Re: [PATCH 1/2] ASoC: q6afe-dai: add dummy register read function

Srinivas Kandagatla
2020-08-11T11:16:53Z

On 11/08/2020 12:04, Stephan Gerhold wrote:
> 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?
That should work, let me try that!

--srini
>
> 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
>