Re: [PATCH] PM: add: move warn message out of mutex lock.

[Rafael J. Wysocki]

On Tue, Sep 3, 2024 at 3:01 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
>
> On Mon, Sep 2, 2024 at 7:50 AM David Wang <00107082@xxxxxxx> wrote:
> >
> > dpm_list_mtx does not protect any data used by
> > dev_warn for checking parent's power, move
> > dev_warn out of mutex lock block make the
> > lock more efficient, especially when the warn
> > is triggered.
>
> It does protect the power.is_prepared flag of the parent.

In fact, the update of it in device_resume() is racy with respect to
the check in device_pm_add(), but the purpose of it is mostly to allow
the device driver's resume callback to add children without triggering
the warning.