1. 08 Sep, 2010 1 commit
    • Colin Cross's avatar
      PM: Prevent waiting forever on asynchronous resume after failing suspend · 152e1d59
      Colin Cross authored
      During suspend, the power.completion is expected to be set when a
      device has not yet started suspending.  Set it on init to fix a
      corner case where a device is resumed when its parent has never
      suspended.
      
      Consider three drivers, A, B, and C.  The parent of A is C, and C
      has async_suspend set.  On boot, C->power.completion is initialized
      to 0.
      
      During the first suspend:
      suspend_devices_and_enter(...)
       dpm_resume(...)
        device_suspend(A)
        device_suspend(B) returns error, aborts suspend
       dpm_resume_end(...)
         dpm_resume(...)
          device_resume(A)
           dpm_wait(A->parent == C)
            wait_for_completion(C->power.completion)
      
      The wait_for_completion will never complete, because
      complete_all(C->power.completion) will only be called from
      device_suspend(C) or device_resume(C), neither of which is called
      if suspend is aborted before C.
      
      After a successful suspend->resume cycle, where B doesn't abort
      suspend, C->power.completion is left in the completed state by the
      call to device_resume(C), and the same call path will work if B
      aborts suspend.
      Signed-off-by: default avatarColin Cross <ccross@android.com>
      Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
      152e1d59
  2. 07 Sep, 2010 39 commits