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From:   Shengjiu Wang <shengjiu.wang@gmail.com>
Date:   Fri, 26 Feb 2021 14:05:29 +0800
Message-ID: <CAA+D8AO8_ESHSyODXhx4Wf1Z5MbtxWRUa-k2d6wKSeA0yzD5uA@mail.gmail.com>
Subject: Re: [PATCH] ASoC: simple-card: Add dummy dai support simple sound card
To:     Mark Brown <broonie@kernel.org>
Cc:     Shengjiu Wang <shengjiu.wang@nxp.com>,
        guennadi.liakhovetski@linux.intel.com, alsa-devel@alsa-project.org,
        kai.vehmanen@linux.intel.com, stephan@gerhold.net,
        Liam Girdwood <lgirdwood@gmail.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
        Takashi Iwai <tiwai@suse.com>
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On Thu, Feb 25, 2021 at 9:17 PM Mark Brown <broonie@kernel.org> wrote:
>
> On Thu, Feb 25, 2021 at 08:08:32PM +0800, Shengjiu Wang wrote:
>
> > If sound card doesn't need specific codec device, just
> > dummy codec is enough, then we can link the dummy component
> > directly.
>
> This is a big red flag - what circumstances are these?  If it's a simple
> CODEC with no control then the general approach is to provide a driver
> which announces the capabilities of the CODEC and can be bound to as
> normal, the dummy component should never actively be used.

For the DMIC, SPDIF, HDMI ARC device or other
similar device that there is no codec connected,  then dummy codec is
just used for registering the sound card.

best regards
wang shengjiu