Re: [patch update] Re: [linux-pm] Run-time PM idea (was: Re: [RFC][PATCH 0/2] PM: Rearrange core suspend code)

[Oliver Neukum]

Am Donnerstag, 11. Juni 2009 15:48:33 schrieb Rafael J. Wysocki:
> > > But after pm_request_resume() returns there's no means to make sure
> > > nothing alters it back to RPM_SUSPENDED. The workqueue doesn't help
> > > you because you've scheduled nothing by that time. The suspension will
> > > work because C is still in RPM_SUSPENDED.
> >
> > This is an example where usage counters come in handy.
>
> Do you mean we can count suspend/resume requests for a device?

No, we count reasons a device cannot be suspended. Drivers are allowed to
add their own reasons. The core uses that mechanism to indicate that an
ongoing resumption lower down is also a reason.
The count going to zero is equivalent to a request to suspend.

	Regards
		Oliver

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