Re: [PATCH] Revert "ALSA: hda: call runtime_allow() for all hda controllers"

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

>>>> Do I get this right that this permanently disables pm_runtime on all
>>>> Intel HDaudio controllers?
>>>
>>> It just drops the unconditional enablement of runtime PM.
>>> It can be enabled via sysfs, and that's the old default (let admin
>>> enabling it via udev or whatever).
>>
>> Sorry I am confused now.
>> Kai seemed to suggest in the Bugzilla comments that this would be
>> temporary, until these problems with i915 and ALC662 get fixed?
> 
> Right, that's the plan.  This patch revert to the old state before the
> forced-all-enable call we've taken in 5.7.  On 5.7 and onwards, all
> HD-audio controllers are enforced to use the runtime PM.  Before that
> version, the runtime PM was enabled *as default* only for limited
> devices (typically the ones bound with GPU); for other devices, the
> runtime PM is manually enabled from user-space via sysfs (and many
> distros enable them in anyway).
> 
> The forced enablement was merged with a hope that now all HD-audio
> controllers behave nicely, but it turned out to cause a regression, so
> it was reverted.  Once when we find out the real cause, we can flip
> the flag again.

ok, sounds good. I was concerned mainly because on the SOF driver side 
we enable pm_runtime by default, so that's a difference in configuration 
we need to be aware of when dealing with 'my speaker is silent' support 
questions.