[v3,3/3] ALSA: compress: fix partial_drain completion state
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Message ID 20200625154651.99758-4-vkoul@kernel.org
State New
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Series
  • ALSA: compress: Document stream states and fix gapless SM
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Commit Message

Vinod Koul June 25, 2020, 3:46 p.m. UTC
On partial_drain completion we should be in SNDRV_PCM_STATE_RUNNING
state, so set that for partially draining streams in
snd_compr_drain_notify() and use a flag for partially draining streams

While at it, add locks for stream state change in
snd_compr_drain_notify() as well.

Fixes: f44f2a5417b2 ("ALSA: compress: fix drain calls blocking other compress functions (v6)")
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
 include/sound/compress_driver.h | 12 +++++++++++-
 sound/core/compress_offload.c   |  4 ++++
 2 files changed, 15 insertions(+), 1 deletion(-)

Comments

Charles Keepax June 26, 2020, 10:35 a.m. UTC | #1
On Thu, Jun 25, 2020 at 09:16:51PM +0530, Vinod Koul wrote:
> On partial_drain completion we should be in SNDRV_PCM_STATE_RUNNING
> state, so set that for partially draining streams in
> snd_compr_drain_notify() and use a flag for partially draining streams
> 
> While at it, add locks for stream state change in
> snd_compr_drain_notify() as well.
> 
> Fixes: f44f2a5417b2 ("ALSA: compress: fix drain calls blocking other compress functions (v6)")
> Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> Signed-off-by: Vinod Koul <vkoul@kernel.org>
> ---
> @@ -187,7 +189,15 @@ static inline void snd_compr_drain_notify(struct snd_compr_stream *stream)
>  	if (snd_BUG_ON(!stream))
>  		return;
>  
> -	stream->runtime->state = SNDRV_PCM_STATE_SETUP;
> +	mutex_lock(&stream->device->lock);
> +	/* for partial_drain case we are back to running state on success */
> +	if (stream->partial_drain) {
> +		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
> +		stream->partial_drain = false; /* clear this flag as well */
> +	} else {
> +		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
> +	}
> +	mutex_unlock(&stream->device->lock);

You have added locking here in snd_compr_drain_notify but....
>  
>  	wake_up(&stream->runtime->sleep);
>  }
> diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
> index e618580feac4..1c4b2cf450a0 100644
> --- a/sound/core/compress_offload.c
> +++ b/sound/core/compress_offload.c
> @@ -803,6 +803,9 @@ static int snd_compr_stop(struct snd_compr_stream *stream)
>  
>  	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
>  	if (!retval) {
> +		/* clear flags and stop any drain wait */
> +		stream->partial_drain = false;
> +		stream->metadata_set = false;
>  		snd_compr_drain_notify(stream);

that can be called from snd_compr_stop here which is already
holding the lock resulting in deadlock.

Thanks,
Charles
Vinod Koul June 29, 2020, 5:16 a.m. UTC | #2
On 26-06-20, 10:35, Charles Keepax wrote:

> > -	stream->runtime->state = SNDRV_PCM_STATE_SETUP;
> > +	mutex_lock(&stream->device->lock);
> > +	/* for partial_drain case we are back to running state on success */
> > +	if (stream->partial_drain) {
> > +		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
> > +		stream->partial_drain = false; /* clear this flag as well */
> > +	} else {
> > +		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
> > +	}
> > +	mutex_unlock(&stream->device->lock);
> 
> You have added locking here in snd_compr_drain_notify but....
> >  
> >  	wake_up(&stream->runtime->sleep);
> >  }
> > diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
> > index e618580feac4..1c4b2cf450a0 100644
> > --- a/sound/core/compress_offload.c
> > +++ b/sound/core/compress_offload.c
> > @@ -803,6 +803,9 @@ static int snd_compr_stop(struct snd_compr_stream *stream)
> >  
> >  	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
> >  	if (!retval) {
> > +		/* clear flags and stop any drain wait */
> > +		stream->partial_drain = false;
> > +		stream->metadata_set = false;
> >  		snd_compr_drain_notify(stream);
> 
> that can be called from snd_compr_stop here which is already
> holding the lock resulting in deadlock.

Thanks Charles, right somehow my testing missed this, have verified that
it is the case.

I will remove the locks here, and we should add a comment to note this..

Thanks

Patch
diff mbox series

diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h
index 3df8d8c90191..93a5897201ea 100644
--- a/include/sound/compress_driver.h
+++ b/include/sound/compress_driver.h
@@ -66,6 +66,7 @@  struct snd_compr_runtime {
  * @direction: stream direction, playback/recording
  * @metadata_set: metadata set flag, true when set
  * @next_track: has userspace signal next track transition, true when set
+ * @partial_drain: undergoing partial_drain for stream, true when set
  * @private_data: pointer to DSP private data
  * @dma_buffer: allocated buffer if any
  */
@@ -78,6 +79,7 @@  struct snd_compr_stream {
 	enum snd_compr_direction direction;
 	bool metadata_set;
 	bool next_track;
+	bool partial_drain;
 	void *private_data;
 	struct snd_dma_buffer dma_buffer;
 };
@@ -187,7 +189,15 @@  static inline void snd_compr_drain_notify(struct snd_compr_stream *stream)
 	if (snd_BUG_ON(!stream))
 		return;
 
-	stream->runtime->state = SNDRV_PCM_STATE_SETUP;
+	mutex_lock(&stream->device->lock);
+	/* for partial_drain case we are back to running state on success */
+	if (stream->partial_drain) {
+		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
+		stream->partial_drain = false; /* clear this flag as well */
+	} else {
+		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
+	}
+	mutex_unlock(&stream->device->lock);
 
 	wake_up(&stream->runtime->sleep);
 }
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index e618580feac4..1c4b2cf450a0 100644
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -803,6 +803,9 @@  static int snd_compr_stop(struct snd_compr_stream *stream)
 
 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
 	if (!retval) {
+		/* clear flags and stop any drain wait */
+		stream->partial_drain = false;
+		stream->metadata_set = false;
 		snd_compr_drain_notify(stream);
 		stream->runtime->total_bytes_available = 0;
 		stream->runtime->total_bytes_transferred = 0;
@@ -960,6 +963,7 @@  static int snd_compr_partial_drain(struct snd_compr_stream *stream)
 	if (stream->next_track == false)
 		return -EPERM;
 
+	stream->partial_drain = true;
 	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_PARTIAL_DRAIN);
 	if (retval) {
 		pr_debug("Partial drain returned failure\n");