Re: [PATCH] ASoC: SDCA: Add NO_DIRECT_COMPLETE flag to class driver

[Charles Keepax <ckeepax@opensource.cirrus.com>]

On Wed, Jan 21, 2026 at 01:41:31PM +0100, Pierre-Louis Bossart wrote:
> >> Going back to this SDCA driver, if the PM core does NOT
> >> change the pm_runtime state, then should the class driver
> >> perform a full pm_runtime resume and then do the expected
> >> system suspend sequence?
> > 
> > Yeah we do perform a resume in the system suspend although to be
> > honest its mostly just to force the pm_runtime_force_resume() in
> > the system resume handler to always do a runtime resume.
> 
> I think we are talking about different actions...
> 
> a) pm_runtime resume BEFORE system suspend. That would be
> necessary to deal with e.g. clock stop modes that are valid in
> pm_runtime suspend but not system suspend. It's not clear to me
> for example if all SDCA chips will support direct transitions
> from PS3 to PS4, or be ok with power rails cut while in PS3.

I mean I think this is currently handled at the soundwire level,
since the soundwire bus runtime resumes all children for system
suspend.

> You lost me with this sentence:
> 
> "
> For SoundWire itself the soundwire host resumes all children
> before a suspend, which dodges the direct complete.
> "
> 
> If the direct-complete optimization is not used, then do you
> actually see a different behavior with this NO_DIRECT_COMPLETE
> flag set?

The flag is applied to the auxiliary device children of the
soundwire device. The direct complete doesn't affect the
soundwire device, but it it does affect the function devices
children.

Thanks,
Charles