org/r/1616583698-6398-1-git-send-email-ylal@codeaurora.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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b6f617df |
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02-Mar-2021 |
Saravana Kannan <saravanak@google.com> |
driver core: Update device link status properly for device_bind_driver() Device link status was not getting updated correctly when device_bind_driver() is called on a device. This causes a warning[1]. Fix this by updating device links that can be updated and dropping device links that can't be updated to a sensible state. [1] - https://lore.kernel.org/lkml/56f7d032-ba5a-a8c7-23de-2969d98c527e@nvidia.com/ Tested-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210302211133.2244281-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f2db85b6 |
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02-Mar-2021 |
Saravana Kannan <saravanak@google.com> |
driver core: Avoid pointless deferred probe attempts There's no point in adding a device to the deferred probe list if we know for sure that it doesn't have a matching driver. So, check if a device can match with a driver before adding it to the deferred probe list. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210302211133.2244281-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2942df67 |
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16-Feb-2021 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
driver core: dd: remove deferred_devices variable No need to save the debugfs dentry for the "devices_deferred" debugfs file (gotta love the juxtaposition), if we need to remove it we can look it up from debugfs itself. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: linux-kernel@vger.kernel.org Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/20210216142400.3759099-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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eed6e418 |
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01-Apr-2021 |
Saravana Kannan <saravanak@google.com> |
driver core: Fix locking bug in deferred_probe_timeout_work_func() list_for_each_entry_safe() is only useful if we are deleting nodes in a linked list within the loop. It doesn't protect against other threads adding/deleting nodes to the list in parallel. We need to grab deferred_probe_mutex when traversing the deferred_probe_pending_list. Cc: stable@vger.kernel.org Fixes: 25b4e70dcce9 ("driver core: allow stopping deferred probe after init") Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210402040342.2944858-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f0acf637 |
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18-Mar-2021 |
Ahmad Fatoum <a.fatoum@pengutronix.de> |
driver core: clear deferred probe reason on probe retry When retrying a deferred probe, any old defer reason string should be discarded. Otherwise, if the probe is deferred again at a different spot, but without setting a message, the now incorrect probe reason will remain. This was observed with the i.MX I2C driver, which ultimately failed to probe due to lack of the GPIO driver. The probe defer for GPIO doesn't record a message, but a previous probe defer to clock_get did. This had the effect that /sys/kernel/debug/devices_deferred listed a misleading probe deferral reason. Cc: stable <stable@vger.kernel.org> Fixes: d090b70ede02 ("driver core: add deferring probe reason to devices_deferred property") Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Link: https://lore.kernel.org/r/20210319110459.19966-1-a.fatoum@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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895bee27 |
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12-Jan-2021 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
Revert "driver core: Reorder devices on successful probe" This reverts commit 5b6164d3465fcc13b5679c860c452963443172a7. Stephan reports problems with this commit, so revert it for now. Fixes: 5b6164d3465f ("driver core: Reorder devices on successful probe") Link: https://lore.kernel.org/r/X/ycQpu7NIGI969v@gerhold.net Reported-by: Stephan Gerhold <stephan@gerhold.net> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Rafael. J. Wysocki <rafael@kernel.org> Cc: Thierry Reding <treding@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d0243bbd |
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05-Jan-2021 |
Meng Li <Meng.Li@windriver.com> |
drivers core: Free dma_range_map when driver probe failed There will be memory leak if driver probe failed. Trace as below: backtrace: [<000000002415258f>] kmemleak_alloc+0x3c/0x50 [<00000000f447ebe4>] __kmalloc+0x208/0x530 [<0000000048bc7b3a>] of_dma_get_range+0xe4/0x1b0 [<0000000041e39065>] of_dma_configure_id+0x58/0x27c [<000000006356866a>] platform_dma_configure+0x2c/0x40 ...... [<000000000afcf9b5>] ret_from_fork+0x10/0x3c This issue is introduced by commit e0d072782c73("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset "). It doesn't free dma_range_map when driver probe failed and cause above memory leak. So, add code to free it in error path. Fixes: e0d072782c73 ("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset ") Cc: stable@vger.kernel.org Signed-off-by: Meng Li <Meng.Li@windriver.com> Link: https://lore.kernel.org/r/20210105070927.14968-1-Meng.Li@windriver.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2c3dc643 |
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22-Nov-2020 |
Julian Wiedmann <jwi@linux.ibm.com> |
driver core: make driver_probe_device() static It's only used inside drivers/base/dd.c Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Link: https://lore.kernel.org/r/20201123111938.18968-1-jwi@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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5b6164d3 |
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03-Dec-2020 |
Thierry Reding <treding@nvidia.com> |
driver core: Reorder devices on successful probe Device drivers usually depend on the fact that the devices that they control are suspended in the same order that they were probed in. In most cases this is already guaranteed via deferred probe. However, there's one case where this can still break: if a device is instantiated before a dependency (for example if it appears before the dependency in device tree) but gets probed only after the dependency is probed. Instantiation order would cause the dependency to get probed later, in which case probe of the original device would be deferred and the suspend/resume queue would get reordered properly. However, if the dependency is provided by a built-in driver and the device depending on that driver is controlled by a loadable module, which may only get loaded after the root filesystem has become available, we can be faced with a situation where the probe order ends up being different from the suspend/resume order. One example where this happens is on Tegra186, where the ACONNECT is listed very early in device tree (sorted by unit-address) and depends on BPMP (listed very late because it has no unit-address) for power domains and clocks/resets. If the ACONNECT driver is built-in, there is no problem because it will be probed before BPMP, causing a probe deferral and that in turn reorders the suspend/resume queue. However, if built as a module, it will end up being probed after BPMP, and therefore not result in a probe deferral, and therefore the suspend/resume queue will stay in the instantiation order. This in turn causes problems because ACONNECT will be resumed before BPMP, which will result in a hang because the ACONNECT's power domain cannot be powered on as long as the BPMP is still suspended. Fix this by always reordering devices on successful probe. This ensures that the suspend/resume queue is always in probe order and hence meets the natural expectations of drivers vs. their dependencies. Reported-by: Jonathan Hunter <jonathanh@nvidia.com> Acked-by: Rafael. J. Wysocki <rafael@kernel.org> Signed-off-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/20201203175756.1405564-1-thierry.reding@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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c84b9090 |
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20-Nov-2020 |
Saravana Kannan <saravanak@google.com> |
Revert "driver core: fw_devlink: Add support for batching fwnode parsing" This reverts commit 716a7a25969003d82ab738179c3f1068a120ed11. The fw_devlink_pause/resume() APIs added by the commit being reverted were a first cut attempt at optimizing boot time. But these APIs don't fully solve the problem and are very fragile (can only be used for the top level devices being added). This series replaces them with a much better optimization that works for all device additions and also has the benefit of reducing the complexity of the firmware (DT, EFI) specific code and abstracting out common code to driver core. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20201121020232.908850-7-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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999032ec |
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20-Nov-2020 |
Saravana Kannan <saravanak@google.com> |
Revert "driver core: Remove check in driver_deferred_probe_force_trigger()" This reverts commit fefcfc968723caf93318613a08e1f3ad07a6154f. The reverted commit is fixing commit 716a7a259690 ("driver core: fw_devlink: Add support for batching fwnode parsing"). Since the original commit will be reverted, the fix can be reverted too. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20201121020232.908850-5-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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96d8a916 |
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20-Nov-2020 |
Saravana Kannan <saravanak@google.com> |
Revert "driver core: Don't do deferred probe in parallel with kernel_init thread" This reverts commit cec72f3efc6272420c2c2c699607f03d09b93e41. Commit cec72f3efc62 ("driver core: Don't do deferred probe in parallel with kernel_init thread") was fixing a commit 716a7a259690 ("driver core: fw_devlink: Add support for batching fwnode parsing"). Since the commit being fixed itself is going to be reverted, the fix can also be reverted. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20201121020232.908850-4-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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9226c504 |
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22-Oct-2020 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
PM: runtime: Resume the device earlier in __device_release_driver() Since the device is resumed from runtime-suspend in __device_release_driver() anyway, it is better to do that before looking for busy managed device links from it to consumers, because if there are any, device_links_unbind_consumers() will be called and it will cause the consumer devices' drivers to unbind, so the consumer devices will be runtime-resumed. In turn, resuming each consumer device will cause the supplier to be resumed and when the runtime PM references from the given consumer to it are dropped, it may be suspended. Then, the runtime-resume of the next consumer will cause the supplier to resume again and so on. Update the code accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support") Cc: All applicable <stable@vger.kernel.org> # All applicable Tested-by: Xiang Chen <chenxiang66@hisilicon.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d6e36668 |
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21-Oct-2020 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
PM: runtime: Drop pm_runtime_clean_up_links() After commit d12544fb2aa9 ("PM: runtime: Remove link state checks in rpm_get/put_supplier()") nothing prevents the consumer device's runtime PM from acquiring additional references to the supplier device after pm_runtime_clean_up_links() has run (or even while it is running), so calling this function from __device_release_driver() may be pointless (or even harmful). Moreover, it ignores stateless device links, so the runtime PM handling of managed and stateless device links is inconsistent because of it, so better get rid of it entirely. Fixes: d12544fb2aa9 ("PM: runtime: Remove link state checks in rpm_get/put_supplier()") Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: 5.1+ <stable@vger.kernel.org> # 5.1+ Tested-by: Xiang Chen <chenxiang66@hisilicon.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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0a0f0d8b |
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22-Sep-2020 |
Christoph Hellwig <hch@lst.de> |
dma-mapping: split <linux/dma-mapping.h> Split out all the bits that are purely for dma_map_ops implementations and related code into a new <linux/dma-map-ops.h> header so that they don't get pulled into all the drivers. That also means the architecture specific <asm/dma-mapping.h> is not pulled in by <linux/dma-mapping.h> any more, which leads to a missing includes that were pulled in by the x86 or arm versions in a few not overly portable drivers. Signed-off-by: Christoph Hellwig <hch@lst.de>
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948b3edb |
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16-Sep-2020 |
Joe Perches <joe@perches.com> |
drivers core: Miscellaneous changes for sysfs_emit Change additional instances that could use sysfs_emit and sysfs_emit_at that the coccinelle script could not convert. o macros creating show functions with ## concatenation o unbound sprintf uses with buf+len for start of output to sysfs_emit_at o returns with ?: tests and sprintf to sysfs_emit o sysfs output with struct class * not struct device * arguments Miscellanea: o remove unnecessary initializations around these changes o consistently use int len for return length of show functions o use octal permissions and not S_<FOO> o rename a few show function names so DEVICE_ATTR_<FOO> can be used o use DEVICE_ATTR_ADMIN_RO where appropriate o consistently use const char *output for strings o checkpatch/style neatening Signed-off-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/8bc24444fe2049a9b2de6127389b57edfdfe324d.1600285923.git.joe@perches.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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aa838896 |
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16-Sep-2020 |
Joe Perches <joe@perches.com> |
drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions Convert the various sprintf fmaily calls in sysfs device show functions to sysfs_emit and sysfs_emit_at for PAGE_SIZE buffer safety. Done with: $ spatch -sp-file sysfs_emit_dev.cocci --in-place --max-width=80 . And cocci script: $ cat sysfs_emit_dev.cocci @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - sprintf(buf, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - snprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - scnprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; expression chr; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - strcpy(buf, chr); + sysfs_emit(buf, chr); ...> } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - sprintf(buf, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - snprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - scnprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... - len += scnprintf(buf + len, PAGE_SIZE - len, + len += sysfs_emit_at(buf, len, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; expression chr; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { ... - strcpy(buf, chr); - return strlen(buf); + return sysfs_emit(buf, chr); } Signed-off-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/3d033c33056d88bbe34d4ddb62afd05ee166ab9a.1600285923.git.joe@perches.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
e3aa745f |
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02-Aug-2020 |
Zenghui Yu <yuzenghui@huawei.com> |
driver core: Use the ktime_us_delta() helper Use the ktime_us_delta() helper to measure the driver probe time. Given the helpers already returns an s64 value, let's drop the unnecessary casting to s64 as well. There is no functional change. Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> Link: https://lore.kernel.org/r/20200803033343.1178-1-yuzenghui@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d090b70e |
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13-Jul-2020 |
Andrzej Hajda <a.hajda@samsung.com> |
driver core: add deferring probe reason to devices_deferred property /sys/kernel/debug/devices_deferred property contains list of deferred devices. This list does not contain reason why the driver deferred probe, the patch improves it. The natural place to set the reason is dev_err_probe function introduced recently, ie. if dev_err_probe will be called with -EPROBE_DEFER instead of printk the message will be attached to a deferred device and printed when user reads devices_deferred property. Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> Reviewed-by: Mark Brown <broonie@kernel.org> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20200713144324.23654-3-a.hajda@samsung.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
65488832 |
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08-Jul-2020 |
Lukas Wunner <lukas@wunner.de> |
driver core: Avoid binding drivers to dead devices Commit 3451a495ef24 ("driver core: Establish order of operations for device_add and device_del via bitflag") sought to prevent asynchronous driver binding to a device which is being removed. It added a per-device "dead" flag which is checked in the following code paths: * asynchronous binding in __driver_attach_async_helper() * synchronous binding in device_driver_attach() * asynchronous binding in __device_attach_async_helper() It did *not* check the flag upon: * synchronous binding in __device_attach() However __device_attach() may also be called asynchronously from: deferred_probe_work_func() bus_probe_device() device_initial_probe() __device_attach() So if the commit's intention was to check the "dead" flag in all asynchronous code paths, then a check is also necessary in __device_attach(). Add the missing check. Fixes: 3451a495ef24 ("driver core: Establish order of operations for device_add and device_del via bitflag") Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v5.1+ Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Link: https://lore.kernel.org/r/de88a23a6fe0ef70f7cfd13c8aea9ab51b4edab6.1594214103.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
b292b50b |
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12-Jul-2020 |
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> |
driver core: Fix probe_count imbalance in really_probe() syzbot is reporting hung task in wait_for_device_probe() [1]. At least, we always need to decrement probe_count if we incremented probe_count in really_probe(). However, since I can't find "Resources present before probing" message in the console log, both "this message simply flowed off" and "syzbot is not hitting this path" will be possible. Therefore, while we are at it, let's also prepare for concurrent wait_for_device_probe() calls by replacing wake_up() with wake_up_all(). [1] https://syzkaller.appspot.com/bug?id=25c833f1983c9c1d512f4ff860dd0d7f5a2e2c0f Reported-by: syzbot <syzbot+805f5f6ae37411f15b64@syzkaller.appspotmail.com> Fixes: 7c35e699c88bd607 ("driver core: Print device when resources present in really_probe()") Cc: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/20200713021254.3444-1-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
8fd456ec |
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21-May-2020 |
Saravana Kannan <saravanak@google.com> |
driver core: Add state_synced sysfs file for devices that support it This can be used to check if a device supports sync_state() callbacks and therefore keeps resources left on by the bootloader enabled till all its consumers have probed. This can also be used to check if sync_state() has been called for a device or whether it is still trying to keep resources enabled because they were left enabled by the bootloader and all its consumers haven't probed yet. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20200521191800.136035-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
cec72f3e |
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01-Jul-2020 |
Saravana Kannan <saravanak@google.com> |
driver core: Don't do deferred probe in parallel with kernel_init thread The current deferred probe implementation can mess up suspend/resume ordering if deferred probe thread is kicked off in parallel with the main initcall thread (kernel_init thread) [1]. For example: Say device-B is a consumer of device-A. Initcall thread Deferred probe thread =============== ===================== 1. device-A is added. 2. device-B is added. 3. dpm_list is now [device-A, device-B]. 4. driver-A defers probe of device-A. 5. device-A is moved to end of dpm_list 6. dpm_list is now [device-B, device-A] 7. driver-B is registereed and probes device-B. 8. dpm_list stays as [device-B, device-A]. The reverse order of dpm_list is used for suspend. So in this case device-A would incorrectly get suspended before device-B. Commit 716a7a259690 ("driver core: fw_devlink: Add support for batching fwnode parsing") kicked off the deferred probe thread early during boot to run in parallel with the initcall thread and caused suspend/resume regressions. This patch removes the parallel run of the deferred probe thread to avoid the suspend/resume regressions. [1] - https://lore.kernel.org/lkml/CAGETcx8W96KAw-d_siTX4qHB_-7ddk0miYRDQeHE6E0_8qx-6Q@mail.gmail.com/ Fixes: 716a7a259690 ("driver core: fw_devlink: Add support for batching fwnode parsing") Signed-off-by: Saravana Kannan <saravanak@google.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20200701194259.3337652-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
fe940d73 |
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08-Jul-2020 |
Lukas Wunner <lukas@wunner.de> |
