[alsa-devel] [PATCH] ASoC: atmel-pcm-dma: Remove SND_DMAENGINE_PCM_FLAG_NO_RESIDUE flag

Lars-Peter Clausen lars at metafoo.de
Tue Jan 7 10:15:51 CET 2014

On 01/07/2014 10:05 AM, Bo Shen wrote:
> Hi Lars,
> On 01/06/2014 10:30 PM, Lars-Peter Clausen wrote:
>> Since commit d48de6f1a ("DMA: AT91: Get residual bytes in dma buffer") the
>> at91-dma driver has support for residue reporting. So there is no need to
>> specify the SND_DMAENGINE_PCM_FLAG_NO_RESIDUE flag. This allows for a finer
>> grained resolution of the PCM pointer as well as avoids the race condition
>> that
>> can occur with the period counting that is used when the dmaengine driver
>> does
>> not support residue reporting.
>> Signed-off-by: Lars-Peter Clausen <lars at metafoo.de>
>> ---
>> I don't have the hardware, so only compile tested. It should work though
>> if the
>> residue calculation in the dma driver is implemented correctly.
>> ---
>>   sound/soc/atmel/atmel-pcm-dma.c | 3 +--
>>   1 file changed, 1 insertion(+), 2 deletions(-)
> Thanks for your patch.
> For the dma get residue code, we are improving it. So, I think we'd better
> waiting the improvement done and after let this patch go into mainline.
> What do you think?

If the residue reporting in the dmaengine driver doesn't work properly yet
we have to wait.

- Lars

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