linux-kernel - Re: [PATCH 1/2] ASoC: codecs: Use component driver suspend/resume

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Message-ID: <56911e0e-0f25-4134-92fd-f89cb47fd9b6@sirena.org.uk>
Date: Wed, 29 Oct 2025 16:14:55 +0000
From: Mark Brown <broonie@...nel.org>
To: claudiu beznea <claudiu.beznea@...on.dev>
Cc: support.opensource@...semi.com, lgirdwood@...il.com, perex@...ex.cz,
	tiwai@...e.com, biju.das.jz@...renesas.com,
	prabhakar.mahadev-lad.rj@...renesas.com,
	linux-sound@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-renesas-soc@...r.kernel.org,
	Claudiu Beznea <claudiu.beznea.uj@...renesas.com>,
	stable@...r.kernel.org
Subject: Re: [PATCH 1/2] ASoC: codecs: Use component driver suspend/resume

On Wed, Oct 29, 2025 at 05:22:26PM +0200, claudiu beznea wrote:
> On 10/29/25 16:37, Mark Brown wrote:

> > The theory here is that the power management core uses the device
> > instantiation order for both suspend and resume (reversed on suspend) so
> > the fact that we use probe deferral to make sure that the card
> > components are ready should ensure that the card suspends before
> > anything in the card.  If that is no longer the case then we need to
> > ensure that all drivers have system PM ops which trigger the card, this
> > won't be a driver specific issue.

> I also saw the behavior described in this commit with the rz-ssi.c driver as
> well. The fix there was commit c1b0f5183a44 ("ASoC: renesas: rz-ssi: Use
> NOIRQ_SYSTEM_SLEEP_PM_OPS()").

> In case of this this codec, I saw the code in da7213_runtime_resume() and
> soc_resume_deferred() racing each other on system resume.

So I guess we need the more general fix then, with everything calling
into the core to suspend the cards.

> > If the device actually lost power during a runtime
> > suspend then we'll end up having a bad time.  There was also no mention
> > of runtime PM in the patch description...

> I had no issues with runtime PM, but only with suspend to RAM, when this
> function was called though
> struct dev_pm_ops::resume = pm_runtime_force_resume().

Calling regulator_disable() doesn't guarantee the regulator will be
disabled, the constraints or other devices can ensure that the device
retains power so there's no effect on the actual hardware.

> Would keeping the regcache_cache_only() + regcache_sync() here along with
> populating the struct snd_soc_component_driver::{suspend, resume} be an
> acceptable solution for you? I think that will work as well.

I'm not sure what you're intending to populate the component with there.

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