driver core: Drop mention of obsolete bus rwsem from kernel-doc 15 years ago, commit 6eded061b126 ("Fix up bus code and remove use of rwsem") removed the bus rwsem, but left over a reference to it in a kernel-doc comment. Drop it. Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/b1af31b0e351bcbc056fe1ec44500737a7998d43.1594210157.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
fefcfc96 |
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17-May-2020 |
Saravana Kannan <saravanak@google.com> |
driver core: Remove check in driver_deferred_probe_force_trigger() The whole point behind adding driver_deferred_probe_force_trigger() in commit 716a7a259690 ("driver core: fw_devlink: Add support for batching fwnode parsing") was to skip the check for driver_deferred_probe_enable. Otherwise, it's identical to driver_deferred_probe_trigger(). Delete the check in driver_deferred_probe_force_trigger() so that fw_devlink_pause() and fw_devlink_resume() can kick off deferred probe as intended. Without doing this forced deferred probe trigger, some platforms seem to be crashing during boot because they assume probe order of devices. Fixes: 716a7a259690 ("driver core: fw_devlink: Add support for batching fwnode parsing") Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20200517173453.157703-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
716a7a25 |
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14-May-2020 |
Saravana Kannan <saravanak@google.com> |
driver core: fw_devlink: Add support for batching fwnode parsing The amount of time spent parsing fwnodes of devices can become really high if the devices are added in an non-ideal order. Worst case can be O(N^2) when N devices are added. But this can be optimized to O(N) by adding all the devices and then parsing all their fwnodes in one batch. This commit adds fw_devlink_pause() and fw_devlink_resume() to allow doing this. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20200515053500.215929-4-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
eb7fbc9f |
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11-Apr-2020 |
Christophe JAILLET <christophe.jaillet@wanadoo.fr> |
driver core: Add missing '\n' in log messages Message logged by 'dev_xxx()' or 'pr_xxx()' should end with a '\n'. While at it, convert some "printk(KERN_" into equivalent but less verbose (pr|dev)_xxx functions. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Link: https://lore.kernel.org/r/20200411133158.27390-1-christophe.jaillet@wanadoo.fr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
35a67236 |
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22-Apr-2020 |
John Stultz <john.stultz@linaro.org> |
driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires In commit c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic"), we set the default driver_deferred_probe_timeout value to 30 seconds to allow for drivers that are missing dependencies to have some time so that the dependency may be loaded from userland after initcalls_done is set. However, Yoshihiro Shimoda reported that on his device that expects to have unmet dependencies (due to "optional links" in its devicetree), was failing to mount the NFS root. In digging further, it seemed the problem was that while the device properly probes after waiting 30 seconds for any missing modules to load, the ip_auto_config() had already failed, resulting in NFS to fail. This was due to ip_auto_config() calling wait_for_device_probe() which doesn't wait for the driver_deferred_probe_timeout to fire. This patch tries to fix the issue by creating a waitqueue for the driver_deferred_probe_timeout, and calling wait_event() to make sure driver_deferred_probe_timeout is zero in wait_for_device_probe() to make sure all the probing is finished. The downside to this solution is that kernel functionality that uses wait_for_device_probe(), will block until the driver_deferred_probe_timeout fires, regardless of if there is any missing dependencies. However, the previous patch reverts the default timeout value to zero, so this side-effect will only affect users who specify a driver_deferred_probe_timeout= value as a boot argument, where the additional delay would be beneficial to allow modules to load later during boot. Thanks to Geert for chasing down that ip_auto_config was why NFS was failing in this case! Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Rob Herring <robh@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Basil Eljuse <Basil.Eljuse@arm.com> Cc: Ferry Toth <fntoth@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: linux-pm@vger.kernel.org Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Fixes: c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") Signed-off-by: John Stultz <john.stultz@linaro.org> Link: https://lore.kernel.org/r/20200422203245.83244-4-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
4ccc03e2 |
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22-Apr-2020 |
John Stultz <john.stultz@linaro.org> |
driver core: Use dev_warn() instead of dev_WARN() for deferred_probe_timeout warnings In commit c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") and following changes the logic was changes slightly so that if there is no driver to match whats found in the dtb, we wait the sepcified seconds for modules to be loaded by userland, and then timeout, where as previously we'd print "ignoring dependency for device, assuming no driver" and immediately return -ENODEV after initcall_done. However, in the timeout case (which previously existed but was practicaly un-used without a boot argument), the timeout message uses dev_WARN(). This means folks are now seeing a big backtrace in their boot logs if there a entry in their dts that doesn't have a driver. To fix this, lets use dev_warn(), instead of dev_WARN() to match the previous error path. Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Rob Herring <robh@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Basil Eljuse <Basil.Eljuse@arm.com> Cc: Ferry Toth <fntoth@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: linux-pm@vger.kernel.org Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Fixes: c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") Signed-off-by: John Stultz <john.stultz@linaro.org> Link: https://lore.kernel.org/r/20200422203245.83244-3-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
ce68929f |
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22-Apr-2020 |
John Stultz <john.stultz@linaro.org> |
driver core: Revert default driver_deferred_probe_timeout value to 0 This patch addresses a regression in 5.7-rc1+ In commit c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic"), we both cleaned up the logic and also set the default driver_deferred_probe_timeout value to 30 seconds to allow for drivers that are missing dependencies to have some time so that the dependency may be loaded from userland after initcalls_done is set. However, Yoshihiro Shimoda reported that on his device that expects to have unmet dependencies (due to "optional links" in its devicetree), was failing to mount the NFS root. In digging further, it seemed the problem was that while the device properly probes after waiting 30 seconds for any missing modules to load, the ip_auto_config() had already failed, resulting in NFS to fail. This was due to ip_auto_config() calling wait_for_device_probe() which doesn't wait for the driver_deferred_probe_timeout to fire. Fixing that issue is possible, but could also introduce 30 second delays in bootups for users who don't have any missing dependencies, which is not ideal. So I think the best solution to avoid any regressions is to revert back to a default timeout value of zero, and allow systems that need to utilize the timeout in order for userland to load any modules that supply misisng dependencies in the dts to specify the timeout length via the exiting documented boot argument. Thanks to Geert for chasing down that ip_auto_config was why NFS was failing in this case! Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Rob Herring <robh@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Basil Eljuse <Basil.Eljuse@arm.com> Cc: Ferry Toth <fntoth@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Anders Roxell <anders.roxell@linaro.org> Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Fixes: c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") Signed-off-by: John Stultz <john.stultz@linaro.org> Link: https://lore.kernel.org/r/20200422203245.83244-2-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a3a87d66 |
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24-Mar-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
driver core: Replace open-coded list_last_entry() There is a place in the code where open-coded version of list entry accessors list_last_entry() is used. Replace that with the standard macro. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200324122023.9649-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
927f8287 |
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24-Mar-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
driver core: Read atomic counter once in driver_probe_done() Between printing the debug message and actual check atomic counter can be altered. For better debugging experience read atomic counter value only once. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Ferry Toth <fntoth@gmail.com> Link: https://lore.kernel.org/r/20200324122023.9649-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
64c775fb |
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24-Feb-2020 |
John Stultz <john.stultz@linaro.org> |
driver core: Rename deferred_probe_timeout and make it global Since other subsystems (like regulator) have similar arbitrary timeouts for how long they try to resolve driver dependencies, rename deferred_probe_timeout to driver_deferred_probe_timeout and set it as global, so it can be shared. Cc: linux-pm@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Thierry Reding <treding@nvidia.com> Cc: Mark Brown <broonie@kernel.org> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Todd Kjos <tkjos@google.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Kevin Hilman <khilman@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Rob Herring <robh@kernel.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Link: https://lore.kernel.org/r/20200225050828.56458-6-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
0e9f8d09 |
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24-Feb-2020 |
John Stultz <john.stultz@linaro.org> |
driver core: Remove driver_deferred_probe_check_state_continue() Now that driver_deferred_probe_check_state() works better, and we've converted the only user of driver_deferred_probe_check_state_continue() we can simply remove it and simplify some of the logic. Cc: linux-pm@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Thierry Reding <treding@nvidia.com> Cc: Mark Brown <broonie@kernel.org> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Todd Kjos <tkjos@google.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Kevin Hilman <khilman@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Rob Herring <robh@kernel.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Link: https://lore.kernel.org/r/20200225050828.56458-5-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
e2cec7d6 |
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24-Feb-2020 |
John Stultz <john.stultz@linaro.org> |
driver core: Set deferred_probe_timeout to a longer default if CONFIG_MODULES is set When using modules, its common for the modules not to be loaded until quite late by userland. With the current code, driver_deferred_probe_check_state() will stop returning EPROBE_DEFER after late_initcall, which can cause module dependency resolution to fail after that. So allow a longer window of 30 seconds (picked somewhat arbitrarily, but influenced by the similar regulator core timeout value) in the case where modules are enabled. Cc: linux-pm@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Thierry Reding <treding@nvidia.com> Cc: Mark Brown <broonie@kernel.org> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Todd Kjos <tkjos@google.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Kevin Hilman <khilman@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Rob Herring <robh@kernel.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Link: https://lore.kernel.org/r/20200225050828.56458-3-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c8c43cee |
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24-Feb-2020 |
John Stultz <john.stultz@linaro.org> |
driver core: Fix driver_deferred_probe_check_state() logic driver_deferred_probe_check_state() has some uninituitive behavior. * From boot to late_initcall, it returns -EPROBE_DEFER * From late_initcall to the deferred_probe_timeout (if set) it returns -ENODEV * If the deferred_probe_timeout it set, after it fires, it returns -ETIMEDOUT This is a bit confusing, as its useful to have the function return -EPROBE_DEFER while the timeout is still running. This behavior has resulted in the somwhat duplicative driver_deferred_probe_check_state_continue() function being added. Thus this patch tries to improve the logic, so that it behaves as such: * If late_initcall has passed, and modules are not enabled it returns -ENODEV * If modules are enabled and deferred_probe_timeout is set, it returns -EPROBE_DEFER until the timeout, afterwhich it returns -ETIMEDOUT. * In all other cases, it returns -EPROBE_DEFER This will make the deferred_probe_timeout value much more functional, and will allow us to consolidate the driver_deferred_probe_check_state() and driver_deferred_probe_check_state_continue() logic in a later patch. Cc: linux-pm@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Thierry Reding <treding@nvidia.com> Cc: Mark Brown <broonie@kernel.org> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Todd Kjos <tkjos@google.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Kevin Hilman <khilman@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Rob Herring <robh@kernel.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Link: https://lore.kernel.org/r/20200225050828.56458-2-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
7c35e699 |
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06-Dec-2019 |
Geert Uytterhoeven <geert+renesas@glider.be> |
driver core: Print device when resources present in really_probe() If a device already has devres items attached before probing, a warning backtrace is printed. However, this backtrace does not reveal the offending device, leaving the user uninformed. Furthermore, using WARN_ON() causes systems with panic-on-warn to reboot. Fix this by replacing the WARN_ON() by a dev_crit() message. Abort probing the device, to prevent doing more damage to the device's resources. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20191206132219.28908-1-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
33cbfe54 |
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27-Aug-2019 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
Revert "driver core: Add edit_links() callback for drivers" This reverts commit 134b23eec9e3a3c795a6ceb0efe2fa63e87983b2. Based on a lot of email and in-person discussions, this patch series is being reworked to address a number of issues that were pointed out that needed to be taken care of before it should be merged. It will be resubmitted with those changes hopefully soon. Cc: Frank Rowand <frowand.list@gmail.com> Cc: Saravana Kannan <saravanak@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
23b69044 |
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31-Jul-2019 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
driver core: add dev_groups to all drivers Add the ability for the driver core to create and remove a list of attribute groups automatically when the device is bound/unbound from a specific driver. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Tested-by: Richard Gong <richard.gong@linux.intel.com> Link: https://lore.kernel.org/r/20190731124349.4474-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
134b23ee |
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31-Jul-2019 |
Saravana Kannan <saravanak@google.com> |
driver core: Add edit_links() callback for drivers The driver core/bus adding supplier-consumer dependencies by default enables functional dependencies to be tracked correctly even when the consumer devices haven't had their drivers registered or loaded (if they are modules). However, when the bus incorrectly adds dependencies that it shouldn't have added, the devices might never probe. For example, if device-C is a consumer of device-S and they have phandles to each other in DT, the following could happen: 1. Device-S get added first. 2. The bus add_links() callback will (incorrectly) try to link it as a consumer of device-C. 3. Since device-C isn't present, device-S will be put in "waiting-for-supplier" list. 4. Device-C gets added next. 5. All devices in "waiting-for-supplier" list are retried for linking. 6. Device-S gets linked as consumer to Device-C. 7. The bus add_links() callback will (correctly) try to link it as a consumer of device-S. 8. This isn't allowed because it would create a cyclic device links. Neither devices will get probed since the supplier is marked as dependent on the consumer. And the consumer will never probe because the consumer can't get resources from the supplier. Without this patch, things stay in this broken state. However, with this patch, the execution will continue like this: 9. Device-C's driver is loaded. 10. Device-C's driver removes Device-S as a consumer of Device-C. 11. Device-C's driver adds Device-C as a consumer of Device-S. 12. Device-S probes. 14. Device-C probes. kbuild test robot reported missing documentation for device.has_edit_links Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20190731221721.187713-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
62a6bc3a |
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21-Jun-2019 |
Thierry Reding <treding@nvidia.com> |
driver: core: Allow subsystems to continue deferring probe Some subsystems, such as pinctrl, allow continuing to defer probe indefinitely. This is useful for devices that depend on resources provided by devices that are only probed after the init stage. One example of this can be seen on Tegra, where the DPAUX hardware contains pinmuxing controls for pins that it shares with an I2C controller. The I2C controller is typically used for communication with a monitor over HDMI (DDC). However, other instances of the I2C controller are used to access system critical components, such as a PMIC. The I2C controller driver will therefore usually be a builtin driver, whereas the DPAUX driver is part of the display driver that is loaded from a module to avoid bloating the kernel image with all of the DRM/KMS subsystem. In this particular case the pins used by this I2C/DDC controller become accessible very late in the boot process. However, since the controller is only used in conjunction with display, that's not an issue. Unfortunately the driver core currently outputs a warning message when a device fails to get the pinctrl before the end of the init stage. That can be confusing for the user because it may sound like an unwanted error occurred, whereas it's really an expected and harmless situation. In order to eliminate this warning, this patch allows callers of the driver_deferred_probe_check_state() helper to specify that they want to continue deferring probe, regardless of whether we're past the init stage or not. All of the callers of that function are updated for the new signature, but only the pinctrl subsystem passes a true value in the new persist parameter if appropriate. Signed-off-by: Thierry Reding <treding@nvidia.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/20190621151725.20414-1-thierry.reding@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
0b777eee |
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28-Mar-2019 |
John Garry <john.garry@huawei.com> |
driver core: Postpone DMA tear-down until after devres release for probe failure In commit 376991db4b64 ("driver core: Postpone DMA tear-down until after devres release"), we changed the ordering of tearing down the device DMA ops and releasing all the device's resources; this was because the DMA ops should be maintained until we release the device's managed DMA memories. However, we have seen another crash on an arm64 system when a device driver probe fails: hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2 scsi host1: hisi_sas_v3_hw BUG: Bad page state in process swapper/0 pfn:313f5 page:ffff7e0000c4fd40 count:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe00000001000(reserved) raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set bad because of flags: 0x1000(reserved) Modules linked in: CPU: 49 PID: 1 Comm: swapper/0 Not tainted 5.1.0-rc1-43081-g22d97fd-dirty #1433 Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI RC0 - V1.12.01 01/29/2019 Call trace: dump_backtrace+0x0/0x118 show_stack+0x14/0x1c dump_stack+0xa4/0xc8 bad_page+0xe4/0x13c free_pages_check_bad+0x4c/0xc0 __free_pages_ok+0x30c/0x340 __free_pages+0x30/0x44 __dma_direct_free_pages+0x30/0x38 dma_direct_free+0x24/0x38 dma_free_attrs+0x9c/0xd8 dmam_release+0x20/0x28 release_nodes+0x17c/0x220 devres_release_all+0x34/0x54 really_probe+0xc4/0x2c8 driver_probe_device+0x58/0xfc device_driver_attach+0x68/0x70 __driver_attach+0x94/0xdc bus_for_each_dev+0x5c/0xb4 driver_attach+0x20/0x28 bus_add_driver+0x14c/0x200 driver_register+0x6c/0x124 __pci_register_driver+0x48/0x50 sas_v3_pci_driver_init+0x20/0x28 do_one_initcall+0x40/0x25c kernel_init_freeable+0x2b8/0x3c0 kernel_init+0x10/0x100 ret_from_fork+0x10/0x18 Disabling lock debugging due to kernel taint BUG: Bad page state in process swapper/0 pfn:313f6 page:ffff7e0000c4fd80 count:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 89.322983] flags: 0xfffe00000001000(reserved) raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 The crash occurs for the same reason. In this case, on the really_probe() failure path, we are still clearing the DMA ops prior to releasing the device's managed memories. This patch fixes this issue by reordering the DMA ops teardown and the call to devres_release_all() on the failure path. Reported-by: Xiang Chen <chenxiang66@hisilicon.com> Tested-by: Xiang Chen <chenxiang66@hisilicon.com> Signed-off-by: John Garry <john.garry@huawei.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
