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From: Stephan Gerhold <stephan@gerhold.net>
To: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: broonie@kernel.org, alsa-devel@alsa-project.org,
	linux-kernel@vger.kernel.org, lgirdwood@gmail.com,
	tiwai@suse.com, john.stultz@linaro.org
Subject: Re: [PATCH 1/2] ASoC: q6afe-dai: add dummy register read function
Date: Tue, 11 Aug 2020 13:04:09 +0200	[thread overview]
Message-ID: <20200811110409.GA1481@gerhold.net> (raw)
In-Reply-To: <20200811102552.26975-1-srinivas.kandagatla@linaro.org>

On Tue, Aug 11, 2020 at 11:25:51AM +0100, Srinivas Kandagatla wrote:
> Most of the DAPM widgets for DSP ASoC components reuse reg field
> of the widgets for its internal calculations, however these are not
> real registers. So read/writes to these numbers are not really
> valid. However ASoC core will read these registers to get default
> state during startup.
> 

Actually q6afe-dai does not seem to make use of the register number.
The DAPM widgets all look like

  SND_SOC_DAPM_AIF_IN("HDMI_RX",  NULL,   0,    0,     0,      0),
                  /* (wname,    stname, wchan, wreg, wshift, winvert)

Wouldn't it be better to replace wreg = 0 with SND_SOC_NOPM in this case
so the read/write won't happen at all?

q6routing on the other hand does make use of wreg, so this would not
work there...

Also: If I remember correctly the ASoC core will also attempt to write
to these "registers" when starting to play some audio, so you might also
need to implement component->write().

Stephan

WARNING: multiple messages have this Message-ID (diff)
From: Stephan Gerhold <stephan@gerhold.net>
To: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: alsa-devel@alsa-project.org, lgirdwood@gmail.com, tiwai@suse.com,
	linux-kernel@vger.kernel.org, broonie@kernel.org,
	john.stultz@linaro.org
Subject: Re: [PATCH 1/2] ASoC: q6afe-dai: add dummy register read function
Date: Tue, 11 Aug 2020 13:04:09 +0200	[thread overview]
Message-ID: <20200811110409.GA1481@gerhold.net> (raw)
In-Reply-To: <20200811102552.26975-1-srinivas.kandagatla@linaro.org>

On Tue, Aug 11, 2020 at 11:25:51AM +0100, Srinivas Kandagatla wrote:
> Most of the DAPM widgets for DSP ASoC components reuse reg field
> of the widgets for its internal calculations, however these are not
> real registers. So read/writes to these numbers are not really
> valid. However ASoC core will read these registers to get default
> state during startup.
> 

Actually q6afe-dai does not seem to make use of the register number.
The DAPM widgets all look like

  SND_SOC_DAPM_AIF_IN("HDMI_RX",  NULL,   0,    0,     0,      0),
                  /* (wname,    stname, wchan, wreg, wshift, winvert)

Wouldn't it be better to replace wreg = 0 with SND_SOC_NOPM in this case
so the read/write won't happen at all?

q6routing on the other hand does make use of wreg, so this would not
work there...

Also: If I remember correctly the ASoC core will also attempt to write
to these "registers" when starting to play some audio, so you might also
need to implement component->write().

Stephan

  parent reply	other threads:[~2020-08-11 11:04 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-11 10:25 [PATCH 1/2] ASoC: q6afe-dai: add dummy register read function Srinivas Kandagatla
2020-08-11 10:25 ` Srinivas Kandagatla
2020-08-11 10:25 ` [PATCH 2/2] ASoC: q6routing: " Srinivas Kandagatla
2020-08-11 10:25   ` Srinivas Kandagatla
2020-08-11 11:04 ` Stephan Gerhold [this message]
2020-08-11 11:04   ` [PATCH 1/2] ASoC: q6afe-dai: " Stephan Gerhold
2020-08-11 11:16   ` Srinivas Kandagatla
2020-08-11 11:16     ` Srinivas Kandagatla
2020-08-11 11:36   ` Mark Brown
2020-08-11 11:36     ` Mark Brown

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