[alsa-devel] [PATCH] ASoC: soc-pcm: Use delay set in pointer function

Agrawal, Akshu Akshu.Agrawal at amd.com
Tue Jul 31 03:25:06 CEST 2018



On 7/30/2018 9:20 PM, Mark Brown wrote:
> On Mon, Jul 30, 2018 at 05:32:21PM +0200, Takashi Iwai wrote:
> 
>> That said, if delay callback of CPU dai provides the additional delay,
>> the patch does correct thing.  OTOH, if CPU dai provides the base
>> delay instead, we need to clarify that it's rather a must; the delay
>> calculation in pointer callback becomes bogus in this scenario.
> 
> Part of the theory here is that every component might have a delay
> independently of the rest and we need to add them all together to figure
> out what the system as a whole will see.  Personally I'd rather just
> have everything use a callack consistently to avoid confusion.
> 

For consistency we can add a delay callback in snd_pcm_ops and modify
the drivers which directly assigning runtime->delay to use the callback.
Apart from the 2 drivers mentioned in commit message I also found
sound/usb to be doing the same and its delay getting lost.

Thanks,
Akshu


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