[alsa-devel] [PATCH 3/3] ASoC: omap-mcbsp: make minimum period size larger than FIFO

[Grazvydas Ignotas]

On Mon, Mar 12, 2012 at 2:41 PM, Peter Ujfalusi <peter.ujfalusi at ti.com> wrote:
> On 03/12/2012 02:05 PM, Grazvydas Ignotas wrote:
>> aplay -D hw:0 -f s16_le -c 2 --period-size=512 --start-delay=50000 /dev/urandom
>>
>> note that this will only show problems on OMAP3 McBSP2 due to it's long FIFO.
>
> There's something else here since:
> aplay -D hw:0 -fs16_le -c2 --period-size=320 --buffer-size=972 \
> --start-delay=81000 -v /dev/urandom
>
> Works correctly, however
> aplay -D hw:0 -fs16_le -c2 --period-size=324 --buffer-size=972 \
> --start-delay=81000 -v /dev/urandom
>
> produces underruns.
> In both cases the start_threshold is set to 648 (640 is the FIFO McBSP2
> size). Both should be fine, but period_size=324 underruns.
>
> So the issue is not that simple as it seams...

Seems to be affected --stop-delay, increasing it helps here, maybe
core stops it for too long.

-- 
Gražvydas