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Date:   Wed, 15 Jul 2020 14:03:08 -0700
From:   Nicolin Chen <nicoleotsuka@gmail.com>
To:     Mark Brown <broonie@kernel.org>
Cc:     Arnaud Ferraris <arnaud.ferraris@collabora.com>,
        alsa-devel@alsa-project.org, Timur Tabi <timur@kernel.org>,
        Xiubo Li <Xiubo.Lee@gmail.com>, linux-kernel@vger.kernel.org,
        Takashi Iwai <tiwai@suse.com>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Rob Herring <robh+dt@kernel.org>, kernel@collabora.com,
        Fabio Estevam <festevam@gmail.com>
Subject: Re: [PATCH 0/4] ASoC: fsl_asrc: allow selecting arbitrary clocks
Message-ID: <20200715210308.GA14589@Asurada-Nvidia>
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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...