1ea61b68 |
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13-Feb-2019 |
Feng Tang <feng.tang@intel.com> |
async: Add cmdline option to specify drivers to be async probed Asynchronous driver probing can help much on kernel fastboot, and this option can provide a flexible way to optimize and quickly verify async driver probe. Also it will help in below cases: * Some driver actually covers several families of HWs, some of which could use async probing while others don't. So we can't simply turn on the PROBE_PREFER_ASYNCHRONOUS flag in driver, but use this cmdline option, like igb driver async patch discussed at https://www.spinics.net/lists/netdev/msg545986.html * For SOC (System on Chip) with multiple spi or i2c controllers, most of the slave spi/i2c devices will be assigned with fixed controller number, while async probing may make those controllers get different index for each boot, which prevents those controller drivers to be async probed. For platforms not using these spi/i2c slave devices, they can use this cmdline option to benefit from the async probing. Suggested-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
376991db |
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07-Feb-2019 |
Geert Uytterhoeven <geert+renesas@glider.be> |
driver core: Postpone DMA tear-down until after devres release When unbinding the (IOMMU-enabled) R-Car SATA device on Salvator-XS (R-Car H3 ES2.0), in preparation of rebinding against vfio-platform for device pass-through for virtualization: echo ee300000.sata > /sys/bus/platform/drivers/sata_rcar/unbind the kernel crashes with: Unable to handle kernel paging request at virtual address ffffffbf029ffffc Mem abort info: ESR = 0x96000006 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 swapper pgtable: 4k pages, 39-bit VAs, pgdp = 000000007e8c586c [ffffffbf029ffffc] pgd=000000073bfc6003, pud=000000073bfc6003, pmd=0000000000000000 Internal error: Oops: 96000006 [#1] SMP Modules linked in: CPU: 0 PID: 1098 Comm: bash Not tainted 5.0.0-rc5-salvator-x-00452-g37596f884f4318ef #287 Hardware name: Renesas Salvator-X 2nd version board based on r8a7795 ES2.0+ (DT) pstate: 60400005 (nZCv daif +PAN -UAO) pc : __free_pages+0x8/0x58 lr : __dma_direct_free_pages+0x50/0x5c sp : ffffff801268baa0 x29: ffffff801268baa0 x28: 0000000000000000 x27: ffffffc6f9c60bf0 x26: ffffffc6f9c60bf0 x25: ffffffc6f9c60810 x24: 0000000000000000 x23: 00000000fffff000 x22: ffffff8012145000 x21: 0000000000000800 x20: ffffffbf029fffc8 x19: 0000000000000000 x18: ffffffc6f86c42c8 x17: 0000000000000000 x16: 0000000000000070 x15: 0000000000000003 x14: 0000000000000000 x13: ffffff801103d7f8 x12: 0000000000000028 x11: ffffff8011117604 x10: 0000000000009ad8 x9 : ffffff80110126d0 x8 : ffffffc6f7563000 x7 : 6b6b6b6b6b6b6b6b x6 : 0000000000000018 x5 : ffffff8011cf3cc8 x4 : 0000000000004000 x3 : 0000000000080000 x2 : 0000000000000001 x1 : 0000000000000000 x0 : ffffffbf029fffc8 Process bash (pid: 1098, stack limit = 0x00000000c38e3e32) Call trace: __free_pages+0x8/0x58 __dma_direct_free_pages+0x50/0x5c arch_dma_free+0x1c/0x98 dma_direct_free+0x14/0x24 dma_free_attrs+0x9c/0xdc dmam_release+0x18/0x20 release_nodes+0x25c/0x28c devres_release_all+0x48/0x4c device_release_driver_internal+0x184/0x1f0 device_release_driver+0x14/0x1c unbind_store+0x70/0xb8 drv_attr_store+0x24/0x34 sysfs_kf_write+0x4c/0x64 kernfs_fop_write+0x154/0x1c4 __vfs_write+0x34/0x164 vfs_write+0xb4/0x16c ksys_write+0x5c/0xbc __arm64_sys_write+0x14/0x1c el0_svc_common+0x98/0x114 el0_svc_handler+0x1c/0x24 el0_svc+0x8/0xc Code: d51b4234 17fffffa a9bf7bfd 910003fd (b9403404) ---[ end trace 8c564cdd3a1a840f ]--- While I've bisected this to commit e8e683ae9a736407 ("iommu/of: Fix probe-deferral"), and reverting that commit on post-v5.0-rc4 kernels does fix the problem, this turned out to be a red herring. On arm64, arch_teardown_dma_ops() resets dev->dma_ops to NULL. Hence if a driver has used a managed DMA allocation API, the allocated DMA memory will be freed using the direct DMA ops, while it may have been allocated using a custom DMA ops (iommu_dma_ops in this case). Fix this by reversing the order of the calls to devres_release_all() and arch_teardown_dma_ops(). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: stable <stable@vger.kernel.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
e7dd4010 |
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31-Jan-2019 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
driver core: Add device link flag DL_FLAG_AUTOPROBE_CONSUMER Add a new device link flag, DL_FLAG_AUTOPROBE_CONSUMER, to request the driver core to probe for a consumer driver automatically after binding a driver to the supplier device on a persistent managed device link. As unbinding the supplier driver on a managed device link causes the consumer driver to be detached from its device automatically, this flag provides a complementary mechanism which is needed to address some "composite device" use cases. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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c37e20ea |
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22-Jan-2019 |
Alexander Duyck <alexander.h.duyck@linux.intel.com> |
driver core: Attach devices on CPU local to device node Call the asynchronous probe routines on a CPU local to the device node. By doing this we should be able to improve our initialization time significantly as we can avoid having to access the device from a remote node which may introduce higher latency. For example, in the case of initializing memory for NVDIMM this can have a significant impact as initialing 3TB on remote node can take up to 39 seconds while initialing it on a local node only takes 23 seconds. It is situations like this where we will see the biggest improvement. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ef0ff683 |
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22-Jan-2019 |
Alexander Duyck <alexander.h.duyck@linux.intel.com> |
driver core: Probe devices asynchronously instead of the driver Probe devices asynchronously instead of the driver. This results in us seeing the same behavior if the device is registered before the driver or after. This way we can avoid serializing the initialization should the driver not be loaded until after the devices have already been added. The motivation behind this is that if we have a set of devices that take a significant amount of time to load we can greatly reduce the time to load by processing them in parallel instead of one at a time. In addition, each device can exist on a different node so placing a single thread on one CPU to initialize all of the devices for a given driver can result in poor performance on a system with multiple nodes. This approach can reduce the time needed to scan SCSI LUNs significantly. The only way to realize that speedup is by enabling more concurrency which is what is achieved with this patch. To achieve this it was necessary to add a new member "async_driver" to the device_private structure to store the driver pointer while we wait on the deferred probe call. Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ed88747c |
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22-Jan-2019 |
Alexander Duyck <alexander.h.duyck@linux.intel.com> |
device core: Consolidate locking and unlocking of parent and device Try to consolidate all of the locking and unlocking of both the parent and device when attaching or removing a driver from a given device. To do that I first consolidated the lock pattern into two functions __device_driver_lock and __device_driver_unlock. After doing that I then created functions specific to attaching and detaching the driver while acquiring these locks. By doing this I was able to reduce the number of spots where we touch need_parent_lock from 12 down to 4. This patch should produce no functional changes, it is meant to be a code clean-up/consolidation only. Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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3451a495 |
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22-Jan-2019 |
Alexander Duyck <alexander.h.duyck@linux.intel.com> |
driver core: Establish order of operations for device_add and device_del via bitflag Add an additional bit flag to the device_private struct named "dead". This additional flag provides a guarantee that when a device_del is executed on a given interface an async worker will not attempt to attach the driver following the earlier device_del call. Previously this guarantee was not present and could result in the device_del call attempting to remove a driver from an interface only to have the async worker attempt to probe the driver later when it finally completes the asynchronous probe call. One additional change added was that I pulled the check for dev->driver out of the __device_attach_driver call and instead placed it in the __device_attach_async_helper call. This was motivated by the fact that the only other caller of this, __device_attach, had already taken the device_lock() and checked for dev->driver. Instead of testing for this twice in this path it makes more sense to just consolidate the dev->dead and dev->driver checks together into one set of checks. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
e121a833 |
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13-Dec-2018 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
driver core: Add missing dev->bus->need_parent_lock checks __device_release_driver() has to check dev->bus->need_parent_lock before dropping the parent lock and acquiring it again as it may attempt to drop a lock that hasn't been acquired or lock a device that shouldn't be locked and create a lock imbalance. Fixes: 8c97a46af04b (driver core: hold dev's parent lock when needed) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: stable <stable@vger.kernel.org> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c37d721c |
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28-Nov-2018 |
Alexander Duyck <alexander.h.duyck@linux.intel.com> |
driver core: Move async_synchronize_full call Move the async_synchronize_full call out of __device_release_driver and into driver_detach. The idea behind this is that the async_synchronize_full call will only guarantee that any existing async operations are flushed. This doesn't do anything to guarantee that a hotplug event that may occur while we are doing the release of the driver will not be asynchronously scheduled. By moving this into the driver_detach path we can avoid potential deadlocks as we aren't holding the device lock at this point and we should not have the driver we want to flush loaded so the flush will take care of any asynchronous events the driver we are detaching might have scheduled. Fixes: 765230b5f084 ("driver-core: add asynchronous probing support for drivers") Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
dbf03d65 |
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06-Nov-2018 |
Randy Dunlap <rdunlap@infradead.org> |
driver core: fix comments for device_block_probing() Correct function name and spelling/typo for device_block_probing() in drivers/base/dd.c. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
63c98047 |
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28-Oct-2018 |
Muchun Song <smuchun@gmail.com> |
driver core: Replace simple_strtol by kstrtoint The simple_strtol() function is deprecated, use kstrtoint() instead. Signed-off-by: Muchun Song <smuchun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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dc3c0550 |
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24-Aug-2018 |
Christoph Hellwig <hch@lst.de> |
dma-mapping: remove dma_deconfigure This goes through a lot of hooks just to call arch_teardown_dma_ops. Replace it with a direct call instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
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#
ccf640f4 |
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24-Aug-2018 |
Christoph Hellwig <hch@lst.de> |
dma-mapping: remove dma_configure There is no good reason for this indirection given that the method always exists. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
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#
722e5f2b |
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10-Jul-2018 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
driver core: Partially revert "driver core: correct device's shutdown order" Commit 52cdbdd49853 (driver core: correct device's shutdown order) introduced a regression by breaking device shutdown on some systems. Namely, the devices_kset_move_last() call in really_probe() added by that commit is a mistake as it may cause parents to follow children in the devices_kset list which then causes shutdown to fail. For example, if a device has children before really_probe() is called for it (which is not uncommon), that call will cause it to be reordered after the children in the devices_kset list and the ordering of that list will not reflect the correct device shutdown order any more. Also it causes the devices_kset list to be constantly reordered until all drivers have been probed which is totally pointless overhead in the majority of cases and it only covered an issue with system shutdown, while system-wide suspend/resume potentially had the same issue on the affected platforms (which was not covered). Moreover, the shutdown issue originally addressed by the change in really_probe() made by commit 52cdbdd49853 is not present in 4.18-rc any more, since dra7 started to use the sdhci-omap driver which doesn't disable any regulators during shutdown, so the really_probe() part of commit 52cdbdd49853 can be safely reverted. [The original issue was related to the omap_hsmmc driver used by dra7 previously.] For the above reasons, revert the really_probe() modifications made by commit 52cdbdd49853. The other code changes made by commit 52cdbdd49853 are useful and they need not be reverted. Fixes: 52cdbdd49853 (driver core: correct device's shutdown order) Link: https://lore.kernel.org/lkml/CAFgQCTt7VfqM=UyCnvNFxrSw8Z6cUtAi3HUwR4_xPAc03SgHjQ@mail.gmail.com/ Reported-by: Pingfan Liu <kernelfans@gmail.com> Tested-by: Pingfan Liu <kernelfans@gmail.com> Reviewed-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
25b4e70d |
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09-Jul-2018 |
Rob Herring <robh@kernel.org> |
driver core: allow stopping deferred probe after init Deferred probe will currently wait forever on dependent devices to probe, but sometimes a driver will never exist. It's also not always critical for a driver to exist. Platforms can rely on default configuration from the bootloader or reset defaults for things such as pinctrl and power domains. This is often the case with initial platform support until various drivers get enabled. There's at least 2 scenarios where deferred probe can render a platform broken. Both involve using a DT which has more devices and dependencies than the kernel supports. The 1st case is a driver may be disabled in the kernel config. The 2nd case is the kernel version may simply not have the dependent driver. This can happen if using a newer DT (provided by firmware perhaps) with a stable kernel version. Deferred probe issues can be difficult to debug especially if the console has dependencies or userspace fails to boot to a shell. There are also cases like IOMMUs where only built-in drivers are supported, so deferring probe after initcalls is not needed. The IOMMU subsystem implemented its own mechanism to handle this using OF_DECLARE linker sections. This commit adds makes ending deferred probe conditional on initcalls being completed or a debug timeout. Subsystems or drivers may opt-in by calling driver_deferred_probe_check_init_done() instead of unconditionally returning -EPROBE_DEFER. They may use additional information from DT or kernel's config to decide whether to continue to defer probe or not. The timeout mechanism is intended for debug purposes and WARNs loudly. The remaining deferred probe pending list will also be dumped after the timeout. Not that this timeout won't work for the console which needs to be enabled before userspace starts. However, if the console's dependencies are resolved, then the kernel log will be printed (as opposed to no output). Cc: Alexander Graf <agraf@suse.de> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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28af109a |
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08-Jul-2018 |
Javier Martinez Canillas <javierm@redhat.com> |
driver core: add a debugfs entry to show deferred devices With Device Trees (DT), the dependencies of the devices are defined in the DT, then the drivers parse that information to lookup the needed resources that have as dependencies. Since drivers and devices are registered in a non-deterministic way, it is possible that a device that is a dependency has not been registered yet by the time that is looked up. In this case the driver that requires this dependency cannot probe and has to defer it. So the driver core adds it to a list of deferred devices that is iterated again every time that a new driver is probed successfully. For debugging purposes it may be useful to know what are the devices whose probe function was deferred. Add a debugfs entry showing that information. $ cat /sys/kernel/debug/devices_deferred 48070000.i2c:twl@48:bci musb-hdrc.0.auto omapdrm.0 This information could be obtained partially by enabling debugging, but it means that the kernel log has to be parsed and the probe deferral balanced with the successes. This can be error probe and has to be done in a ad-hoc manner by everyone who needs to debug these kind of issues. Since the information is already known by the kernel, just show it to make it easier to debug. Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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0a50f61c |
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20-Jun-2018 |
Todd Poynor <toddpoynor@google.com> |
drivers: base: initcall_debug logs for driver probe times Add initcall_debug logs for each driver device probe call, for example: probe of a3800000.ramoops returned 1 after 3007 usecs This replaces the previous code added to report times for deferred probes. It also reports OF platform bus device creates that were formerly lumped together in a single entry for function of_platform_default_populate_init, as well as helping to annotate other initcalls that involve device probing. Remove restriction on printing probe times only during initcalls, since initcall_debug now continues to show driver timing info past the boot phase. Signed-off-by: Todd Poynor <toddpoynor@google.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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b06c0b2f |
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12-Jun-2018 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
Revert "PM / runtime: Fixup reference counting of device link suppliers at probe" Revert commit 1e8378619841 (PM / runtime: Fixup reference counting of device link suppliers at probe), as it has introduced a regression and the condition it was designed to address should be covered by the existing code. Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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8c97a46a |
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30-May-2018 |
Martin Liu <liumartin@google.com> |
driver core: hold dev's parent lock when needed SoC have internal I/O buses that can't be proved for devices. The devices on the buses can be accessed directly without additinal configuration required. This type of bus is represented as "simple-bus". In some platforms, we name "soc" with "simple-bus" attribute and many devices are hooked under it described in DT (device tree). In commit bf74ad5bc417 ("Hold the device's parent's lock during probe and remove") to solve USB subsystem lock sequence since USB device's characteristic. Thus "soc" needs to be locked whenever a device and driver's probing happen under "soc" bus. During this period, an async driver tries to probe a device which is under the "soc" bus would be blocked until previous driver finish the probing and release "soc" lock. And the next probing under the "soc" bus need to wait for async finish. Because of that, driver's async probe for init time improvement will be shadowed. Since many devices don't have USB devices' characteristic, they actually don't need parent's lock. Thus, we introduce a lock flag in bus_type struct and driver core would lock the parent lock base on the flag. For USB, we set this flag in usb_bus_type to keep original lock behavior in driver core. Async probe could have more benefit after this patch. Signed-off-by: Martin Liu <liumartin@google.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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1e837861 |
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18-May-2018 |
Ulf Hansson <ulf.hansson@linaro.org> |
PM / runtime: Fixup reference counting of device link suppliers at probe In the driver core, before it invokes really_probe() it runtime resumes the suppliers for the device via calling pm_runtime_get_suppliers(), which also increases the runtime PM usage count for each of the available supplier. This makes sense, as to be able to allow the consumer device to be probed by its driver. However, if the driver decides to add a new supplier link during ->probe(), hence updating the list of suppliers, the following call to pm_runtime_put_suppliers(), invoked after really_probe() in the driver core, we get into trouble. More precisely, pm_runtime_put() gets called also for the new supplier(s), which is wrong as the driver core, didn't trigger pm_runtime_get_sync() to be called for it in the first place. In other words, the new supplier may be runtime suspended even in cases when it shouldn't. Fix this behaviour, by runtime resume suppliers according to the same conditions as managed by the runtime PM core, when runtime resume callbacks are being invoked. Additionally, don't try to runtime suspend any of the suppliers after really_probe(), but instead rely on that to happen via the consumer device, when it becomes runtime suspended. Fixes: 21d5c57b3726 (PM / runtime: Use device links) Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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494fd7b7 |
