diff options
| author | Dylan Reid <dgreid@chromium.org> | 2012-09-28 15:57:01 -0700 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2012-10-06 16:49:30 +0200 |
| commit | d17344b3547669f5b6ee4fda993d03737a141bd6 (patch) | |
| tree | 2f73c0f42b3b8489d6771f070ec9c801b6e2cc5e | |
| 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>
| -rw-r--r-- | sound/pci/hda/hda_codec.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c index 960800b862ab..c0ab72cbeed1 100644 --- a/sound/pci/hda/hda_codec.c +++ b/sound/pci/hda/hda_codec.c @@ -3612,7 +3612,7 @@ static inline void hda_exec_init_verbs(struct hda_codec *codec) {} * call suspend and power-down; used both from PM and power-save * this function returns the power state in the end */ -static unsigned int hda_call_codec_suspend(struct hda_codec *codec) +static unsigned int hda_call_codec_suspend(struct hda_codec *codec, bool in_wq) { unsigned int state; @@ -3620,7 +3620,9 @@ static unsigned int hda_call_codec_suspend(struct hda_codec *codec) codec->patch_ops.suspend(codec); hda_cleanup_all_streams(codec); state = hda_set_power_state(codec, AC_PWRST_D3); - cancel_delayed_work(&codec->power_work); + /* Cancel delayed work if we aren't currently running from it. */ + if (!in_wq) + cancel_delayed_work_sync(&codec->power_work); spin_lock(&codec->power_lock); snd_hda_update_power_acct(codec); trace_hda_power_down(codec); @@ -4478,7 +4480,7 @@ static void hda_power_work(struct work_struct *work) } spin_unlock(&codec->power_lock); - state = hda_call_codec_suspend(codec); + state = hda_call_codec_suspend(codec, true); codec->pm_down_notified = 0; if (!bus->power_keep_link_on && (state & AC_PWRST_CLK_STOP_OK)) { codec->pm_down_notified = 1; @@ -5127,7 +5129,7 @@ int snd_hda_suspend(struct hda_bus *bus) list_for_each_entry(codec, &bus->codec_list, list) { if (hda_codec_is_power_on(codec)) - hda_call_codec_suspend(codec); + hda_call_codec_suspend(codec, false); } return 0; } |