Re: [linux-pm] Re: [PATCH] PM: Acquire device locks on suspend

Rafael J. Wysocki
2008-01-06T23:57:07Z

On Monday, 7 of January 2008, Johannes Berg wrote:
> Rafael J. Wysocki wrote:
>
> >> I don't see anything wrong with it. All that will happen is that the
> >> removal will start before the suspend and finish after the resume.
> >
> > In that case, we'll attempt to call the device's .suspend() and .resume()
> > routines, but we shouldn't do that, IMHO.
>
> I don't see anything wrong with that since the driver must be prepared to
> handle that even in the regular case, it's the only thing you can
> guarantee: no more method calls after removal finishes. Am I totally
> misunderstanding things?

Well, we are towards the end of device removal at this point, having called
bus_remove_device(dev) for example, but still we've got it on dpm_active ...

This may not be technically wrong (ie. we should be able to recover from
that), but it seems conceptually wrong and with pm_sleep_rwsem in place it
can be avoided.

Rafael