user/sven/linux.git/drivers/base/power, branch v4.14.238

Revert "PM: runtime: Update device status before letting suppliers suspend"

2021-03-24T10:04:55Z

commit 0cab893f409c53634d0d818fa414641cbcdb0dab upstream. Revert commit 44cc89f76464 ("PM: runtime: Update device status before letting suppliers suspend") that introduced a race condition into __rpm_callback() which allowed a concurrent rpm_resume() to run and resume the device prematurely after its status had been changed to RPM_SUSPENDED by __rpm_callback(). Fixes: 44cc89f76464 ("PM: runtime: Update device status before letting suppliers suspend") Link: https://lore.kernel.org/linux-pm/24dfb6fc-5d54-6ee2-9195-26428b7ecf8a@intel.com/ Reported-by: Adrian Hunter Cc: 4.10+ # 4.10+ Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman

PM: runtime: Update device status before letting suppliers suspend

2021-03-11T12:51:04Z

commit 44cc89f764646b2f1f2ea5d1a08b230131707851 upstream. Because the PM-runtime status of the device is not updated in __rpm_callback(), attempts to suspend the suppliers of the given device triggered by rpm_put_suppliers() called by it may fail. Fix this by making __rpm_callback() update the device's status to RPM_SUSPENDED before calling rpm_put_suppliers() if the current status of the device is RPM_SUSPENDING and the callback just invoked by it has returned 0 (success). While at it, modify the code in __rpm_callback() to always check the device's PM-runtime status under its PM lock. Link: https://lore.kernel.org/linux-pm/CAPDyKFqm06KDw_p8WXsM4dijDbho4bb6T4k50UqqvR1_COsp8g@mail.gmail.com/ Fixes: 21d5c57b3726 ("PM / runtime: Use device links") Reported-by: Elaine Zhang Diagnosed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki Tested-by: Elaine Zhang Reviewed-by: Ulf Hansson Cc: 4.10+ # 4.10+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM: sleep: core: Fix the handling of pending runtime resume requests

2020-09-03T09:22:32Z

commit e3eb6e8fba65094328b8dca635d00de74ba75b45 upstream. It has been reported that system-wide suspend may be aborted in the absence of any wakeup events due to unforseen interactions of it with the runtume PM framework. One failing scenario is when there are multiple devices sharing an ACPI power resource and runtime-resume needs to be carried out for one of them during system-wide suspend (for example, because it needs to be reconfigured before the whole system goes to sleep). In that case, the runtime-resume of that device involves turning the ACPI power resource "on" which in turn causes runtime-resume requests to be queued up for all of the other devices sharing it. Those requests go to the runtime PM workqueue which is frozen during system-wide suspend, so they are not actually taken care of until the resume of the whole system, but the pm_runtime_barrier() call in __device_suspend() sees them and triggers system wakeup events for them which then cause the system-wide suspend to be aborted if wakeup source objects are in active use. Of course, the logic that leads to triggering those wakeup events is questionable in the first place, because clearly there are cases in which a pending runtime resume request for a device is not connected to any real wakeup events in any way (like the one above). Moreover, it is racy, because the device may be resuming already by the time the pm_runtime_barrier() runs and so if the driver doesn't take care of signaling the wakeup event as appropriate, it will be lost. However, if the driver does take care of that, the extra pm_wakeup_event() call in the core is redundant. Accordingly, drop the conditional pm_wakeup_event() call fron __device_suspend() and make the latter call pm_runtime_barrier() alone. Also modify the comment next to that call to reflect the new code and extend it to mention the need to avoid unwanted interactions between runtime PM and system-wide device suspend callbacks. Fixes: 1e2ef05bb8cf8 ("PM: Limit race conditions between runtime PM and system sleep (v2)") Signed-off-by: Rafael J. Wysocki Acked-by: Alan Stern Reported-by: Utkarsh H Patel Tested-by: Utkarsh H Patel Tested-by: Pengfei Xu Cc: All applicable Signed-off-by: Greg Kroah-Hartman

