Re: [PATCH v1] PM: sleep: Do not flag runtime PM workqueue as freezable

[YangYang]

On 2025/12/2 3:58, Rafael J. Wysocki wrote:
> On Monday, December 1, 2025 7:47:46 PM CET Rafael J. Wysocki wrote:
> > On Mon, Dec 1, 2025 at 10:46 AM YangYang <yang.yang@xxxxxxxx> wrote:
>
> [cut]
>
> > If blk_queue_enter() or __bio_queue_enter() is allowed to race with
> > disabling runtime PM for q->dev, failure to resume q->dev is alway
> > possible and there are no changes that can be made to
> > pm_runtime_disable() to prevent that from happening.  If
> > __pm_runtime_disable() wins the race, it will increment
> > power.disable_depth and rpm_resume() will bail out when it sees that
> > no matter what.
> >
> > You should not conflate "runtime PM doesn't work when it is disabled"
> > with "asynchronous runtime PM doesn't work after freezing the PM
> > workqueue".  They are both true, but they are not the same.
>
> So I've been testing the patch below for a few days and it will eliminate
> the latter, but even after this patch runtime PM will be disabled in
> device_suspend_late() and if the problem you are facing is still there
> after this patch, it will need to dealt with at the driver level.
>
> Generally speaking, driver involvement is needed to make runtime PM and
> system suspend/resume work together in the majority of cases.

Thank you. I'll perform some tests with this patch applied.