[alsa-devel] [PATCH v3 1/3] ASoC: davinci-mcasp: Constraint on the period and buffer size based on FIFO usage

[Peter Ujfalusi]

On 03/18/2014 03:20 PM, Peter Ujfalusi wrote:
> We need to place constraint on the period if the read or write AFIFO
> is enabled and it is configured for more than one word otherwise
> the DMA will fail in buffer configuration where the sizes are not
> aligned with the requested FIFO configuration.

Oh, I edited the commit message and removed the text related to buffer size
but I failed to do that for the commit title :(

Mark: Do you want me to resend with fixed commit title?

-- 
Péter

> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
> ---
>  sound/soc/davinci/davinci-mcasp.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c
> index a01ae97c90aa..df067a836c4d 100644
> --- a/sound/soc/davinci/davinci-mcasp.c
> +++ b/sound/soc/davinci/davinci-mcasp.c
> @@ -720,6 +720,7 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
>  				 struct snd_soc_dai *dai)
>  {
>  	struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(dai);
> +	int afifo_numevt;
>  
>  	if (mcasp->version == MCASP_VERSION_4)
>  		snd_soc_dai_set_dma_data(dai, substream,
> @@ -727,6 +728,16 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
>  	else
>  		snd_soc_dai_set_dma_data(dai, substream, mcasp->dma_params);
>  
> +	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
> +		afifo_numevt = mcasp->txnumevt;
> +	else
> +		afifo_numevt = mcasp->rxnumevt;
> +
> +	if (afifo_numevt > 1)
> +		snd_pcm_hw_constraint_step(substream->runtime, 0,
> +					   SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
> +					   afifo_numevt);
> +
>  	return 0;
>  }
>  
>