Re: [PATCH] ALSA: pcm_dmaengine: Add check during device suspend

[Lars-Peter Clausen]

On 05/19/2014 11:23 AM, 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@xxxxxxxxxx>

Acked-by: Lars-Peter Clausen <lars@xxxxxxxxxx>

Thanks.

> ---
>   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;

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