Re: [PATCH 3/3] ALSA: compress: fix partial_drain completion state

[Srinivas Kandagatla <srinivas.kandagatla@linaro.org>]

On 19/06/2020 05:54, 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)")
> Reported-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> Signed-off-by: Vinod Koul <vkoul@kernel.org>
> ---

Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>


>   include/sound/compress_driver.h | 12 +++++++++++-
>   sound/core/compress_offload.c   |  4 ++++
>   2 files changed, 15 insertions(+), 1 deletion(-)
> 
> 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");
>