At Tue, 27 Aug 2013 12:10:32 +0530,
Vinod Koul wrote:
>
> Since we dont have lock over the function, we need to aquire mutex when checking
> and modfying states in drain and partial_drain handlers
>
> Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>
> ---
> sound/core/compress_offload.c | 22 +++++++++++++++++++---
> 1 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
> index 868aefd..e640f8c 100644
> --- a/sound/core/compress_offload.c
> +++ b/sound/core/compress_offload.c
> @@ -676,18 +676,29 @@ static int snd_compr_stop(struct snd_compr_stream *stream)
> return retval;
> }
>
> +/* this fn is called without lock being held and we change stream states here
> + * so while using the stream state auquire the lock but relase before invoking
> + * DSP as the call will possibly take a while
> + */
> static int snd_compr_drain(struct snd_compr_stream *stream)
> {
> int retval;
>
> + mutex_lock(&stream->device->lock);
> if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
> - stream->runtime->state == SNDRV_PCM_STATE_SETUP)
> - return -EPERM;
> + stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
> + retval = -EPERM;
> + goto ret;
> + }
> + mutex_unlock(&stream->device->lock);
> retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN);
Why release the lock here? The trigger callback is called within this
mutex lock in other places.
Takashi
> + mutex_lock(&stream->device->lock);
> if (!retval) {
> stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
> wake_up(&stream->runtime->sleep);
> }
> +ret:
> + mutex_unlock(&stream->device->lock);
> return retval;
> }
>
> @@ -716,9 +727,14 @@ static int snd_compr_next_track(struct snd_compr_stream *stream)
> static int snd_compr_partial_drain(struct snd_compr_stream *stream)
> {
> int retval;
> +
> + mutex_lock(&stream->device->lock);
> if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
> - stream->runtime->state == SNDRV_PCM_STATE_SETUP)
> + stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
> + mutex_unlock(&stream->device->lock);
> return -EPERM;
> + }
> + mutex_unlock(&stream->device->lock);
> /* stream can be drained only when next track has been signalled */
> if (stream->next_track == false)
> return -EPERM;
> --
> 1.7.0.4
>
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