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10-Apr-2018 |
Feng Kan <fkan@apm.com> |
PM / core: fix deferred probe breaking suspend resume order When bridge and its endpoint is enumerated the devices are added to the dpm list. Afterward, the bridge defers probe when IOMMU is not ready. This causes the bridge to be moved to the end of the dpm list when deferred probe kicks in. The order of the dpm list for bridge and endpoint is reversed. Add reordering code to move the bridge and its children and consumers to the end of the pm list so the order for suspend and resume is not altered. The code also move device and its children and consumers to the tail of device_kset list if it is registered. Signed-off-by: Toan Le <toanle@apm.com> Signed-off-by: Feng Kan <fkan@apm.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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1fe56e0c |
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15-Mar-2018 |
Arend van Spriel <aspriel@gmail.com> |
drivers: base: remove check for callback in coredump_store() The check for the .coredump() callback in coredump_store() is redundant. It is already assured the device driver implements the callback upon creating the coredump sysfs entry. Signed-off-by: Arend van Spriel <aspriel@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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3c47d19f |
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11-Jan-2018 |
Arend van Spriel <aspriel@gmail.com> |
drivers: base: add coredump driver ops This adds the coredump driver operation. When the driver defines it a coredump file is added in the sysfs folder of the device upon driver binding. The file is removed when the driver is unbound. User-space can trigger a coredump for this device by echo'ing to the coredump file. Signed-off-by: Arend van Spriel <aspriel@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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32825709 |
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07-Nov-2017 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
driver core: Remove redundant license text Now that the SPDX tag is in all driver core 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: Johannes Berg <johannes@sipsolutions.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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989d42e8 |
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07-Nov-2017 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
driver core: add SPDX identifiers to all driver core files It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the driver core 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: Johannes Berg <johannes@sipsolutions.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: William Breathitt Gray <vilhelm.gray@gmail.com> 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>
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0ff26c66 |
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02-Nov-2017 |
Adrian Hunter <adrian.hunter@intel.com> |
driver core: Fix device link deferred probe A device probe deferred because of a device link is never probed again because it is not added to the deferred_probe_pending_list. Add it, taking care of the race with driver_deferred_probe_trigger(). Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
08810a41 |
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25-Oct-2017 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
PM / core: Add NEVER_SKIP and SMART_PREPARE driver flags The motivation for this change is to provide a way to work around a problem with the direct-complete mechanism used for avoiding system suspend/resume handling for devices in runtime suspend. The problem is that some middle layer code (the PCI bus type and the ACPI PM domain in particular) returns positive values from its system suspend ->prepare callbacks regardless of whether the driver's ->prepare returns a positive value or 0, which effectively prevents drivers from being able to control the direct-complete feature. Some drivers need that control, however, and the PCI bus type has grown its own flag to deal with this issue, but since it is not limited to PCI, it is better to address it by adding driver flags at the core level. To that end, add a driver_flags field to struct dev_pm_info for flags that can be set by device drivers at the probe time to inform the PM core and/or bus types, PM domains and so on on the capabilities and/or preferences of device drivers. Also add two static inline helpers for setting that field and testing it against a given set of flags and make the driver core clear it automatically on driver remove and probe failures. Define and document two PM driver flags related to the direct- complete feature: NEVER_SKIP and SMART_PREPARE that can be used, respectively, to indicate to the PM core that the direct-complete mechanism should never be used for the device and to inform the middle layer code (bus types, PM domains etc) that it can only request the PM core to use the direct-complete mechanism for the device (by returning a positive value from its ->prepare callback) if it also has been requested by the driver. While at it, make the core check pm_runtime_suspended() when setting power.direct_complete so that it doesn't need to be checked by ->prepare callbacks. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
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#
1f5000bd |
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25-Jul-2017 |
Todd Poynor <toddpoynor@google.com> |
initcall_debug: add deferred probe times initcall_debug attributes all deferred device probe retries for the late_initcall level to function deferred_probe_initcall. Add logs of the individual device probe routines called, to identify which drivers are executing for how long during the initcall path. Deferred probes that occur after initcall processing are not shown. Example log messages added: [ 0.505119] deferred probe my-sound-device @ 6 [ 0.517656] deferred probe my-sound-device returned after 1227 usecs Signed-off-by: Todd Poynor <toddpoynor@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
1455cf8d |
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19-Jul-2017 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
driver core: emit uevents when device is bound to a driver There are certain touch controllers that may come up in either normal (application) or boot mode, depending on whether firmware/configuration is corrupted when they are powered on. In boot mode the kernel does not create input device instance (because it does not necessarily know the characteristics of the input device in question). Another number of controllers does not store firmware in a non-volatile memory, and they similarly need to have firmware loaded before input device instance is created. There are also other types of devices with similar behavior. There is a desire to be able to trigger firmware loading via udev, but it has to happen only when driver is bound to a physical device (i2c or spi). These udev actions can not use ADD events, as those happen too early, so we are introducing BIND and UNBIND events that are emitted at the right moment. Also, many drivers create additional driver-specific device attributes when binding to the device, to provide userspace with additional controls. The new events allow userspace to adjust these driver-specific attributes without worrying that they are not there yet. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
09515ef5 |
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10-Apr-2017 |
Sricharan R <sricharan@codeaurora.org> |
of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices Configuring DMA ops at probe time will allow deferring device probe when the IOMMU isn't available yet. The dma_configure for the device is now called from the generic device_attach callback just before the bus/driver probe is called. This way, configuring the DMA ops for the device would be called at the same place for all bus_types, hence the deferred probing mechanism should work for all buses as well. pci_bus_add_devices (platform/amba)(_device_create/driver_register) | | pci_bus_add_device (device_add/driver_register) | | device_attach device_initial_probe | | __device_attach_driver __device_attach_driver | driver_probe_device | really_probe | dma_configure Similarly on the device/driver_unregister path __device_release_driver is called which inturn calls dma_deconfigure. This patch changes the dma ops configuration to probe time for both OF and ACPI based platform/amba/pci bus devices. Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci part) Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sricharan R <sricharan@codeaurora.org> Signed-off-by: Joerg Roedel <jroedel@suse.de>
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c7334ce8 |
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14-Jan-2017 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
Revert "driver core: Add deferred_probe attribute to devices in sysfs" This reverts commit 6751667a29d6fd64afb9ce30567ad616b68ed789. Rob Herring objected to it, and a replacement for it will be added using debugfs in the future. Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Reported-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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6751667a |
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16-Aug-2016 |
Ben Hutchings <ben.hutchings@codethink.co.uk> |
driver core: Add deferred_probe attribute to devices in sysfs It is sometimes useful to know that a device is on the deferred probe list rather than, say, not having a driver available. Expose this information to user-space. Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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21d5c57b |
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30-Oct-2016 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
PM / runtime: Use device links Modify the runtime PM framework to use device links to ensure that supplier devices will not be suspended if any of their consumer devices are active. The idea is to reference count suppliers on the consumer's resume and drop references to them on its suspend. The information on whether or not the supplier has been reference counted by the consumer's (runtime) resume is stored in a new field (rpm_active) in the link object for each link. It may be necessary to clean up those references when the supplier is unbinding and that's why the links whose status is DEVICE_LINK_SUPPLIER_UNBIND are skipped by the runtime suspend and resume code. The above means that if the consumer device is probed in the runtime-active state, the supplier has to be resumed and reference counted by device_link_add() so the code works as expected on its (runtime) suspend. There is a new flag, DEVICE_LINK_RPM_ACTIVE, to tell device_link_add() about that (in which case the caller is responsible for making sure that the consumer really will be runtime-active when runtime PM is enabled for it). The other new link flag, DEVICE_LINK_PM_RUNTIME, tells the core whether or not the link should be used for runtime PM at all. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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9ed98953 |
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30-Oct-2016 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
driver core: Functional dependencies tracking support Currently, there is a problem with taking functional dependencies between devices into account. What I mean by a "functional dependency" is when the driver of device B needs device A to be functional and (generally) its driver to be present in order to work properly. This has certain consequences for power management (suspend/resume and runtime PM ordering) and shutdown ordering of these devices. In general, it also implies that the driver of A needs to be working for B to be probed successfully and it cannot be unbound from the device before the B's driver. Support for representing those functional dependencies between devices is added here to allow the driver core to track them and act on them in certain cases where applicable. The argument for doing that in the driver core is that there are quite a few distinct use cases involving device dependencies, they are relatively hard to get right in a driver (if one wants to address all of them properly) and it only gets worse if multiplied by the number of drivers potentially needing to do it. Morever, at least one case (asynchronous system suspend/resume) cannot be handled in a single driver at all, because it requires the driver of A to wait for B to suspend (during system suspend) and the driver of B to wait for A to resume (during system resume). For this reason, represent dependencies between devices as "links", with the help of struct device_link objects each containing pointers to the "linked" devices, a list node for each of them, status information, flags, and an RCU head for synchronization. Also add two new list heads, representing the lists of links to the devices that depend on the given one (consumers) and to the devices depended on by it (suppliers), and a "driver presence status" field (needed for figuring out initial states of device links) to struct device. The entire data structure consisting of all of the lists of link objects for all devices is protected by a mutex (for link object addition/removal and for list walks during device driver probing and removal) and by SRCU (for list walking in other case that will be introduced by subsequent change sets). If CONFIG_SRCU is not selected, however, an rwsem is used for protecting the entire data structure. In addition, each link object has an internal status field whose value reflects whether or not drivers are bound to the devices pointed to by the link or probing/removal of their drivers is in progress etc. That field is only modified under the device links mutex, but it may be read outside of it in some cases (introduced by subsequent change sets), so modifications of it are annotated with WRITE_ONCE(). New links are added by calling device_link_add() which takes three arguments: pointers to the devices in question and flags. In particular, if DL_FLAG_STATELESS is set in the flags, the link status is not to be taken into account for this link and the driver core will not manage it. In turn, if DL_FLAG_AUTOREMOVE is set in the flags, the driver core will remove the link automatically when the consumer device driver unbinds from it. One of the actions carried out by device_link_add() is to reorder the lists used for device shutdown and system suspend/resume to put the consumer device along with all of its children and all of its consumers (and so on, recursively) to the ends of those lists in order to ensure the right ordering between all of the supplier and consumer devices. For this reason, it is not possible to create a link between two devices if the would-be supplier device already depends on the would-be consumer device as either a direct descendant of it or a consumer of one of its direct descendants or one of its consumers and so on. There are two types of link objects, persistent and non-persistent. The persistent ones stay around until one of the target devices is deleted, while the non-persistent ones are removed automatically when the consumer driver unbinds from its device (ie. they are assumed to be valid only as long as the consumer device has a driver bound to it). Persistent links are created by default and non-persistent links are created when the DL_FLAG_AUTOREMOVE flag is passed to device_link_add(). Both persistent and non-persistent device links can be deleted with an explicit call to device_link_del(). Links created without the DL_FLAG_STATELESS flag set are managed by the driver core using a simple state machine. There are 5 states each link can be in: DORMANT (unused), AVAILABLE (the supplier driver is present and functional), CONSUMER_PROBE (the consumer driver is probing), ACTIVE (both supplier and consumer drivers are present and functional), and SUPPLIER_UNBIND (the supplier driver is unbinding). The driver core updates the link state automatically depending on what happens to the linked devices and for each link state specific actions are taken in addition to that. For example, if the supplier driver unbinds from its device, the driver core will also unbind the drivers of all of its consumers automatically under the assumption that they cannot function properly without the supplier. Analogously, the driver core will only allow the consumer driver to bind to its device if the supplier driver is present and functional (ie. the link is in the AVAILABLE state). If that's not the case, it will rely on the existing deferred probing mechanism to wait for the supplier driver to become available. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
bdacd1b4 |
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11-Oct-2016 |
Rob Herring <robh@kernel.org> |
driver core: fix smatch warning on dev->bus check Commit d42a09802174 (driver core: skip removal test for non-removable drivers) introduced a smatch warning: drivers/base/dd.c:386 really_probe() warn: variable dereferenced before check 'dev->bus' (see line 373) Fix the warning by removing the dev->bus NULL check. dev->bus will never be NULL, so the check was unnecessary. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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c5f06274 |
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11-Oct-2016 |
Rob Herring <robh@kernel.org> |
driver core: skip removal test for non-removable drivers Some drivers do not support removal/unbinding. These drivers should have drv->suppress_bind_attrs set to true, so use that to skip the removal test. This doesn't fix anything reported so far, but should prevent some other cases. Some drivers will need fixes to set suppress_bind_attrs to avoid this test. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=177021 Fixes: bea5b158ff0d ("driver core: add test of driver remove calls during probe") Reported-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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4bdb3550 |
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10-Oct-2016 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
driver core: Add a wrapper around __device_release_driver() Add an internal wrapper around __device_release_driver() that will acquire device locks and do the necessary checks before calling it. The next patch will make use of it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2c507e46 |
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30-Aug-2016 |
Bhaktipriya Shridhar <bhaktipriya96@gmail.com> |
device core: Remove deprecated create_singlethread_workqueue The workqueue "deferred_wq" queues a single work item &deferred_probe_work and hence doesn't require ordering. It is involved in probing devices and is not being used on a memory reclaim path. Hence, it has been converted to use system_wq. System workqueues have been able to handle high level of concurrency for a long time now and hence it's not required to have a singlethreaded workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue created with create_singlethread_workqueue(), system_wq allows multiple work items to overlap executions even on the same CPU; however, a per-cpu workqueue doesn't have any CPU locality or global ordering guarantee unless the target CPU is explicitly specified and thus the increase of local concurrency shouldn't make any difference. The work item has been flushed in driver_probe_done() to ensure that there are no pending tasks while disconnecting the driver. Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
bea5b158 |
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11-Aug-2016 |
Rob Herring <robh@kernel.org> |
driver core: add test of driver remove calls during probe In recent discussions on ksummit-discuss[1], it was suggested to do a sequence of probe, remove, probe for testing driver remove paths. This adds a kconfig option for said test. [1] https://lists.linuxfoundation.org/pipermail/ksummit-discuss/2016-August/003459.html Suggested-by: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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c6e360a0 |
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03-May-2016 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
Revert "base: dd: don't remove driver_data in -EPROBE_DEFER case" This reverts commit ded9db380d34344ee5263002570b9b8b705f7830. Thierry Reding writes: This causes a boot regression on at least one board, caused by one of the drivers looking at driver data to check whether or not the driver has properly loaded. If the code encounters a non-NULL pointer it tries to dereference it, but because it's already been freed there is no memory backing it and things crash. I don't think keeping stale pointers around is a good idea. The whole point of setting this to NULL in the core is so that probe failures result in the same starting conditions no matter what. Can we please get this reverted? Reported-by: Thierry Reding <thierry.reding@gmail.com> Cc: Yi Zhang <yizhang_hust@163.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ded9db38 |
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08-Mar-2016 |
Yi Zhang <yizhang_hust@163.com> |
