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

Mark Brown
2020-07-15T14:06:30Z

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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.

> Yet, in case that we need to support such an edge case, what's
> a relatively common practice to allow system select the clock
> source now?

Honestly for anything that fun it tends to be a custom machine driver.
A property would seem reasonable though.

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