Re: [Resend][PATCH] PM: Move disabling/enabling runtime PM to latesuspend/early resume

From: Jiri Kosina
Date: Sat Dec 15 2012 - 16:16:28 EST


On Sat, 15 Dec 2012, Rafael J. Wysocki wrote:

> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> Currently, the PM core disables runtime PM for all devices right
> after executing subsystem/driver .suspend() callbacks for them
> and re-enables it right before executing subsystem/driver .resume()
> callbacks for them. This may lead to problems when there are
> two devices such that the .suspend() callback executed for one of
> them depends on runtime PM working for the other. In that case,
> if runtime PM has already been disabled for the second device,
> the first one's .suspend() won't work correctly (and analogously
> for resume).
>
> To make those issues go away, make the PM core disable runtime PM
> for devices right before executing subsystem/driver .suspend_late()
> callbacks for them and enable runtime PM for them right after
> executing subsystem/driver .resume_early() callbacks for them. This
> way the potential conflitcs between .suspend_late()/.resume_early()
> and their runtime PM counterparts are still prevented from happening,
> but the subtle ordering issues related to disabling/enabling runtime
> PM for devices during system suspend/resume are much easier to avoid.
>
> Reported-and-tested-by: Jan-Matthias Braun <jan_braun@xxxxxxx>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Hi Rafael,

just curious what is the reason for resend? Do you want to gather more
Acks before pushing this upstream?

Thanks.

--
Jiri Kosina
SUSE Labs
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