[alsa-devel] [PATCH] ALSA: pcm_dmaengine: Add check during device suspend

[Takashi Iwai]

At Mon, 19 May 2014 14:53:53 +0530,
Tushar Behera wrote:
> 
> Currently snd_dmaengine_pcm_trigger() calls dmaengine_pause()
> unconditinally during device suspend. In case where DMA controller
> doesn't support PAUSE/RESUME functionality, this call is not able
> to stop the DMA controller. In this scenario, audio playback doesn't
> resume after device resume.
> 
> Calling dmaengine_pause/dmaengine_terminate_all conditionally fixes
> the issue.
> 
> It has been tested with audio playback on Samsung platform having
> PL330 DMA controller which doesn't support PAUSE/RESUME.
> 
> Signed-off-by: Tushar Behera <tushar.behera at linaro.org>

Thanks, applied with Ack from Las.  Found in for-linus branch of sound
git tree.


Takashi

> ---
>  sound/core/pcm_dmaengine.c |    6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c
> index 94d0873..76cbb9e 100644
> --- a/sound/core/pcm_dmaengine.c
> +++ b/sound/core/pcm_dmaengine.c
> @@ -182,6 +182,7 @@ static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
>  int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
>  {
>  	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
> +	struct snd_pcm_runtime *runtime = substream->runtime;
>  	int ret;
>  
>  	switch (cmd) {
> @@ -196,6 +197,11 @@ int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
>  		dmaengine_resume(prtd->dma_chan);
>  		break;
>  	case SNDRV_PCM_TRIGGER_SUSPEND:
> +		if (runtime->info & SNDRV_PCM_INFO_PAUSE)
> +			dmaengine_pause(prtd->dma_chan);
> +		else
> +			dmaengine_terminate_all(prtd->dma_chan);
> +		break;
>  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
>  		dmaengine_pause(prtd->dma_chan);
>  		break;
> -- 
> 1.7.9.5
>