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

From: Takashi Iwai
Date: Tue Jul 31 2018 - 09:56:56 EST


On Tue, 31 Jul 2018 15:51:15 +0200,
Mark Brown wrote:
>
> On Tue, Jul 31, 2018 at 03:29:35PM +0200, Takashi Iwai wrote:
> > Mark Brown wrote:
>
> > > > > However since it's not supposed to be providing any DMA a CPU DAI really
> > > > > shouldn't be doing this...
>
> > > > Well, if so, the CPU dai also cannot get the exact base delay
> > > > corresponding to the reported position, either, no?
>
> > > It can know how much delay it's adding internally between its input and
> > > output, which feeds into the overall delay experienced by the user.
>
> > But isn't it merely the additional delay that should be applied on top
> > of the existing runtime->delay?
>
> Yes. I'm saying that if the CPU DAI thinks it can figure out the base
> delay something is confused.

Then basically Akshu's patch does the correct thing, I suppose.


Takashi