kernel/linux.git/drivers/base/power, branch v5.9.2

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

2020-08-25T14:28:23+00:00

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

PM: runtime: Improve kerneldoc of pm_runtime_get_if_active()

2020-08-04T10:40:10+00:00

The kerneldoc comment of pm_runtime_get_if_active() doesn't list the second argument of the function properly, so fix that and while at it clarify that comment somewhat and add some markup to it. Signed-off-by: Rafael J. Wysocki Reviewed-by: Sakari Ailus

Merge branches 'pm-sleep', 'pm-domains', 'powercap' and 'pm-tools'

2020-08-03T11:12:44+00:00

* pm-sleep: PM: sleep: spread "const char *" correctness PM: hibernate: fix white space in a few places freezer: Add unsafe version of freezable_schedule_timeout_interruptible() for NFS PM: sleep: core: Emit changed uevent on wakeup_sysfs_add/remove * pm-domains: PM: domains: Restore comment indentation for generic_pm_domain.child_links PM: domains: Fix up terminology with parent/child * powercap: powercap: Add Power Limit4 support powercap: idle_inject: Replace play_idle() with play_idle_precise() in comments powercap: intel_rapl: add support for Sapphire Rapids * pm-tools: pm-graph v5.7 - important s2idle fixes cpupower: Replace HTTP links with HTTPS ones cpupower: Fix NULL but dereferenced coccicheck errors cpupower: Fix comparing pointer to 0 coccicheck warns

PM: sleep: core: Emit changed uevent on wakeup_sysfs_add/remove

2020-07-14T17:19:04+00:00

Udev rules that depend on the power/wakeup attribute don't get triggered correctly if device_set_wakeup_capable is called after the device is created. This can happen for several reasons (driver sets wakeup after device is created, wakeup is changed on parent device, etc) and it seems reasonable to emit a changed event when adding or removing attributes on the device. Signed-off-by: Abhishek Pandit-Subedi Reviewed-by: Greg Kroah-Hartman Reviewed-by: Stephen Boyd Signed-off-by: Rafael J. Wysocki

PM: domains: Fix up terminology with parent/child

2020-07-09T12:24:00+00:00

The genpd infrastructure uses the terms master/slave, but such uses have no external exposures (not even in Documentation/driver-api/pm/*) and are not mandated by nor associated with any external specifications. Change the language used through-out to parent/child. There was one possible exception in the debugfs node "pm_genpd/pm_genpd_summary" but its path has no hits outside of the kernel itself when performing a code search[1], and it seems even this single usage has been non-functional since it was introduced due to a typo in the Python ("apend" instead of correct "append"). Fix the typo while we're at it. Link: https://codesearch.debian.net/ # [1] Signed-off-by: Kees Cook Reviewed-by: Greg Kroah-Hartman Reviewed-by: Kieran Bingham Signed-off-by: Rafael J. Wysocki

PM: sleep: core: mark 2 functions as __init to save some memory

2020-06-23T15:35:33+00:00

'early_resume_init()' and 'late_resume_init() 'are only called respectively via 'early_resume_init' and 'late_resume_init'. They can be marked as __init to save a few bytes of memory. Signed-off-by: Christophe JAILLET [ rjw: Subject edits ] Signed-off-by: Rafael J. Wysocki

kernel: rename show_stack_loglvl() => show_stack()

2020-06-09T16:39:13+00:00

Now the last users of show_stack() got converted to use an explicit log level, show_stack_loglvl() can drop it's redundant suffix and become once again well known show_stack(). Signed-off-by: Dmitry Safonov Signed-off-by: Andrew Morton Link: http://lkml.kernel.org/r/20200418201944.482088-51-dima@arista.com Signed-off-by: Linus Torvalds

power: use show_stack_loglvl()

2020-06-09T16:39:12+00:00

Aligning with other watchdog messages just before panic - use KERN_EMERG. Signed-off-by: Dmitry Safonov Signed-off-by: Andrew Morton Acked-by: Rafael J. Wysocki Cc: Greg Kroah-Hartman Cc: Len Brown Cc: Pavel Machek Link: http://lkml.kernel.org/r/20200418201944.482088-47-dima@arista.com Signed-off-by: Linus Torvalds

Merge branches 'pm-core' and 'pm-sleep'

2020-06-01T13:19:08+00:00

* pm-core: PM: runtime: Replace pm_runtime_callbacks_present() PM: runtime: clk: Fix clk_pm_runtime_get() error path PM: runtime: Make clear what we do when conditions are wrong in rpm_suspend() * pm-sleep: PM: hibernate: Restrict writes to the resume device PM: hibernate: Split off snapshot dev option PM: hibernate: Incorporate concurrency handling PM: sleep: Helpful edits for devices.rst documentation Documentation: PM: sleep: Update driver flags documentation PM: sleep: core: Rename DPM_FLAG_LEAVE_SUSPENDED PM: sleep: core: Rename DPM_FLAG_NEVER_SKIP PM: sleep: core: Rename dev_pm_smart_suspend_and_suspended() PM: sleep: core: Rename dev_pm_may_skip_resume() PM: sleep: core: Rework the power.may_skip_resume handling PM: sleep: core: Do not skip callbacks in the resume phase PM: sleep: core: Fold functions into their callers PM: sleep: core: Simplify the SMART_SUSPEND flag handling

PM: runtime: Replace pm_runtime_callbacks_present()

2020-05-29T16:03:12+00:00

The name of pm_runtime_callbacks_present() is confusing, because it suggests that the device has PM-runtime callbacks if 'true' is returned by that function, but in fact that may not be the case, so replace it with pm_runtime_has_no_callbacks() which is not ambiguous. No functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson