Re: [PATCH 0/4] ASoC: fsl_asrc: allow selecting arbitrary clocks

From: Nicolin Chen
Date: Wed Jul 15 2020 - 17:03:35 EST


On Wed, Jul 15, 2020 at 03:05:19PM +0100, Mark Brown wrote:
> On Tue, Jul 14, 2020 at 01:50:50PM -0700, Nicolin Chen wrote:
> > On Tue, Jul 14, 2020 at 09:27:53PM +0100, Mark Brown wrote:
>
> > > The nominal rate might be the same but if they're in different clock
> > > domains then the actual rates might be different (hence the desire for
> > > an ASRC I guess). I can see the system wanting to choose one clock or
> > > the other on the basis of some system specific property (quality of the
> > > clock sources, tolerances of the devices involved or something) though
> > > it's a rather fun edge case configuration :/ .
>
> > Thanks for the input. Fox i.MX6, I don't feel it would be that
> > drastically different though. And both SSI1 and SSI2 can simply
> > select the same root clock source to avoid that happen.
>
> If you've got two radios that both need to sync to some radio derived
> frequency it gets a bit more entertaining.

I'm simply curious what could be a problem. Do you mind educating
me a bit? And ASRC here isn't a radio but a sample rate converter
working as a BE in DPCM setup, using radio-capture for example...