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authorDylan Reid <dgreid@chromium.org>2012-09-28 15:57:01 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-10-13 05:50:33 +0900
commit22e22876160b6b19e4aa52d8e562149840945e9b (patch)
treed28ca9af95676140633f191ea2fe8674c2cdb206 /sound
parent93bfa6e4dade09e6b92a84990f479c3d59a69e14 (diff)
ALSA: hda - Fix hang caused by race during suspend.
commit d17344b3547669f5b6ee4fda993d03737a141bd6 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
-rw-r--r--sound/pci/hda/hda_codec.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 1c65cc5e3a31..38fdefc9b0ee 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -3580,7 +3580,7 @@ static inline void hda_exec_init_verbs(struct hda_codec *codec) {}
/*
* call suspend and power-down; used both from PM and power-save
*/
-static void hda_call_codec_suspend(struct hda_codec *codec)
+static void hda_call_codec_suspend(struct hda_codec *codec, bool in_wq)
{
if (codec->patch_ops.suspend)
codec->patch_ops.suspend(codec);
@@ -3589,7 +3589,9 @@ static void hda_call_codec_suspend(struct hda_codec *codec)
codec->afg ? codec->afg : codec->mfg,
AC_PWRST_D3);
#ifdef CONFIG_SND_HDA_POWER_SAVE
- 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);
@@ -4410,7 +4412,7 @@ static void hda_power_work(struct work_struct *work)
}
spin_unlock(&codec->power_lock);
- hda_call_codec_suspend(codec);
+ hda_call_codec_suspend(codec, true);
if (bus->ops.pm_notify)
bus->ops.pm_notify(bus);
}
@@ -5076,7 +5078,7 @@ 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;
}