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 <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Utkarsh H Patel <utkarsh.h.patel@intel.com>
Tested-by: Utkarsh H Patel <utkarsh.h.patel@intel.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
'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 <christophe.jaillet@wanadoo.fr> [ rjw: Subject edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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 <dima@arista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200418201944.482088-51-dima@arista.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Aligning with other watchdog messages just before panic - use KERN_EMERG. Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Link: http://lkml.kernel.org/r/20200418201944.482088-47-dima@arista.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 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
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 <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
rpm_suspend() simple bails out when conditions are wrong. But this is not immediately obvious from the code. Make it clear what we do when conditions are wrong in rpm_suspend(). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Rename DPM_FLAG_LEAVE_SUSPENDED to DPM_FLAG_MAY_SKIP_RESUME which matches its purpose more closely. No functional impact. Suggested-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Wolfram Sang <wsa@the-dreams.de> # for I2C Acked-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Rename DPM_FLAG_NEVER_SKIP to DPM_FLAG_NO_DIRECT_COMPLETE which matches its purpose more closely. No functional impact. Suggested-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> # for PCI parts Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Alex Deucher <alexander.deucher@amd.com>