base: dd: don't remove driver_data in -EPROBE_DEFER case the driver_data may be used for sanity check, it fails the probe() if driver_data is NULL after it is re-triggered. for example, soc_probe() in sound/soc/soc-core.c Signed-off-by: Yi Zhang <yizhang_hust@163.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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656b8035 |
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15-Feb-2016 |
Tomeu Vizoso <tomeu.vizoso@collabora.com> |
ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match() Allow implementations of the match() callback in struct bus_type to return errors and if it's -EPROBE_DEFER then queue the device for deferred probing. This is useful to buses such as AMBA in which devices are registered before their matching information can be retrieved from the HW (typically because a clock driver hasn't probed yet). [changed if-else code structure, adjusted documentation to match the code, extended comments] Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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3ded9104 |
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11-Jan-2016 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
driver core: Avoid NULL pointer dereferences in device_is_bound() If device_is_bound() is called on a device that's not been registered yet, it will attepmt to dereference dev->p which is NULL, so avoid that by checking dev->p in there against NULL. Fixes: 6b9cb42752da "device core: add device_is_bound()" Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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aa8e54b5 |
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07-Jan-2016 |
Tomeu Vizoso <tomeu.vizoso@collabora.com> |
PM / sleep: Go direct_complete if driver has no callbacks If a suitable prepare callback cannot be found for a given device and its driver has no PM callbacks at all, assume that it can go direct to complete when the system goes to sleep. The reason for this is that there's lots of devices in a system that do no PM at all and there's no reason for them to prevent their ancestors to do direct_complete if they can support it. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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6b9cb427 |
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07-Jan-2016 |
Tomeu Vizoso <tomeu.vizoso@collabora.com> |
device core: add device_is_bound() Adds a function that tells whether a device is already bound to a driver. This is needed to warn when there is an attempt to change the PM domain of a device that has finished probing already. The reason why we want to enforce that is because in the general case that can cause problems and also that we can simplify code quite a bit if we can always assume that. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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14b6257a |
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04-Dec-2015 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
device core: add BUS_NOTIFY_DRIVER_NOT_BOUND notification The users of BUS_NOTIFY_BIND_DRIVER have no chance to do any cleanup in case of a probe failure. In the result there might be problems, such as some resources that had been allocated will continue to be allocated and therefore lead to a resource leak. Introduce a new notification to inform the subscriber that ->probe() failed. Do the same in case of failed device_bind_driver() call. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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5de85b9d |
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18-Nov-2015 |
Ulf Hansson <ulf.hansson@linaro.org> |
PM / runtime: Re-init runtime PM states at probe error and driver unbind There are two common expectations among several subsystems/drivers that deploys runtime PM support, but which isn't met by the driver core. Expectation 1) At ->probe() the subsystem/driver expects the runtime PM status of the device to be RPM_SUSPENDED, which is the initial status being assigned at device registration. This expectation is especially common among some of those subsystems/ drivers that manages devices with an attached PM domain, as those requires the ->runtime_resume() callback at the PM domain level to be invoked during ->probe(). Moreover these subsystems/drivers entirely relies on runtime PM resources being managed at the PM domain level, thus don't implement their own set of runtime PM callbacks. These are two scenarios that suffers from this unmet expectation. i) A failed ->probe() sequence requests probe deferral: ->probe() ... pm_runtime_enable() pm_runtime_get_sync() ... err: pm_runtime_put() pm_runtime_disable() ... As there are no guarantees that such sequence turns the runtime PM status of the device into RPM_SUSPENDED, the re-trying ->probe() may start with the status in RPM_ACTIVE. In such case the runtime PM core won't invoke the ->runtime_resume() callback because of a pm_runtime_get_sync(), as it considers the device to be already runtime resumed. ii) A driver re-bind sequence: At driver unbind, the subsystem/driver's >remove() callback invokes a sequence of runtime PM APIs, to undo actions during ->probe() and to put the device into low power state. ->remove() ... pm_runtime_put() pm_runtime_disable() ... Similar as in the failing ->probe() case, this sequence don't guarantee the runtime PM status of the device to turn into RPM_SUSPENDED. Trying to re-bind the driver thus causes the same issue as when re-trying ->probe(), in the probe deferral scenario. Expectation 2) Drivers that invokes the pm_runtime_irq_safe() API during ->probe(), triggers the runtime PM core to increase the usage count for the device's parent and permanently make it runtime resumed. The usage count is only dropped at device removal, which also allows it to be runtime suspended again. A re-trying ->probe() repeats the call to pm_runtime_irq_safe() and thus once more triggers the usage count of the device's parent to be increased. This leads to not only an imbalance issue of the usage count of the device's parent, but also to keep it runtime resumed permanently even if ->probe() fails. To address these issues, let's change the policy of the driver core to meet these expectations. More precisely, at ->probe() failures and driver unbind, restore the initial states of runtime PM. Although to still allow subsystem's to control PM for devices that doesn't ->probe() successfully, don't restore the initial states unless runtime PM is disabled. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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013c074f |
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10-Nov-2015 |
Strashko, Grygorii <grygorii.strashko@ti.com> |
PM / sleep: prohibit devices probing during suspend/hibernation It is unsafe [1] if probing of devices will happen during suspend or hibernation and system behavior will be unpredictable in this case. So, let's prohibit device's probing in dpm_prepare() and defer their probing instead. The normal behavior will be restored in dpm_complete(). This patch introduces new DD core APIs: device_block_probing() It will disable probing of devices and defer their probes instead. device_unblock_probing() It will restore normal behavior and trigger re-probing of deferred devices. [1] https://lkml.org/lkml/2015/9/11/554 Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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ef0eebc0 |
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20-Oct-2015 |
Douglas Anderson <dianders@chromium.org> |
drivers/pinctrl: Add the concept of an "init" state For pinctrl the "default" state is applied to pins before the driver's probe function is called. This is normally a sensible thing to do, but in some cases can cause problems. That's because the pins will change state before the driver is given a chance to program how those pins should behave. As an example you might have a regulator that is controlled by a PWM (output high = high voltage, output low = low voltage). The firmware might leave this pin as driven high. If we allow the driver core to reconfigure this pin as a PWM pin before the PWM's probe function runs then you might end up running at too low of a voltage while we probe. Let's introudce a new "init" state. If this is defined we'll set pinctrl to this state before probe and then "default" after probe (unless the driver explicitly changed states already). An alternative idea that was thought of was to use the pre-existing "sleep" or "idle" states and add a boolean property that we should start in that mode. This was not done because the "init" state is needed for correctness and those other states are only present (and only transitioned in to and out of) when (optional) power management is enabled. Changes in v3: - Moved declarations to pinctrl/devinfo.h - Fixed author/SoB Changes in v2: - Added comment to pinctrl_init_done() as per Linus W. Signed-off-by: Douglas Anderson <dianders@chromium.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Caesar Wang <wxt@rock-chips.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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52cdbdd4 |
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27-Jul-2015 |
Grygorii Strashko <grygorii.strashko@ti.com> |
driver core: correct device's shutdown order Now device's shutdown sequence is performed in reverse order of their registration in devices_kset list and this sequence corresponds to the reverse device's creation order. So, devices_kset data tracks "parent<-child" device's dependencies only. Unfortunately, that's not enough and causes problems in case of implementing board's specific shutdown procedures. For example [1]: "DRA7XX_evm uses PCF8575 and one of the PCF output lines feeds to MMC/SD and this line should be driven high in order for the MMC/SD to be detected. This line is modelled as regulator and the hsmmc driver takes care of enabling and disabling it. In the case of 'reboot', during shutdown path as part of it's cleanup process the hsmmc driver disables this regulator. This makes MMC boot not functional." To handle this issue the .shutdown() callback could be implemented for PCF8575 device where corresponding GPIO pins will be configured to states, required for correct warm/cold reset. This can be achieved only when all .shutdown() callbacks have been called already for all PCF8575's consumers. But devices_kset is not filled correctly now: devices_kset: Device61 4e000000.dmm devices_kset: Device62 48070000.i2c devices_kset: Device63 48072000.i2c devices_kset: Device64 48060000.i2c devices_kset: Device65 4809c000.mmc ... devices_kset: Device102 fixedregulator-sd ... devices_kset: Device181 0-0020 // PCF8575 devices_kset: Device182 gpiochip496 devices_kset: Device183 0-0021 // PCF8575 devices_kset: Device184 gpiochip480 As can be seen from above .shutdown() callback for PCF8575 will be called before its consumers, which, in turn means, that any changes of PCF8575 GPIO's pins will be or unsafe or overwritten later by GPIO's consumers. The problem can be solved if devices_kset list will be filled not only according device creation order, but also according device's probing order to track "supplier<-consumer" dependencies also. Hence, as a fix, lets add devices_kset_move_last(), devices_kset_move_before(), devices_kset_move_after() and call them from device_move() and also add call of devices_kset_move_last() in really_probe(). After this change all entries in devices_kset will be sorted according to device's creation ("parent<-child") and probing ("supplier<-consumer") order. devices_kset after: devices_kset: Device121 48070000.i2c devices_kset: Device122 i2c-0 ... devices_kset: Device147 regulator.24 devices_kset: Device148 0-0020 devices_kset: Device149 gpiochip496 devices_kset: Device150 0-0021 devices_kset: Device151 gpiochip480 devices_kset: Device152 0-0019 ... devices_kset: Device372 fixedregulator-sd devices_kset: Device373 regulator.29 devices_kset: Device374 4809c000.mmc devices_kset: Device375 mmc0 [1] http://www.spinics.net/lists/linux-mmc/msg29825.html Cc: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
ddef08dd |
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27-Jul-2015 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
Driver core: wakeup the parent device before trying probe If the parent is still suspended when driver probe is attempted, the result may be failure. For example, if the parent is a PCI MFD device that has been suspended when we try to probe our device, any register reads will return 0xffffffff. To fix the problem, making sure the parent is always awake before attempting driver probe. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
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9ba8af66 |
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25-May-2015 |
Shailendra Verma <shailendra.capricorn@gmail.com> |
base:dd - Fix for typo in comment to function driver_deferred_probe_trigger(). Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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80c6e146 |
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21-May-2015 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
driver-core: fix build for !CONFIG_MODULES Commit f2411da74698 ("driver-core: add driver module asynchronous probe support") broke build in case modules are disabled, because in this case "struct module" is not defined and we can't dereference it. Let's define module_requested_async_probing() helper and stub it out if modules are disabled. Reported-by: kbuild test robot <fengguang.wu@intel.com> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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802a87fd |
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20-May-2015 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
driver-core: make __device_attach() static It is only used within dd.c and thus need not be global. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d173a137 |
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30-Mar-2015 |
Luis R. Rodriguez <mcgrof@suse.com> |
driver-core: enable drivers to opt-out of async probe There are drivers that can not be probed asynchronously. One such group is platform drivers registered with platform_driver_probe(), which expects driver's probe routine be discarded after the driver has been registered and initial binding attempt executed. Also platform_driver_probe() an error when no devices were bound to the driver, allowing failing to load such driver module altogether. Other drivers do not work well with asynchronous probing because of driver bug or not optimal driver organization. To allow using such drivers even when user requests asynchronous probing as default boot strategy, let's allow them to opt out. Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f2411da7 |
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30-Mar-2015 |
Luis R. Rodriguez <mcgrof@suse.com> |
driver-core: add driver module asynchronous probe support Some init systems may wish to express the desire to have device drivers run their probe() code asynchronously. This implements support for this and allows userspace to request async probe as a preference through a generic shared device driver module parameter, async_probe. Implementation for async probe is supported through a module parameter given that since synchronous probe has been prevalent for years some userspace might exist which relies on the fact that the device driver will probe synchronously and the assumption that devices it provides will be immediately available after this. Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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765230b5 |
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30-Mar-2015 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
driver-core: add asynchronous probing support for drivers Some devices take a long time when initializing, and not all drivers are suited to initialize their devices when they are open. For example, input drivers need to interrogate their devices in order to publish device's capabilities before userspace will open them. When such drivers are compiled into kernel they may stall entire kernel initialization. This change allows drivers request for their probe functions to be called asynchronously during driver and device registration (manual binding is still synchronous). Because async_schedule is used to perform asynchronous calls module loading will still wait for the probing to complete. Note that the end goal is to make the probing asynchronous by default, so annotating drivers with PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us to speed up boot process while we validating and fixing the rest of the drivers and preparing userspace. This change is based on earlier patch by "Luis R. Rodriguez" <mcgrof@suse.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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13fcffbb |
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10-Mar-2015 |
Mark Brown <broonie@kernel.org> |
driver core: Make probe deferral more quiet Currently probe deferral prints a message every time a device requests deferral at info severity (which is displayed by default). This can have an impact on system boot times with serial consoles and is generally quite noisy. Since subsystems and drivers should already be logging the specific reason for probe deferral in order to aid users in understanding problems the messages from the driver core should be redundant lower the severity of the messages printed, cutting down on the volume of output on the console. This does mean that if the drivers and subsystems aren't doing a good job we get no output on the console by default. Ideally we'd be able to arrange to print if nothing else printed, though that's a little fun. Even better would be to come up with a mechanism that explicitly does dependencies so we don't have to keep polling and erroring. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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bb2b4075 |
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17-Jan-2015 |
Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> |
driver core: use *switch* statement in really_probe() There are series of comparisons of the 'ret' variable on the failure path of really_probe(), so the *switch* statement seems more appropriate there. Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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e90d5532 |
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20-Mar-2015 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
driver core / PM: Add PM domain callbacks for device setup/cleanup If PM domains are in use, it may be necessary to prepare the code handling a PM domain for driver probing. For example, in some cases device drivers rely on the ability to power on the devices with the help of the IO runtime PM framework and the PM domain code needs to be ready for that. Also, if that code has not been fully initialized yet, the driver probing should be deferred. Moreover, after the probing is complete, it may be necessary to put the PM domain in question into the state reflecting the current needs of the devices in it, for example, so that power is not drawn in vain. The same should be done after removing a driver from a device, as the PM domain state may need to be changed to reflect the new situation. For these reasons, introduce new PM domain callbacks, ->activate, ->sync and ->dismiss called, respectively, before probing for a device driver, after the probing has completed successfully and if the probing has failed or the driver has been removed. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Kevin Hilman <khilman@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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41575335 |
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08-Aug-2014 |
Thierry Reding <treding@nvidia.com> |
driver core: Remove kerneldoc from local function The deferred_probe_work_func() function is locally scoped, therefore an associated kerneldoc comment isn't very useful. Replace the kerneldoc opening marker (/**) with a regular block comment marker (/*) to avoid the comment from being parsed by kerneldoc. This gets rid of a warning caused by a missing description for the "work" argument. Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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a996d010 |
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13-Apr-2014 |
Jean Delvare <jdelvare@suse.de> |
driver core: Inline dev_set/get_drvdata dev_set_drvdata and dev_get_drvdata are now simple enough again that we can inline them as they used to be before commit b40284378. Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d4332013 |
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13-Apr-2014 |
Jean Delvare <jdelvare@suse.de> |
driver core: dev_get_drvdata: Don't check for NULL dev There is no point in calling dev_get_drvdata without a valid device. So checking for dev == NULL is pointless. If such a check is ever needed - which I doubt - the driver should do it before calling dev_get_drvdata. We were returning NULL if dev was NULL, which the caller certainly did not expect anyway, so that was only delaying the crash if the caller is not paying attention. Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2c1f1ff0 |
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13-Apr-2014 |
Jean Delvare <jdelvare@suse.de> |
driver core: dev_set_drvdata returns void dev_set_drvdata can no longer fail, so it could return void. All callers have hopefully been updated to no longer check for the return value. Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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1bb6c08a |
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13-Apr-2014 |
Jean Delvare <jdelvare@suse.de> |
driver core: Move driver_data back to struct device Having to allocate memory as part of dev_set_drvdata() is a problem because that memory may never get freed if the device itself is not created. So move driver_data back to struct device. This is a partial revert of commit b4028437. Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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58b116bc |
