[alsa-devel] [PATCH 19/19] ASoC: fsi: Add DMAEngine support

Lars-Peter Clausen lars at metafoo.de
Sat Feb 4 19:25:40 CET 2012

On 02/04/2012 07:06 PM, Vinod Koul wrote:
> On Sat, 2012-02-04 at 18:00 +0100, Lars-Peter Clausen wrote:
>> This is sort of what I have implemented right now. Although I also prepare and
>> submit the dma descriptor in trigger START instead of prepare. Mainly beacuse I
>> mapped trigger STOP to dmaengine_terminate_all. Or is issue_pending supposed to
>> just restart the transfer if it is circular, even though terminate_all has been
>> called?
> trigger START should not be used for preparing descriptors. You want to
> start to actually start the descriptor (which is issue_pending and NOT
> submit!!). You should do this is prepare callback.

I'm doing both, prepare+submit and issue_pending, because of what I wrote
above. Or can we assume that each call to the ALSA/ASoC prepare callback will
only be followed by at maximum one call to trigger START?

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