Hi,
On 6/10/24 1:56 PM, Jai Luthra wrote:
> The minimum period size was enforced to 64 as older devices integrating
> McASP with EDMA used an internal FIFO of 64 samples.
>
> With UDMA based platforms this internal McASP FIFO is optional, as the
> DMA engine internally does some buffering which is already accounted for
> when registering the platform. So we should read the actual FIFO
> configuration (txnumevt/rxnumevt) instead of hardcoding frames.min to
> 64.
Thank you the patch and the fix,
Acked-by: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>
>
> Signed-off-by: Jai Luthra <j-luthra@xxxxxx>
> ---
> sound/soc/ti/davinci-mcasp.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/sound/soc/ti/davinci-mcasp.c b/sound/soc/ti/davinci-mcasp.c
> index 1e760c315521..2b1ed91a736c 100644
> --- a/sound/soc/ti/davinci-mcasp.c
> +++ b/sound/soc/ti/davinci-mcasp.c
> @@ -1472,10 +1472,11 @@ static int davinci_mcasp_hw_rule_min_periodsize(
> {
> struct snd_interval *period_size = hw_param_interval(params,
> SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
> + u8 numevt = *((u8 *)rule->private);
> struct snd_interval frames;
>
> snd_interval_any(&frames);
> - frames.min = 64;
> + frames.min = numevt;
> frames.integer = 1;
>
> return snd_interval_refine(period_size, &frames);
> @@ -1490,6 +1491,7 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
> u32 max_channels = 0;
> int i, dir, ret;
> int tdm_slots = mcasp->tdm_slots;
> + u8 *numevt;
>
> /* Do not allow more then one stream per direction */
> if (mcasp->substreams[substream->stream])
> @@ -1589,9 +1591,12 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
> return ret;
> }
>
> + numevt = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
> + &mcasp->txnumevt :
> + &mcasp->rxnumevt;
> snd_pcm_hw_rule_add(substream->runtime, 0,
> SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
> - davinci_mcasp_hw_rule_min_periodsize, NULL,
> + davinci_mcasp_hw_rule_min_periodsize, numevt,
> SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
>
> return 0;
>
--
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