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28-Apr-2014 |
Grant Likely <grant.likely@linaro.org> |
drivercore: deferral race condition fix When the kernel is built with CONFIG_PREEMPT it is possible to reach a state when all modules loaded but some driver still stuck in the deferred list and there is a need for external event to kick the deferred queue to probe these drivers. The issue has been observed on embedded systems with CONFIG_PREEMPT enabled, audio support built as modules and using nfsroot for root filesystem. The following log fragment shows such sequence when all audio modules were loaded but the sound card is not present since the machine driver has failed to probe due to missing dependency during it's probe. The board is am335x-evmsk (McASP<->tlv320aic3106 codec) with davinci-evm machine driver: ... [ 12.615118] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: ENTER [ 12.719969] davinci_evm sound.3: davinci_evm_probe: ENTER [ 12.725753] davinci_evm sound.3: davinci_evm_probe: snd_soc_register_card [ 12.753846] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: snd_soc_register_component [ 12.922051] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: snd_soc_register_component DONE [ 12.950839] davinci_evm sound.3: ASoC: platform (null) not registered [ 12.957898] davinci_evm sound.3: davinci_evm_probe: snd_soc_register_card DONE (-517) [ 13.099026] davinci-mcasp 4803c000.mcasp: Kicking the deferred list [ 13.177838] davinci-mcasp 4803c000.mcasp: really_probe: probe_count = 2 [ 13.194130] davinci_evm sound.3: snd_soc_register_card failed (-517) [ 13.346755] davinci_mcasp_driver_init: LEAVE [ 13.377446] platform sound.3: Driver davinci_evm requests probe deferral [ 13.592527] platform sound.3: really_probe: probe_count = 0 In the log the machine driver enters it's probe at 12.719969 (this point it has been removed from the deferred lists). McASP driver already executing it's probing (since 12.615118). The machine driver tries to construct the sound card (12.950839) but did not found one of the components so it fails. After this McASP driver registers all the ASoC components (the machine driver still in it's probe function after it failed to construct the card) and the deferred work is prepared at 13.099026 (note that this time the machine driver is not in the lists so it is not going to be handled when the work is executing). Lastly the machine driver exit from it's probe and the core places it to the deferred list but there will be no other driver going to load and the deferred queue is not going to be kicked again - till we have external event like connecting USB stick, etc. The proposed solution is to try the deferred queue once more when the last driver is asking for deferring and we had drivers loaded while this last driver was probing. This way we can avoid drivers stuck in the deferred queue. Signed-off-by: Grant Likely <grant.likely@linaro.org> Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Brown <broonie@kernel.org> Cc: Stable <stable@vger.kernel.org> # v3.4+
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94f8cc0e |
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16-Apr-2014 |
Frank Rowand <frowand.list@gmail.com> |
drivers/base/dd.c incorrect pr_debug() parameters pr_debug() parameters are reverse order of format string Signed-off-by: Frank Rowand <frank.rowand@sonymobile.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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baab52de |
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06-Nov-2013 |
Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
PM / runtime: Use pm_runtime_put_sync() in __device_release_driver() Commit fa180eb448fa (PM / Runtime: Idle devices asynchronously after probe|release) modified __device_release_driver() to call pm_runtime_put(dev) instead of pm_runtime_put_sync(dev) before detaching the driver from the device. However, that was a mistake, because pm_runtime_put(dev) causes rpm_idle() to be queued up and the driver may be gone already when that function is executed. That breaks the assumptions the drivers have the right to make about the core's behavior on the basis of the existing documentation and actually causes problems to happen, so revert that part of commit fa180eb448fa and restore the previous behavior of __device_release_driver(). Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Fixes: fa180eb448fa (PM / Runtime: Idle devices asynchronously after probe|release) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Kevin Hilman <khilman@linaro.org> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Cc: 3.10+ <stable@vger.kernel.org> # 3.10+
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fa180eb4 |
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10-Apr-2013 |
Ulf Hansson <ulf.hansson@linaro.org> |
PM / Runtime: Idle devices asynchronously after probe|release Putting devices into idle|suspend in a synchronous manner means we are waiting for each device to become idle|suspended before the probe|release is fully done. This patch switch to use the asynchronous runtime PM API:s instead and thus improves the parallelism since we can move on and handle the next device in queue in an earlier phase. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Kevin Hilman <khilman@linaro.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Alan Stern <stern@rowland.harvard.edu> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d72cca1e |
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14-Feb-2013 |
Grant Likely <grant.likely@secretlab.ca> |
drivercore: Fix ordering between deferred_probe and exiting initcalls One of the side effects of deferred probe is that some drivers which used to be probed before initcalls completed are now happening slightly later. This causes two problems. - If a console driver gets deferred, then it may not be ready when userspace starts. For example, if a uart depends on pinctrl, then the uart will get deferred and /dev/console will not be available - __init sections will be discarded before built-in drivers are probed. Strictly speaking, __init functions should not be called in a drivers __probe path, but there are a lot of drivers (console stuff again) that do anyway. In the past it was perfectly safe to do so because all built-in drivers got probed before the end of initcalls. This patch fixes the problem by forcing the first pass of the deferred list to complete at late_initcall time. This is late enough to catch the drivers that are known to have the above issues. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Tested-by: Haojian Zhuang <haojian.zhuang@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable <stable@vger.kernel.org> # 3.4+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ab78029e |
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22-Jan-2013 |
Linus Walleij <linus.walleij@linaro.org> |
drivers/pinctrl: grab default handles from device core This makes the device core auto-grab the pinctrl handle and set the "default" (PINCTRL_STATE_DEFAULT) state for every device that is present in the device model right before probe. This will account for the lion's share of embedded silicon devcies. A modification of the semantics for pinctrl_get() is also done: previously if the pinctrl handle for a certain device was already taken, the pinctrl core would return an error. Now, since the core may have already default-grabbed the handle and set its state to "default", if the handle was already taken, this will be disregarded and the located, previously instanitated handle will be returned to the caller. This way all code in drivers explicitly requesting their pinctrl handlers will still be functional, and drivers that want to explicitly retrieve and switch their handles can still do that. But if the desired functionality is just boilerplate of this type in the probe() function: struct pinctrl *p; p = devm_pinctrl_get_select_default(&dev); if (IS_ERR(p)) { if (PTR_ERR(p) == -EPROBE_DEFER) return -EPROBE_DEFER; dev_warn(&dev, "no pinctrl handle\n"); } The discussion began with the addition of such boilerplate to the omap4 keypad driver: http://marc.info/?l=linux-input&m=135091157719300&w=2 A previous approach using notifiers was discussed: http://marc.info/?l=linux-kernel&m=135263661110528&w=2 This failed because it could not handle deferred probes. This patch alone does not solve the entire dilemma faced: whether code should be distributed into the drivers or if it should be centralized to e.g. a PM domain. But it solves the immediate issue of the addition of boilerplate to a lot of drivers that just want to grab the default state. As mentioned, they can later explicitly retrieve the handle and set different states, and this could as well be done by e.g. PM domains as it is only related to a certain struct device * pointer. ChangeLog v4->v5 (Stephen): - Simplified the devicecore grab code. - Deleted a piece of documentation recommending that pins be mapped to a device rather than hogged. ChangeLog v3->v4 (Linus): - Drop overzealous NULL checks. - Move kref initialization to pinctrl_create(). - Seeking Tested-by from Stephen Warren so we do not disturb the Tegra platform. - Seeking ACK on this from Greg (and others who like it) so I can merge it through the pinctrl subsystem. ChangeLog v2->v3 (Linus): - Abstain from using IS_ERR_OR_NULL() in the driver core, Russell recently sent a patch to remove it. Handle the NULL case explicitly even though it's a bogus case. - Make sure we handle probe deferral correctly in the device core file. devm_kfree() the container on error so we don't waste memory for devices without pinctrl handles. - Introduce reference counting into the pinctrl core using <linux/kref.h> so that we don't release pinctrl handles that have been obtained for two or more places. ChangeLog v1->v2 (Linus): - Only store a pointer in the device struct, and only allocate this if it's really used by the device. Cc: Felipe Balbi <balbi@ti.com> Cc: Benoit Cousson <b-cousson@ti.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: Mitch Bradley <wmb@firmworks.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: Rickard Andersson <rickard.andersson@stericsson.com> Cc: Russell King <linux@arm.linux.org.uk> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> [swarren: fixed and simplified error-handling in pinctrl_bind_pins(), to correctly handle deferred probe. Removed admonition from docs not to use pinctrl hogs for devices] Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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492d5422 |
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09-Jul-2012 |
Dan Williams <dan.j.williams@intel.com> |
[SCSI] cleanup usages of scsi_complete_async_scans Now that scsi registers its async scan work with the async subsystem, wait_for_device_probe() is sufficient for ensuring all scanning is complete. [jejb: fix merge problems with eea03c20ae38 Make wait_for_device_probe() also do scsi_complete_async_scans()] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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eea03c20 |
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18-Jul-2012 |
Linus Torvalds <torvalds@linux-foundation.org> |
Make wait_for_device_probe() also do scsi_complete_async_scans() Commit a7a20d103994 ("sd: limit the scope of the async probe domain") make the SCSI device probing run device discovery in it's own async domain. However, as a result, the partition detection was no longer synchronized by async_synchronize_full() (which, despite the name, only synchronizes the global async space, not all of them). Which in turn meant that "wait_for_device_probe()" would not wait for the SCSI partitions to be parsed. And "wait_for_device_probe()" was what the boot time init code relied on for mounting the root filesystem. Now, most people never noticed this, because not only is it timing-dependent, but modern distributions all use initrd. So the root filesystem isn't actually on a disk at all. And then before they actually mount the final disk filesystem, they will have loaded the scsi-wait-scan module, which not only does the expected wait_for_device_probe(), but also does scsi_complete_async_scans(). [ Side note: scsi_complete_async_scans() had also been partially broken, but that was fixed in commit 43a8d39d0137 ("fix async probe regression"), so that same commit a7a20d103994 had actually broken setups even if you used scsi-wait-scan explicitly ] Solve this problem by just moving the scsi_complete_async_scans() call into wait_for_device_probe(). Everybody who wants to wait for device probing to finish really wants the SCSI probing to complete, so there's no reason not to do this. So now "wait_for_device_probe()" really does what the name implies, and properly waits for device probing to finish. This also removes the now unnecessary extra calls to scsi_complete_async_scans(). Reported-and-tested-by: Artem S. Tashkinov <t.artem@mailcity.com> Cc: Dan Williams <dan.j.williams@gmail.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: James Bottomley <jbottomley@parallels.com> Cc: Borislav Petkov <bp@amd64.org> Cc: linux-scsi <linux-scsi@vger.kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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eed5d215 |
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12-Jul-2012 |
Rafael J. Wysocki <rjw@rjwysocki.net> |
PM / Runtime: Do not increment device usage counts before probing The pm_runtime_get_noresume() calls before really_probe() and before executing __device_attach() for each driver on the device's bus cause problems to happen if probing fails and if the driver has enabled runtime PM for the device in its .probe() callback. Namely, in that case, if the device has been resumed by the driver after enabling its runtime PM and if it turns out that .probe() should return an error, the driver is supposed to suspend the device and disable its runtime PM before exiting .probe(). However, because the device's runtime PM usage counter was incremented by the core before calling .probe(), the driver's attempt to suspend the device will not succeed and the device will remain in the full-power state after the failing .probe() has returned. To fix this issue, remove the pm_runtime_get_noresume() calls from driver_probe_device() and from device_attach() and replace the corresponding pm_runtime_put_sync() calls with pm_runtime_idle() to preserve the existing behavior (which is to check if the device is idle and to suspend it eventually in that case after probing). Reported-and-tested-by: Kevin Hilman <khilman@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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8153584e |
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05-Jul-2012 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
driver core: Move deferred devices to the end of dpm_list before probing When deferred probe was originally added the idea was that devices which defer their probes would move themselves to the end of dpm_list in order to try to keep the assumptions that we're making about the list being in roughly the order things should be suspended correct. However this hasn't been what's been happening and doing it requires a lot of duplicated code to do the moves. Instead take a simple, brute force solution and have the deferred probe code push devices to the end of dpm_list before it retries the probe. This does mean we lock the dpm_list a bit more often but it's very simple and the code shouldn't be a fast path. We do the move with the deferred mutex dropped since doing things with fewer locks held simultaneously seems like a good idea. This approach was most recently suggested by Grant Likely. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Grant Likely <grant.likely@secretlab.ca>, Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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0998d063 |
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22-May-2012 |
Hans de Goede <hdegoede@redhat.com> |
device-core: Ensure drvdata = NULL when no driver is bound 1) drvdata is for a driver to store a pointer to driver specific data 2) If no driver is bound, there is no driver specific data associated with the device 3) Thus logically drvdata should be NULL if no driver is bound. But many drivers don't clear drvdata on device_release, or set drvdata early on in probe and leave it set on probe error. Both of which results in a dangling pointer in drvdata. This patch enforce for drvdata to be NULL after device_release or on probe failure. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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1d29cfa5 |
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29-May-2012 |
Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> |
driver core: fixup reversed deferred probe order If driver requests probe deferral, it will be added to deferred_probe_pending_list by driver_deferred_probe_add(), but, it used list_add(). Because of that, deferred probe will be run as reversed order. This patch uses list_add_tail(), and solved this issue. Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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8b0372a2 |
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08-Mar-2012 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
driver core: minor comment formatting cleanups Came in in the deferred probe patch, quick, clean them up before a kernel janitor finds them and sends me 4 individual patches to fix them up... Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ef8a3fd6 |
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08-Mar-2012 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
driver core: move the deferred probe pointer into the private area Nothing outside of the driver core needs to get to the deferred probe pointer, so move it inside the private area of 'struct device' so no one tries to mess around with it. Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d1c3414c |
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05-Mar-2012 |
Grant Likely <grant.likely@secretlab.ca> |
drivercore: Add driver probe deferral mechanism Allow drivers to report at probe time that they cannot get all the resources required by the device, and should be retried at a later time. This should completely solve the problem of getting devices initialized in the right order. Right now this is mostly handled by mucking about with initcall ordering which is a complete hack, and doesn't even remotely handle the case where device drivers are in modules. This approach completely sidesteps the issues by allowing driver registration to occur in any order, and any driver can request to be retried after a few more other drivers get probed. v4: - Integrate Manjunath's addition of a separate workqueue - Change -EAGAIN to -EPROBE_DEFER for drivers to trigger deferral - Update comment blocks to reflect how the code really works v3: - Hold off workqueue scheduling until late_initcall so that the bulk of driver probes are complete before we start retrying deferred devices. - Tested with simple use cases. Still needs more testing though. Using it to get rid of the gpio early_initcall madness, or to replace the ASoC internal probe deferral code would be ideal. v2: - added locking so it should no longer be utterly broken in that regard - remove device from deferred list at device_del time. - Still completely untested with any real use case, but has been boot tested. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dilan Lee <dilee@nvidia.com> Cc: Manjunath GKondaiah <manjunath.gkondaiah@linaro.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Tony Lindgren <tony@atomide.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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bcbe4f94 |
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20-Sep-2011 |
Wolfram Sang <wsa@kernel.org> |
drivers: base: print rejected matches with DEBUG_DRIVER When DEBUG_DRIVER is activated, be verbose and explicitly state when a device<->driver match was rejected by the probe-function of the driver. Now all code-paths report what is currently happening which helps debugging, because you don't have to remember that no printout means the match is rejected (and then you still don't know if it was because of ENODEV or ENXIO). Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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e1866b33 |
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28-Apr-2011 |
Rafael J. Wysocki <rjw@rjwysocki.net> |
PM / Runtime: Rework runtime PM handling during driver removal The driver core tries to prevent race conditions between runtime PM and driver removal from happening by incrementing the runtime PM usage counter of the device and executing pm_runtime_barrier() before running the bus notifier and the ->remove() callbacks provided by the device's subsystem or driver. This guarantees that, if a future runtime suspend of the device has been scheduled or a runtime resume or idle request has been queued up right before the driver removal, it will be canceled or waited for to complete and no other asynchronous runtime suspend or idle requests for the device will be put into the PM workqueue until the ->remove() callback returns. However, it doesn't prevent resume requests from being queued up after pm_runtime_barrier() has been called and it doesn't prevent pm_runtime_resume() from executing the device subsystem's runtime resume callback. Morever, it prevents the device's subsystem or driver from putting the device into the suspended state by calling pm_runtime_suspend() from its ->remove() routine. This turns out to be a major inconvenience for some subsystems and drivers that want to leave the devices they handle in the suspended state. To really prevent runtime PM callbacks from racing with the bus notifier callback in __device_release_driver(), which is necessary, because the notifier is used by some subsystems to carry out operations affecting the runtime PM functionality, use pm_runtime_get_sync() instead of the combination of pm_runtime_get_noresume() and pm_runtime_barrier(). This will resume the device if it's in the suspended state and will prevent it from being suspended again until pm_runtime_put_*() is called. To allow subsystems and drivers to put devices into the suspended state by calling pm_runtime_suspend() from their ->remove() routines, execute pm_runtime_put_sync() after running the bus notifier in __device_release_driver(). This will require subsystems and drivers to make their ->remove() callbacks avoid races with runtime PM directly, but it will allow of more flexibility in the handling of devices during the removal of their drivers. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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c8705082 |
