Re: [PATCH 2/2] ASoC: codecs: soundwire: call pm_runtime_resume() in component probe

[Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>]

On 6/17/22 14:05, Pierre-Louis Bossart wrote:
> 
>>>> What this patch does it make sure that the bus is operation when the
>>>> card is created. In usual cases, this is a no-op, this just helps with
>>>> corner test cases. It's not plugging a major hole in the pm_runtime
>>>> support, just fixing a programming sequence that was not tested before.
>>>
>>>> One possible objection is that we don't keep the reference and the bus
>>>> active until all components are probed. I tried doing this at the ASoC
>>>> core level, but that breaks all kinds of devices that have their own
>>>> quirky way of dealing with pm_runtime - specifically HDaudio and HDMI.
>>>> That's why I added this resume here.
>>>
>>>> Makes sense?
>>>
>>> Ish.  Ugh, right.  So it's not fixing anything really, it's mainly
>>> papering over cracks where things are being missed.  In any case it's
>>> not doing any harm and it helps things for now.
>>
>> You got it right. There are additional patches that were sent to use
>> pm_runtime_resume_and_get() on set_jack, and other clear cases that were
>> missed, but this is more of a blanket "do not harm" resume in case codec
>> drivers are missing something.
> 
> please wait for merges, we're chasing two regressions with nonsensical
> mixer values
> 
> numid=5,iface=MIXER,name='PGA4.0 4 Master Capture Volume'
>   ; type=BOOLEAN,access=rw---R--,values=2
>   : values=on,on
>   | dBscale-min=-50.00dB,step=1.00dB,mute=1
> 
> and a spurious log that we missed:
> 
> snd-soc-dummy snd-soc-dummy: Runtime PM usage count underflow!

The two regressions are not caused by this series.

The mixer issue already exists and is fixed with Sameer Pujar's "ASoC:
ops: Fix multiple value control type" patch.

The "Runtime PM usage count underflow" is a mistake on my side, the
patch "ASoC: soc-component: use pm_runtime_resume_and_get()" is invalid
and shall not be merged.

No other problem detected.