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author | Dylan Reid <dgreid@chromium.org> | 2012-09-28 15:57:01 -0700 |
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committer | Takashi Iwai <tiwai@suse.de> | 2012-10-06 16:49:30 +0200 |
commit | d17344b3547669f5b6ee4fda993d03737a141bd6 (patch) | |
tree | 2f73c0f42b3b8489d6771f070ec9c801b6e2cc5e /mm | |
parent | 395d9dd5dd13c6aa3c8c61a31126af98cd1e747d (diff) | |
download | linux-d17344b3547669f5b6ee4fda993d03737a141bd6.tar.bz2 |
ALSA: hda - Fix hang caused by race during suspend.
There was a race condition when the system suspends while hda_power_work
is running in the work queue. If system suspend (snd_hda_suspend)
happens after the work queue releases power_lock but before it calls
hda_call_codec_suspend, codec_suspend runs with power_on=0, causing the
codec to power up for register reads, and hanging when it calls
cancel_delayed_work_sync from the running work queue.
The call chain from the work queue will look like this:
hda_power_work <<- power_on = 1, unlock, then power_on cleard by suspend
hda_call_codec_suspend
hda_set_power_state
snd_hda_codec_read
codec_exec_verb
snd_hda_power_up
snd_hda_power_save
__snd_hda_power_up
cancel_delayed_work_sync <<-- cancelling executing wq
Fix this by waiting for the work queue to finish before starting suspend
if suspend is not happening on the work queue.
Signed-off-by: Dylan Reid <dgreid@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'mm')
0 files changed, 0 insertions, 0 deletions