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20-Apr-2011 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
driver core: let dev_set_drvdata return int instead of void as it can fail Before commit b402843 (Driver core: move dev_get/set_drvdata to drivers/base/dd.c) calling dev_set_drvdata with dev=NULL was an unchecked error. After some discussion about what to return in this case removing the check (and so producing a null pointer exception) seems fine. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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8497d6a2 |
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12-Apr-2011 |
Sebastian Ott <sebott@linux.vnet.ibm.com> |
driver-core: fix race between device_register and driver_register When a device is registered to a bus it will be a) added to the list of devices of the bus and b) bind to a driver (if one matches). As a result of a driver being registered at this bus between a) and b) this device could already be bound to a driver. This leads to a warning and incorrect refcounting. To fix this add a check to device_attach to identify an already bound device. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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45daef0f |
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23-Jul-2010 |
Magnus Damm <damm@opensource.se> |
Driver core: Add BUS_NOTIFY_BIND_DRIVER Add BUS_NOTIFY_BIND_DRIVER as a bus notifier event. For driver binding/unbinding we with this in place have the following bus notifier events: - BUS_NOTIFY_BIND_DRIVER - before ->probe() - BUS_NOTIFY_BOUND_DRIVER - after ->probe() - BUS_NOTIFY_UNBIND_DRIVER - before ->remove() - BUS_NOTIFY_UNBOUND_DRIVER - after ->remove() The event BUS_NOTIFY_BIND_DRIVER allows bus code to be notified that ->probe() is about to be called. Useful for bus code that needs to setup hardware before the driver gets to run. With this in place platform drivers can be loaded and unloaded as modules and the new BIND event allows bus code to control for instance device clocks that must be enabled before the driver can be executed. Without this patch there is no way for the bus code to get notified that a modular driver is about to be probed. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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fbb88fad |
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06-Mar-2010 |
Stefani Seibold <stefani@seibold.net> |
driver-core: fix potential race condition in drivers/base/dd.c This patch fix a potential race condition in the driver_bound() function in the file driver/base/dd.c. The broadcast of the BUS_NOTIFY_BOUND_DRIVER notifier should be done after adding the new device to the driver list. Otherwise notifier listener will fail if they use functions like usb_find_interface(). The patch is against kernel 2.6.33. Please merge it. Signed-off-by: Stefani Seibold <stefani@seibold.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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8e9394ce |
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17-Feb-2010 |
Greg Kroah-Hartman <gregkh@suse.de> |
Driver core: create lock/unlock functions for struct device In the future, we are going to be changing the lock type for struct device (once we get the lockdep infrastructure properly worked out) To make that changeover easier, and to possibly burry the lock in a different part of struct device, let's create some functions to lock and unlock a device so that no out-of-core code needs to be changed in the future. This patch creates the device_lock/unlock/trylock() functions, and converts all in-tree users to them. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jean Delvare <khali@linux-fr.org> Cc: Dave Young <hidave.darkstar@gmail.com> Cc: Ming Lei <tom.leiming@gmail.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Phil Carmody <ext-phil.2.carmody@nokia.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Cc: Len Brown <len.brown@intel.com> Cc: Magnus Damm <damm@igel.co.jp> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Alex Chiang <achiang@hp.com> Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrew Patterson <andrew.patterson@hp.com> Cc: Yu Zhao <yu.zhao@intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Wolfram Sang <w.sang@pengutronix.de> Cc: CHENG Renquan <rqcheng@smu.edu.sg> Cc: Oliver Neukum <oliver@neukum.org> Cc: Frans Pop <elendil@planet.nl> Cc: David Vrabel <david.vrabel@csr.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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af901ca1 |
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14-Nov-2009 |
André Goddard Rosa <andre.goddard@gmail.com> |
tree-wide: fix assorted typos all over the place That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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b4028437 |
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11-May-2009 |
Greg Kroah-Hartman <gregkh@suse.de> |
Driver core: move dev_get/set_drvdata to drivers/base/dd.c No one should directly access the driver_data field, so remove the field and make it private. We dynamically create the private field now if it is needed, to handle drivers that call get/set before they are registered with the driver core. Also update the copyright notices on these files while we are there. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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5e928f77 |
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18-Aug-2009 |
Rafael J. Wysocki <rjw@rjwysocki.net> |
PM: Introduce core framework for run-time PM of I/O devices (rev. 17) Introduce a core framework for run-time power management of I/O devices. Add device run-time PM fields to 'struct dev_pm_info' and device run-time PM callbacks to 'struct dev_pm_ops'. Introduce a run-time PM workqueue and define some device run-time PM helper functions at the core level. Document all these things. Special thanks to Alan Stern for his help with the design and multiple detailed reviews of the pereceding versions of this patch and to Magnus Damm for testing feedback. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Magnus Damm <damm@igel.co.jp>
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#
59a3cd7f |
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05-May-2009 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
Driver core: fix comment for device_attach() We are looking for matching drivers, not devices. Signed-off-by: Dmitry Torokhov <dtor@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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309b7d60 |
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24-Apr-2009 |
Joerg Roedel <joerg.roedel@amd.com> |
driver core: add BUS_NOTIFY_UNBOUND_DRIVER event This patch adds a new bus notifier event which is emitted _after_ a device is removed from its driver. This event will be used by the dma-api debug code to check if a driver has released all dma allocations for that device. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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d4d5291c |
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21-Apr-2009 |
Arjan van de Ven <arjan@linux.intel.com> |
driver synchronization: make scsi_wait_scan more advanced There is currently only one way for userspace to say "wait for my storage device to get ready for the modules I just loaded": to load the scsi_wait_scan module. Expectations of userspace are that once this module is loaded, all the (storage) devices for which the drivers were loaded before the module load are present. Now, there are some issues with the implementation, and the async stuff got caught in the middle of this: The existing code only waits for the scsy async probing to finish, but it did not take into account at all that probing might not have begun yet. (Russell ran into this problem on his computer and the fix works for him) This patch fixes this more thoroughly than the previous "fix", which had some bad side effects (namely, for kernel code that wanted to wait for the scsi scan it would also do an async sync, which would deadlock if you did it from async context already.. there's a report about that on lkml): The patch makes the module first wait for all device driver probes, and then it will wait for the scsi parallel scan to finish. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Tested-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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8940b4f3 |
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16-Dec-2008 |
Greg Kroah-Hartman <gregkh@suse.de> |
driver core: move knode_driver into private structure Nothing outside of the driver core should ever touch knode_driver, so move it out of the public eye. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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b23530eb |
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21-Feb-2009 |
Ming Lei <tom.leiming@gmail.com> |
driver core: remove polling for driver_probe_done(v5) This patch removes 100ms polling for driver_probe_done in wait_for_device_probe(), and uses wait_event() instead. Removing polling in fs initialization may lead to a faster boot. This patch also changes the return type of wait_for_device_done() from int to void. This patch is against Arjan's patch in linux-next tree. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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49b420a1 |
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21-Jan-2009 |
Ming Lei <tom.leiming@gmail.com> |
driver core: check bus->match without holding device lock This patch moves bus->match out from driver_probe_device and does not hold device lock to check the match between a device and a driver. The idea has been verified by the commit 6cd495860901, which leads to a faster boot. But the commit 6cd495860901 has the following drawbacks: 1),only does the quick check in the path of __driver_attach->driver_probe_device, not in other paths; 2),for a matched device and driver, check the same match twice. It is a waste of cpu ,especially for some drivers with long device id table (eg. usb-storage driver). This patch adds a helper of driver_match_device to check the match in all paths, and testes the match only once. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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216773a7 |
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13-Feb-2009 |
Arjan van de Ven <arjan@linux.intel.com> |
Consolidate driver_probe_done() loops into one place there's a few places that currently loop over driver_probe_done(), and I'm about to add another one. This patch abstracts it into a helper to reduce duplication. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Acked-by: Greg KH <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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cda5e83f |
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09-Jan-2009 |
Greg Kroah-Hartman <gregkh@suse.de> |
Revert "driver core: move knode_driver into private structure" This reverts commit 93e746db183b3bdbbda67900f79b5835f9cb388f. Turns out that device_initialize shouldn't fail silently. This series needs to be reworked in order to get into proper shape. Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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7232800b |
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17-Dec-2008 |
Ming Lei <tom.leiming@gmail.com> |
driver core:fix duplicate removing driver link in __device_release_driver In __device_release_driver(),driver_sysfs_remove() has removed the driver link under device dir in sysfs, but sysfs_remove_link() is called again to do such thing. Remove the duplicate call to sys_remove_link(). Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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93e746db |
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16-Dec-2008 |
Greg Kroah-Hartman <gregkh@suse.de> |
driver core: move knode_driver into private structure Nothing outside of the driver core should ever touch knode_driver, so move it out of the public eye. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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1e0b2cf9 |
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29-Oct-2008 |
Kay Sievers <kay.sievers@vrfy.org> |
driver core: struct device - replace bus_id with dev_name(), dev_set_name() Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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6cd49586 |
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14-Sep-2008 |
Arjan van de Ven <arjan@linux.intel.com> |
device model: Do a quickcheck for driver binding before doing an expensive check This patch adds a quick check for the driver<->device match before taking the locks and doin gthe expensive checks. Taking the lock hurts in asynchronous boot context where the device lock gets hit; one of the init functions takes the lock and goes to do an expensive hardware init; the other init functions walk the same PCI list and get stuck on the lock as a result. For the common case, we can know there's no chance whatsoever of a match if the device isn't in the drivers ID table... so this patch does that check as a best-effort-avoid-the-lock approach. Bootcharts for before and after can be seen at http://www.fenrus.org/before.svg http://www.fenrus.org/after.svg Note the long time "agp_ali_init" takes in the first graph; my laptop doesn't even have an ALI chip in it! (the bootgraphs look a bit dissimilar, but that's the point, the first one has a bunch of arbitrary delays in it that cause it to look very different) This reduces my kernel boot time by about 20% Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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2b3a302a |
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04-Mar-2008 |
Harvey Harrison <harvey.harrison@gmail.com> |
driver core: replace remaining __FUNCTION__ occurrences __FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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4a3ad20c |
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24-Jan-2008 |
Greg Kroah-Hartman <gregkh@suse.de> |
Driver core: coding style fixes Fix up a number of coding style issues in the drivers/base/ directory that have annoyed me over the years. checkpatch.pl is now very happy. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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ef2c5174 |
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16-Nov-2007 |
Alan Stern <stern@rowland.harvard.edu> |
Driver core: fix race in __device_release_driver This patch (as1013) was suggested by David Woodhouse; it fixes a race in the driver core. If a device is unregistered at the same time as its driver is unloaded, the driver's code pages may be unmapped while the remove method is still running. The calls to get_driver() and put_driver() were intended to prevent this, but they don't work if the driver's module count has already dropped to 0. Instead, the patch keeps the device on the driver's list until after the remove method has returned. This forces the necessary synchronization to occur. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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7dc72b28 |
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29-Nov-2007 |
Greg Kroah-Hartman <gregkh@suse.de> |
Driver core: clean up debugging messages The driver core debugging messages are a mess. This provides a unified message that makes them actually useful. The format for new kobject debug messages should be: driver/bus/class: 'OBJECT_NAME': FUNCTION_NAME: message.\n Note, the class code is not changed in this patch due to pending patches in my queue that this would conflict with. A later patch will clean them up. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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e5dd1278 |
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28-Nov-2007 |
Greg Kroah-Hartman <gregkh@suse.de> |
Driver core: move the static kobject out of struct driver This patch removes the kobject, and a few other driver-core-only fields out of struct driver and into the driver core only. Now drivers can be safely create on the stack or statically (like they currently are.) Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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c6f7e72a |
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01-Nov-2007 |
Greg Kroah-Hartman <gregkh@suse.de> |
driver core: remove fields from struct bus_type struct bus_type is static everywhere in the kernel. This moves the kobject in the structure out of it, and a bunch of other private only to the driver core fields are now moved to a private structure. This lets us dynamically create the backing kobject properly and gives us the chance to be able to document to users exactly how to use the struct bus_type as there are no fields they can improperly access. Thanks to Kay for the build fixes on this patch. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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ab71c6f0 |
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17-Jun-2007 |
Stefan Richter <stefanr@s5r6.in-berlin.de> |
driver core: fix kernel doc of device_release_driver Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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1f5681aa |
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17-Jun-2007 |
Stefan Richter <stefanr@s5r6.in-berlin.de> |
driver core: properly get driver in device_release_driver Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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475c5a15 |
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08-May-2007 |
Stephen Hemminger <shemminger@linux-foundation.org> |
Driver core: kill unused code CC drivers/base/dd.o drivers/base/dd.c:211: warning: =E2=80=98device_probe_drivers=E2=80=99 defi= ned but not used Looks like the following is dead. Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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5adc55da |
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26-Mar-2007 |
Adrian Bunk <bunk@stusta.de> |
PCI: remove the broken PCI_MULTITHREAD_PROBE option This patch removes the PCI_MULTITHREAD_PROBE option that had already been marked as broken. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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c6a46696 |
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05-Feb-2007 |
Cornelia Huck <cornelia.huck@de.ibm.com> |
driver core: don't fail attaching the device if it cannot be bound Don't fail bus_attach_device() if the device cannot be bound. If dev->driver has been specified, reset it to NULL if device_bind_driver() failed and add the device as an unbound device. As a result, bus_attach_device() now cannot fail, and we can remove some checking from device_add(). Also remove an unneeded check in bus_rescan_devices_helper(). Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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21c7f30b |
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05-Feb-2007 |
Cornelia Huck <cornelia.huck@de.ibm.com> |
driver core: per-subsystem multithreaded probing Make multithreaded probing work per subsystem instead of per driver. It doesn't make much sense to probe the same device for multiple drivers in parallel (after all, only one driver can bind to the device). Instead, create a probing thread for each device that probes the drivers one after another. Also make the decision to use multi-threaded probe per bus instead of per device and adapt the pci code. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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9ac7849e |
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20-Jan-2007 |
Tejun Heo <htejun@gmail.com> |
devres: device resource management Implement device resource management, in short, devres. A device driver can allocate arbirary size of devres data which is associated with a release function. On driver detach, release function is invoked on the devres data, then, devres data is freed. devreses are typed by associated release functions. Some devreses are better represented by single instance of the type while others need multiple instances sharing the same release function. Both usages are supported. devreses can be grouped using devres group such that a device driver can easily release acquired resources halfway through initialization or selectively release resources (e.g. resources for port 1 out of 4 ports). This patch adds devres core including documentation and the following managed interfaces. * alloc/free : devm_kzalloc(), devm_kzfree() * IO region : devm_request_region(), devm_release_region() * IRQ : devm_request_irq(), devm_free_irq() * DMA : dmam_alloc_coherent(), dmam_free_coherent(), dmam_declare_coherent_memory(), dmam_pool_create(), dmam_pool_destroy() * PCI : pcim_enable_device(), pcim_pin_device(), pci_is_managed() * iomap : devm_ioport_map(), devm_ioport_unmap(), devm_ioremap(), devm_ioremap_nocache(), devm_iounmap(), pcim_iomap_table(), pcim_iomap(), pcim_iounmap() Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
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cb986b74 |
