linux/drivers/base/dd.c, branch v5.9

driver core: add deferring probe reason to devices_deferred property

2020-07-30T07:03:43Z

/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 Reviewed-by: Mark Brown Reviewed-by: Javier Martinez Canillas Reviewed-by: Andy Shevchenko Reviewed-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20200713144324.23654-3-a.hajda@samsung.com Signed-off-by: Greg Kroah-Hartman

driver core: Avoid binding drivers to dead devices

2020-07-30T06:48:34Z

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 Cc: stable@vger.kernel.org # v5.1+ Cc: Alexander Duyck Link: https://lore.kernel.org/r/de88a23a6fe0ef70f7cfd13c8aea9ab51b4edab6.1594214103.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

driver core: Fix probe_count imbalance in really_probe()

2020-07-23T13:21:28Z

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 Fixes: 7c35e699c88bd607 ("driver core: Print device when resources present in really_probe()") Cc: Geert Uytterhoeven Signed-off-by: Tetsuo Handa Cc: stable Link: https://lore.kernel.org/r/20200713021254.3444-1-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Greg Kroah-Hartman

Merge 5.8-rc6 into driver-core-next

2020-07-20T07:31:35Z

We need the driver core fixes in here too. Signed-off-by: Greg Kroah-Hartman

driver core: Add state_synced sysfs file for devices that support it

2020-07-10T13:24:56Z

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 Link: https://lore.kernel.org/r/20200521191800.136035-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver core: Don't do deferred probe in parallel with kernel_init thread

2020-07-10T13:20:38Z

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 Tested-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20200701194259.3337652-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver core: Drop mention of obsolete bus rwsem from kernel-doc

2020-07-10T13:13:43Z

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 Link: https://lore.kernel.org/r/b1af31b0e351bcbc056fe1ec44500737a7998d43.1594210157.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

driver core: Remove check in driver_deferred_probe_force_trigger()

2020-05-19T14:48:23Z

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 Link: https://lore.kernel.org/r/20200517173453.157703-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver core: fw_devlink: Add support for batching fwnode parsing

2020-05-15T14:34:52Z

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 Link: https://lore.kernel.org/r/20200515053500.215929-4-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

Merge v5.7-rc5 into driver-core-next

2020-05-11T07:00:09Z

We want the driver core fixes in here and this resolves a merge issue with drivers/base/dd.c Signed-off-by: Greg Kroah-Hartman