ALSA: hda/hdmi: fix race in handling acomp ELD notification at resume
authorKai Vehmanen <kai.vehmanen@linux.intel.com>
Fri, 16 Apr 2021 13:11:57 +0000 (16:11 +0300)
committerTakashi Iwai <tiwai@suse.de>
Fri, 16 Apr 2021 14:01:21 +0000 (16:01 +0200)
commit0c37e2eb6b83e375e8a654d01598292d5591fc65
treece0561adb1eb0edcfa68f822db8bab25f2a8c38a
parent75b62ab65d2715ce6ff0794033d61ab9dc4a2dfc
ALSA: hda/hdmi: fix race in handling acomp ELD notification at resume

When snd-hda-codec-hdmi is used with ASoC HDA controller like SOF (acomp
used for ELD notifications), display connection change done during suspend,
can be lost due to following sequence of events:

  1. system in S3 suspend
  2. DP/HDMI receiver connected
  3. system resumed
  4. HDA controller resumed, but card->deferred_resume_work not complete
  5. acomp eld_notify callback
  6. eld_notify ignored as power state is not CTL_POWER_D0
  7. HDA resume deferred work completed, power state set to CTL_POWER_D0

This results in losing the notification, and the jack state reported to
user-space is not correct.

The check on step 6 was added in commit 8ae743e82f0b ("ALSA: hda - Skip
ELD notification during system suspend"). It would seem with the deferred
resume logic in ASoC core, this check is not safe.

Fix the issue by modifying the check to use "dev.power.power_state.event"
instead of ALSA specific card power state variable.

BugLink: https://github.com/thesofproject/linux/issues/2825
Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20210416131157.1881366-1-kai.vehmanen@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
sound/pci/hda/patch_hdmi.c