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27-Nov-2006 |
Cornelia Huck <cornelia.huck@de.ibm.com> |
driver core: Change function call order in device_bind_driver(). Change function call order in device_bind_driver(). If we create symlinks (which might fail) before adding the device to the list we don't have to clean up afterwards (which we didn't). Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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c578abbc |
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27-Nov-2006 |
Cornelia Huck <cornelia.huck@de.ibm.com> |
driver core: Don't stop probing on ->probe errors. Don't stop on the first ->probe error that is not -ENODEV/-ENXIO. There might be a driver registered returning an unresonable return code, and this stops probing completely even though it may make sense to try the next possible driver. At worst, we may end up with an unbound device. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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1901fb26 |
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07-Oct-2006 |
Kay Sievers <kay.sievers@novell.com> |
Driver core: fix "driver" symlink timing Create the "driver" link before the child device may be created by the probing logic. This makes it possible for userspace (udev), to determine the driver property of the parent device, at the time the child device is created. Signed-off-by: Kay Sievers <kay.sievers@novell.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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116af378 |
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24-Oct-2006 |
Benjamin Herrenschmidt <benh@kernel.crashing.org> |
Driver core: add notification of bus events I finally did as you suggested and added the notifier to the struct bus_type itself. There are still problems to be expected is something attaches to a bus type where the code can hook in different struct device sub-classes (which is imho a big bogosity but I won't even try to argue that case now) but it will solve nicely a number of issues I've had so far. That also means that clients interested in registering for such notifications have to do it before devices are added and after bus types are registered. Fortunately, most bus types that matter for the various usage scenarios I have in mind are registerd at postcore_initcall time, which means I have a really nice spot at arch_initcall time to add my notifiers. There are 4 notifications provided. Device being added (before hooked to the bus) and removed (failure of previous case or after being unhooked from the bus), along with driver being bound to a device and about to be unbound. The usage I have for these are: - The 2 first ones are used to maintain a struct device_ext that is hooked to struct device.firmware_data. This structure contains for now a pointer to the Open Firmware node related to the device (if any), the NUMA node ID (for quick access to it) and the DMA operations pointers & iommu table instance for DMA to/from this device. For bus types I own (like IBM VIO or EBUS), I just maintain that structure directly from the bus code when creating the devices. But for bus types managed by generic code like PCI or platform (actually, of_platform which is a variation of platform linked to Open Firmware device-tree), I need this notifier. - The other two ones have a completely different usage scenario. I have cases where multiple devices and their drivers depend on each other. For example, the IBM EMAC network driver needs to attach to a MAL DMA engine which is a separate device, and a PHY interface which is also a separate device. They are all of_platform_device's (well, about to be with my upcoming patches) but there is no say in what precise order the core will "probe" them and instanciate the various modules. The solution I found for that is to have the drivers for emac to use multithread_probe, and wait for a driver to be bound to the target MAL and PHY control devices (the device-tree contains reference to the MAL and PHY interface nodes, which I can then match to of_platform_devices). Right now, I've been polling, but with that notifier, I can more cleanly wait (with a timeout of course). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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735a7ffb |
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27-Oct-2006 |
Andrew Morton <akpm@osdl.org> |
[PATCH] drivers: wait for threaded probes between initcall levels The multithreaded-probing code has a problem: after one initcall level (eg, core_initcall) has been processed, we will then start processing the next level (postcore_initcall) while the kernel threads which are handling core_initcall are still executing. This breaks the guarantees which the layered initcalls previously gave us. IOW, we want to be multithreaded _within_ an initcall level, but not between different levels. Fix that up by causing the probing code to wait for all outstanding probes at one level to complete before we start processing the next level. Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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4d664238 |
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09-Oct-2006 |
Akinobu Mita <akinobu.mita@gmail.com> |
driver core: kmalloc() failure check in driver_probe_device driver_probe_device() is missing kmalloc() failure check. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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0fbf116d |
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27-Sep-2006 |
Duncan Sands <duncan.sands@free.fr> |
Driver core: plug device probe memory leak Make sure data is freed if the kthread fails to start. Signed-off-by: Duncan Sands <baldrick@free.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
f2eaae19 |
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18-Sep-2006 |
Alan Stern <stern@rowland.harvard.edu> |
Driver core: Fix potential deadlock in driver core There is a potential deadlock in the driver core. It boils down to the fact that bus_remove_device() calls klist_remove() instead of klist_del(), thereby waiting until the reference count of the klist_node in the bus's klist of devices drops to 0. The refcount can't reach 0 so long as a modprobe process is trying to bind a new driver to the device being removed, by calling __driver_attach(). The problem is that __driver_attach() tries to acquire the device's parent's semaphore, but the caller of bus_remove_device() is quite likely to own that semaphore already. It isn't sufficient just to replace klist_remove() with klist_del(). Doing so runs the risk that the device would remain on the bus's klist of devices for some time, and so could be bound to another driver even after it was unregistered. What's needed is a new way to distinguish whether or not a device is registered, based on a criterion other than whether its klist_node is linked into the bus's klist of devices. That way driver binding can fail when the device is unregistered, even if it is still linked into the klist. This patch (as782) implements the solution, by adding a new bitflag to indiate when a struct device is registered, by testing the flag before allowing a driver to bind a device, and by changing the definition of the device_is_registered() inline. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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d779249e |
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18-Jul-2006 |
Greg Kroah-Hartman <gregkh@suse.de> |
Driver Core: add ability for drivers to do a threaded probe This adds the infrastructure for drivers to do a threaded probe, and waits at init time for all currently outstanding probes to complete. A new kernel thread will be created when the probe() function for the driver is called, if the multithread_probe bit is set in the driver saying it can support this kind of operation. I have tested this with USB and PCI, and it works, and shaves off a lot of time in the boot process, but there are issues with finding root boot disks, and some USB drivers assume that this can never happen, so it is currently not enabled for any bus type. Individual drivers can enable this right now if they wish, and bus authors can selectivly turn it on as well, once they determine that their subsystem will work properly with it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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f86db396 |
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14-Aug-2006 |
Andrew Morton <akpm@osdl.org> |
drivers/base: check errors Add lots of return-value checking. <pcornelia.huck@de.ibm.com>: fix bus_rescan_devices()] Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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0f836ca4 |
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31-Mar-2006 |
Alan Stern <stern@rowland.harvard.edu> |
[PATCH] driver core: safely unbind drivers for devices not on a bus This patch (as667) changes the __device_release_driver() routine to prevent it from crashing when it runs across a device not on any bus. This seems logical, inasmuch as the corresponding bus_add_device() routine has an explicit check allowing it to accept such devices. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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594c8281 |
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05-Jan-2006 |
Russell King <rmk@arm.linux.org.uk> |
[PATCH] Add bus_type probe, remove, shutdown methods. Add bus_type probe, remove and shutdown methods to replace the corresponding methods in struct device_driver. This matches the way we handle the suspend/resume methods. Since the bus methods override the device_driver methods, warn if a device driver is registered whose methods will not be called. The long-term idea is to remove the device_driver methods entirely. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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bf74ad5b |
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17-Nov-2005 |
Alan Stern <stern@rowland.harvard.edu> |
[PATCH] Hold the device's parent's lock during probe and remove This patch (as604) makes the driver core hold a device's parent's lock as well as the device's lock during calls to the probe and remove methods in a driver. This facility is needed by USB device drivers, owing to the peculiar way USB devices work: A device provides multiple interfaces, and drivers are bound to interfaces rather than to devices; Nevertheless a reset, reset-configuration, suspend, or resume affects the entire device and requires the caller to hold the lock for the device, not just a lock for one of the interfaces. Since a USB driver's probe method is always called with the interface lock held, the locking order rules (always lock parent before child) prevent these methods from acquiring the device lock. The solution provided here is to call all probe and remove methods, for all devices (not just USB), with the parent lock already acquired. Although currently only the USB subsystem requires these changes, people have mentioned in prior discussion that the overhead of acquiring an extra semaphore in all the prove/remove sequences is not overly large. Up to now, the USB core has been using its own set of private semaphores. A followup patch will remove them, relying entirely on the device semaphores provided by the driver core. The code paths affected by this patch are: device_add and device_del: The USB core already holds the parent lock, so no actual change is needed. driver_register and driver_unregister: The driver core will now lock both the parent and the device before probing or removing. driver_bind and driver_unbind (in sysfs): These routines will now lock both the parent and the device before binding or unbinding. bus_rescan_devices: The helper routine will lock the parent before probing a device. I have not tested this patch for conflicts with other subsystems. As far as I can see, the only possibility of conflict would lie in the bus_rescan_devices pathway, and it seems pretty remote. Nevertheless, it would be good for this to get a lot of testing in -mm. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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2b08c8d0 |
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23-Nov-2005 |
Alan Stern <stern@rowland.harvard.edu> |
[PATCH] Small fixes to driver core This patch (as603) makes a few small fixes to the driver core: Change spin_lock_irq for a klist lock to spin_lock; Fix reference count leaks; Minor spelling and formatting changes. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by Patrick Mochel <mochel@digitalimplant.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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4c898c7f |
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22-Sep-2005 |
Daniel Ritz <daniel.ritz@gmx.ch> |
[PATCH] Driver Core: fis bus rescan devices race bus_rescan_devices_helper() does not hold the dev->sem when it checks for !dev->driver(). device_attach() holds the sem, but calls again device_bind_driver() even when dev->driver is set. What happens is that a first device_attach() call (module insertion time) is on the way binding the device to a driver. Another thread calls bus_rescan_devices(). Now when bus_rescan_devices_helper() checks for dev->driver it is still NULL 'cos the the prior device_attach() is not yet finished. But as soon as the first one releases the dev->sem the second device_attach() tries to rebind the already bound device again. device_bind_driver() does this blindly which leads to a corrupt driver->klist_devices list (the device links itself, the head points to the device). Later a call to device_release_driver() sets dev->driver to NULL and breaks the link it has to itself on knode_driver. Rmmoding the driver later calls driver_detach() which leads to an endless loop 'cos the list head in klist_devices still points to the device. And since dev->driver is NULL it's stuck with the same device forever. Boom. And rmmod hangs. Very easy to reproduce with new-style pcmcia and a 16bit card. Just loop modprobe <pcmcia-modules> ;cardctl eject; rmmod <card driver, pcmcia modules>. Easiest fix is to check if the device is already bound to a driver in device_bind_driver(). This avoids the double binding. Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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d856f1e3 |
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19-Aug-2005 |
James Bottomley <James.Bottomley@SteelEye.com> |
[PATCH] klist: fix klist to have the same klist_add semantics as list_head at the moment, the list_head semantics are list_add(node, head) whereas current klist semantics are klist_add(head, node) This is bound to cause confusion, and since klist is the newcomer, it should follow the list_head semantics. I also added missing include guards to klist.h Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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afdce75f |
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22-Jun-2005 |
Greg Kroah-Hartman <gregkh@suse.de> |
[PATCH] driver core: Add the ability to bind drivers to devices from userspace This adds a single file, "bind", to the sysfs directory of every driver registered with the driver core. To bind a device to a driver, write the bus id of the device you wish to bind to that specific driver to the "bind" file (remember to not add a trailing \n). If that bus id matches a device on that bus, and it does not currently have a driver bound to it, the probe sequence will be initiated with that driver and device. Note, this requires that the driver itself be willing and able to accept that device (usually through a device id type table). This patch does not make it possible to override the driver's id table. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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ca2b94ba |
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18-May-2005 |
Hannes Reinecke <hare@suse.de> |
[PATCH] driver core: fix error handling in bus_add_device The error handling in bus_add_device() and device_attach() is simply non-existing. This patch propagates any error from device_attach to the upper layers to allow for a proper recovery. From: Hannes Reinecke <hare@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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c95a6b05 |
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06-May-2005 |
Alan Stern <stern@rowland.harvard.edu> |
[PATCH] driver core: Fix races in driver_detach() This patch is intended for your "driver" tree. It fixes several subtle races in driver_detach() and device_release_driver() in the driver-model core. The major change is to use klist_remove() rather than klist_del() when taking a device off its driver's list. There's no other way to guarantee that the list pointers will be updated before some other driver binds to the device. For this to work driver_detach() can't use a klist iterator, so the loop over the devices must be written out in full. In addition the patch protects against the possibility that, when a driver and a device are unregistered at the same time, one may be unloaded from memory before the other is finished using it. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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0d3e5a2e |
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06-Apr-2005 |
Patrick Mochel <mochel@digitalimplant.org> |
[PATCH] Driver Core: fix bk-driver-core kills ppc64 There's no check to see if the device is already bound to a driver, which could do bad things. The first thing to go wrong is that it will try to match a driver with a device already bound to one. In some cases (it appears with USB with drivers/usb/core/usb.c::usb_match_id()), some drivers will match a device based on the class type, so it would be common (especially for HID devices) to match a device that is already bound. The fun comes when ->probe() is called, it fails, then driver_probe_device() does this: dev->driver = NULL; Later on, that pointer could be be dereferenced without checking and cause hell to break loose. This problem could be nasty. It's very hardware dependent, since some devices could have a different set of matching qualifiers than others. Now, I don't quite see exactly where/how you were getting that crash. You're dereferencing bad memory, but I'm not sure which pointer was bad and where it came from, but it could have come from a couple of different places. The patch below will hopefully fix it all up for you. It's against 2.6.12-rc2-mm1, and does the following: - Move logic to driver_probe_device() and comments uncommon returns: 1 - If device is bound 0 - If device not bound, and no error error - If there was an error. - Move locking to caller of that function, since we want to lock a device for the entire time we're trying to bind it to a driver (to prevent against a driver being loaded at the same time). - Update __device_attach() and __driver_attach() to do that locking. - Check if device is already bound in __driver_attach() - Update the converse device_release_driver() so it locks the device around all of the operations. - Mark driver_probe_device() as static and remove export. It's an internal function, it should stay that way, and there are no other callers. If there is ever a need to export it, we can audit it as necessary. Signed-off-by: Andrew Morton <akpm@osdl.org>
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b86c1df1 |
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31-Mar-2005 |
Greg Kroah-Hartman <gregkh@suse.de> |
[PATCH] Driver core: Fix up the driver and device iterators to be quieter Also stops looping over the lists when a match is found. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de
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0956af53 |
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24-Mar-2005 |
Patrick Mochel <mochel@digitalimplant.org> |
[PATCH] Call klist_del() instead of klist_remove(). - Can't wait on removing the current item in the list (the positive refcount *because* we are using it causes it to deadlock). Signed-off-by: Patrick Mochel <mochel@digitalimplant.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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2287c322 |
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24-Mar-2005 |
Patrick Mochel <mochel@digitalimplant.org> |
[PATCH] Use bus_for_each_{dev,drv} for driver binding. - Now possible, since the lists are locked using the klist lock and not the global rwsem. Signed-off-by: Patrick Mochel <mochel@digitalimplant.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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94e7b1c5 |
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21-Mar-2005 |
Patrick Mochel <mochel@digitalimplant.org> |
[PATCH] Add a klist to struct device_driver for the devices bound to it. - Use it in driver_for_each_device() instead of the regular list_head and stop using the bus's rwsem for protection. - Use driver_for_each_device() in driver_detach() so we don't deadlock on the bus's rwsem. - Remove ->devices. - Move klist access and sysfs link access out from under device's semaphore, since they're synchronized through other means. Signed-off-by: Patrick Mochel <mochel@digitalimplant.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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07e4a3e2 |
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21-Mar-2005 |
Patrick Mochel <mochel@digitalimplant.org> |
[PATCH] Move device/driver code to drivers/base/dd.c This relocates the driver binding/unbinding code to drivers/base/dd.c. This is done for two reasons: One, it's not code related to the bus_type itself; it uses some from that, some from devices, and some from drivers. And Two, it will make it easier to do some of the upcoming lock removal on that code.. Signed-off-by: Patrick Mochel <mochel@digitalimplant.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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