PM: core: Fix handling of devices deleted during system-wide resume

2020-02-14T21:32:13Z

commit 0552e05fdfea191a2cf3a0abd33574b5ef9ca818 upstream. If a device is deleted by one of its system-wide resume callbacks (for example, because it does not appear to be present or accessible any more) along with its children, the resume of the children may continue leading to use-after-free errors and other issues (potentially). Namely, if the device's children are resumed asynchronously, their resume may have been scheduled already before the device's callback runs and so the device may be deleted while dpm_wait_for_superior() is being executed for them. The memory taken up by the parent device object may be freed then while dpm_wait() is waiting for the parent's resume callback to complete, which leads to a use-after-free. Moreover, the resume of the children is really not expected to continue after they have been unregistered, so it must be terminated right away in that case. To address this problem, modify dpm_wait_for_superior() to check if the target device is still there in the system-wide PM list of devices and if so, to increment its parent's reference counter, both under dpm_list_mtx which prevents device_del() running for the child from dropping the parent's reference counter prematurely. If the device is not present in the system-wide PM list of devices any more, the resume of it cannot continue, so check that again after dpm_wait() returns, which means that the parent's callback has been completed, and pass the result of that check to the caller of dpm_wait_for_superior() to allow it to abort the device's resume if it is not there any more. Link: https://lore.kernel.org/linux-pm/1579568452-27253-1-git-send-email-chanho.min@lge.com Reported-by: Chanho Min Cc: All applicable Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

PM: sleep: Fix possible overflow in pm_system_cancel_wakeup()

2020-01-27T13:46:40Z

[ Upstream commit 2933954b71f10d392764f95eec0f0aa2d103054b ] It is not actually guaranteed that pm_abort_suspend will be nonzero when pm_system_cancel_wakeup() is called which may lead to subtle issues, so make it use atomic_dec_if_positive() instead of atomic_dec() for the safety sake. Fixes: 33e4f80ee69b ("ACPI / PM: Ignore spurious SCI wakeups from suspend-to-idle") Signed-off-by: Rafael J. Wysocki Acked-by: Thomas Gleixner Signed-off-by: Sasha Levin

PM / Domains: Deal with multiple states but no governor in genpd

2019-12-01T08:13:38Z

[ Upstream commit 2c9b7f8772033cc8bafbd4eefe2ca605bf3eb094 ] A caller of pm_genpd_init() that provides some states for the genpd via the ->states pointer in the struct generic_pm_domain, should also provide a governor. This because it's the job of the governor to pick a state that satisfies the constraints. Therefore, let's print a warning to inform the user about such bogus configuration and avoid to bail out, by instead picking the shallowest state before genpd invokes the ->power_off() callback. Signed-off-by: Ulf Hansson Reviewed-by: Lina Iyer Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

Revert "OPP: Protect dev_list with opp_table lock"

2019-11-24T07:22:45Z

This reverts commit 714ab224a8db6e8255c61a42613de9349ceb0bba which is commit 3d2556992a878a2210d3be498416aee39e0c32aa upstream. Turns out to break the build on the odroid machines, so it needs to be reverted. Reported-by: Viresh Kumar Reported-by: "kernelci.org bot" Cc: Niklas Cassel Cc: Sasha Levin Signed-off-by: Greg Kroah-Hartman

OPP: Protect dev_list with opp_table lock

2019-11-20T17:00:13Z

[ Upstream commit 3d2556992a878a2210d3be498416aee39e0c32aa ] The dev_list needs to be protected with a lock, else we may have simultaneous access (addition/removal) to it and that would be racy. Extend scope of the opp_table lock to protect dev_list as well. Tested-by: Niklas Cassel Signed-off-by: Viresh Kumar Signed-off-by: Sasha Levin

PM / core: Propagate dev->power.wakeup_path when no callbacks

2019-05-31T13:47:28Z

[ Upstream commit dc351d4c5f4fe4d0f274d6d660227be0c3a03317 ] The dev->power.direct_complete flag may become set in device_prepare() in case the device don't have any PM callbacks (dev->power.no_pm_callbacks is set). This leads to a broken behaviour, when there is child having wakeup enabled and relies on its parent to be used in the wakeup path. More precisely, when the direct complete path becomes selected for the child in __device_suspend(), the propagation of the dev->power.wakeup_path becomes skipped as well. Let's address this problem, by checking if the device is a part the wakeup path or has wakeup enabled, then prevent the direct complete path from being used. Reported-by: Loic Pallardy Signed-off-by: Ulf Hansson [ rjw: Comment cleanup ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

PM / wakeup: Rework wakeup source timer cancellation

2019-03-23T13:35:29Z

commit 1fad17fb1bbcd73159c2b992668a6957ecc5af8a upstream. If wakeup_source_add() is called right after wakeup_source_remove() for the same wakeup source, timer_setup() may be called for a potentially scheduled timer which is incorrect. To avoid that, move the wakeup source timer cancellation from wakeup_source_drop() to wakeup_source_remove(). Moreover, make wakeup_source_remove() clear the timer function after canceling the timer to let wakeup_source_not_registered() treat unregistered wakeup sources in the same way as the ones that have never been registered. Signed-off-by: Viresh Kumar Cc: 4.4+ # 4.4+ [ rjw: Subject, changelog, merged two patches together ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman