ASoC: Prevent pop_wait overwrite
pop_wait is used to determine if a deferred playback close
needs to be cancelled when the a PCM is open or if after
the power-down delay expires it needs to run. pop_wait is
associated with the CODEC DAI, so the CODEC DAI must be
unique. This holds true for most CODECs, except for the
dummy CODEC and its DAI.
In DAI links with non-unique dummy CODECs (e.g. front-ends),
pop_wait can be overwritten by another DAI link using also a
dummy CODEC. Failure to cancel a deferred close can cause
mute due to the DAPM STOP event sent in the deferred work.
One scenario where pop_wait is overwritten and causing mute
is below (where hw:0,0 and hw:0,1 are two front-ends with
default pmdown_time = 5 secs):
aplay /dev/urandom -D hw:0,0 -c 2 -r 48000 -f S16_LE -d 1
sleep 1
aplay /dev/urandom -D hw:0,1 -c 2 -r 48000 -f S16_LE -d 3 &
aplay /dev/urandom -D hw:0,0 -c 2 -r 48000 -f S16_LE
Since CODECs may not be unique, pop_wait is moved to the PCM
runtime structure. Creating separate dummy CODECs for each
DAI link can also solve the problem, but at this point it's
only pop_wait variable in the CODEC DAI that has negative
effects by not being unique.
Signed-off-by: Misael Lopez Cruz <misael.lopez@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index ef22d0b..3a2423b 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -333,11 +333,11 @@
pr_debug("pop wq checking: %s status: %s waiting: %s\n",
codec_dai->driver->playback.stream_name,
codec_dai->playback_active ? "active" : "inactive",
- codec_dai->pop_wait ? "yes" : "no");
+ rtd->pop_wait ? "yes" : "no");
/* are we waiting on this codec DAI stream */
- if (codec_dai->pop_wait == 1) {
- codec_dai->pop_wait = 0;
+ if (rtd->pop_wait == 1) {
+ rtd->pop_wait = 0;
snd_soc_dapm_stream_event(rtd, SNDRV_PCM_STREAM_PLAYBACK,
SND_SOC_DAPM_STREAM_STOP);
}
@@ -407,7 +407,7 @@
SND_SOC_DAPM_STREAM_STOP);
} else {
/* start delayed pop wq here for playback streams */
- codec_dai->pop_wait = 1;
+ rtd->pop_wait = 1;
schedule_delayed_work(&rtd->delayed_work,
msecs_to_jiffies(rtd->pmdown_time));
}
@@ -478,8 +478,8 @@
/* cancel any delayed stream shutdown that is pending */
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
- codec_dai->pop_wait) {
- codec_dai->pop_wait = 0;
+ rtd->pop_wait) {
+ rtd->pop_wait = 0;
cancel_delayed_work(&rtd->delayed_work);
}