[RFC v2 4/7] ASoC: dmaengine_pcm: add copy support

[Arnaud Pouliquen]

Hello Mark,

Sorry for the late answer, i was OoO...

On 02/16/2017 09:14 PM, Mark Brown wrote:
> On Wed, Feb 15, 2017 at 04:46:44PM +0100, Arnaud Pouliquen wrote:
>> On 02/15/2017 03:53 PM, Mark Brown wrote:
>>> On Wed, Feb 15, 2017 at 02:59:18PM +0100, Arnaud Pouliquen
>>> wrote:
> 
>>> No, copy() is an alternative to doing DMA rather than
>>> something that works with DMA.  If you want to have some sort
>>> of post processing operation it shoudn't be called copy().
>>> It's probably worth considering just making a new format and
>>> letting userspace convert things here.
> 
>> You mean using a plug-in alsa to do it? this seems not possible
>> with tiny-alsa... Without a plug-in, driver will not be
>> compatible with standard audio application.
> 
> Right.  But if you're using tinyalsa you've got some open coded
> system specific stuff anyway!
> 
>> Do you think this would be reasonable if i implement something
>> similar in my driver, without using the soc generic DMA engine?
> 
> Probably.  It might even be possible to fit it elegently into the 
> generic dmaengine code, just don't say it's a copy() operation
> since that's a specific thing in ALSA.
> 
Ok I will have a look in generic dmaengine and try to propose
something in this way in the V2.

Regards,
Arnaud