This is a note to let you know that I've just added the patch titled
ASoC: soc-pcm: serialize BE triggers
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
asoc-soc-pcm-serialize-be-triggers.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a35e54d4c8d72fa5da81e4350ad4eca1ed349cd6
Author: Takashi Iwai <tiwai@xxxxxxx>
Date: Tue Dec 7 11:37:43 2021 -0600
ASoC: soc-pcm: serialize BE triggers
[ Upstream commit b2ae80663008a7662febe7d13f14ea1b2eb0cd51 ]
When more than one FE is connected to a BE, e.g. in a mixing use case,
the BE can be triggered multiple times when the FE are opened/started
concurrently. This race condition is problematic in the case of
SoundWire BE dailinks, and this is not desirable in a general
case.
This patch relies on the existing BE PCM lock, which takes atomicity into
account. The locking model assumes that all interactions start with
the FE, so that there is no deadlock between FE and BE locks.
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
[test, checkpatch fix and clarification of commit message by plbossart]
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Reviewed-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
Reviewed-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20211207173745.15850-5-pierre-louis.bossart@xxxxxxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index d26a1f12c513a..7c7ae69f9410d 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -46,12 +46,18 @@ static inline void snd_soc_dpcm_stream_lock_irq(struct snd_soc_pcm_runtime *rtd,
snd_pcm_stream_lock_irq(snd_soc_dpcm_get_substream(rtd, stream));
}
+#define snd_soc_dpcm_stream_lock_irqsave(rtd, stream, flags) \
+ snd_pcm_stream_lock_irqsave(snd_soc_dpcm_get_substream(rtd, stream), flags)
+
static inline void snd_soc_dpcm_stream_unlock_irq(struct snd_soc_pcm_runtime *rtd,
int stream)
{
snd_pcm_stream_unlock_irq(snd_soc_dpcm_get_substream(rtd, stream));
}
+#define snd_soc_dpcm_stream_unlock_irqrestore(rtd, stream, flags) \
+ snd_pcm_stream_unlock_irqrestore(snd_soc_dpcm_get_substream(rtd, stream), flags)
+
#define DPCM_MAX_BE_USERS 8
static inline const char *soc_cpu_dai_name(struct snd_soc_pcm_runtime *rtd)
@@ -2094,6 +2100,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
{
struct snd_soc_pcm_runtime *be;
struct snd_soc_dpcm *dpcm;
+ unsigned long flags;
int ret = 0;
for_each_dpcm_be(fe, stream, dpcm) {
@@ -2102,9 +2109,11 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
be = dpcm->be;
be_substream = snd_soc_dpcm_get_substream(be, stream);
+ snd_soc_dpcm_stream_lock_irqsave(be, stream, flags);
+
/* is this op for this BE ? */
if (!snd_soc_dpcm_be_can_update(fe, be, stream))
- continue;
+ goto next;
dev_dbg(be->dev, "ASoC: trigger BE %s cmd %d\n",
be->dai_link->name, cmd);
@@ -2114,77 +2123,80 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_PREPARE) &&
(be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP) &&
(be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED))
- continue;
+ goto next;
ret = soc_pcm_trigger(be_substream, cmd);
if (ret)
- goto end;
+ goto next;
be->dpcm[stream].state = SND_SOC_DPCM_STATE_START;
break;
case SNDRV_PCM_TRIGGER_RESUME:
if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_SUSPEND))
- continue;
+ goto next;
ret = soc_pcm_trigger(be_substream, cmd);
if (ret)
- goto end;
+ goto next;
be->dpcm[stream].state = SND_SOC_DPCM_STATE_START;
break;
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED))
- continue;
+ goto next;
ret = soc_pcm_trigger(be_substream, cmd);
if (ret)
- goto end;
+ goto next;
be->dpcm[stream].state = SND_SOC_DPCM_STATE_START;
break;
case SNDRV_PCM_TRIGGER_STOP:
if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_START) &&
(be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED))
- continue;
+ goto next;
if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
- continue;
+ goto next;
ret = soc_pcm_trigger(be_substream, cmd);
if (ret)
- goto end;
+ goto next;
be->dpcm[stream].state = SND_SOC_DPCM_STATE_STOP;
break;
case SNDRV_PCM_TRIGGER_SUSPEND:
if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START)
- continue;
+ goto next;
if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
- continue;
+ goto next;
ret = soc_pcm_trigger(be_substream, cmd);
if (ret)
- goto end;
+ goto next;
be->dpcm[stream].state = SND_SOC_DPCM_STATE_SUSPEND;
break;
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START)
- continue;
+ goto next;
if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
- continue;
+ goto next;
ret = soc_pcm_trigger(be_substream, cmd);
if (ret)
- goto end;
+ goto next;
be->dpcm[stream].state = SND_SOC_DPCM_STATE_PAUSED;
break;
}
+next:
+ snd_soc_dpcm_stream_unlock_irqrestore(be, stream, flags);
+ if (ret)
+ break;
}
-end:
if (ret < 0)
dev_err(fe->dev, "ASoC: %s() failed at %s (%d)\n",
__func__, be->dai_link->name, ret);
