Re: [PATCH 6/6] USB / PM: Allow USB devices to remain runtime-suspended when sleeping

From: Oliver Neukum
Date: Wed Apr 01 2015 - 10:27:33 EST


On Wed, 2015-04-01 at 10:01 -0400, Alan Stern wrote:
> On Wed, 1 Apr 2015, Oliver Neukum wrote:
>
> > On Tue, 2015-03-31 at 13:09 -0400, Alan Stern wrote:
> > > In other words, if the device is currently in runtime suspend with
> > > remote wakeup enabled, but device_may_wakeup() returns 0 (so that the
> > > device should be disabled for wakeup when the system goes into
> > > suspend), then the prepare callback has to return 0.
> > >
> > > Therefore what you need to do here is something like this:
> > >
> > > struct usb_device *udev = to_usb_device(dev);
> > >
> > > /* Return 0 if the current wakeup setting is wrong, otherwise
> > > 1 */
> >
> > And the other way round?
>
> Your meaning isn't clear. Are you asking what should happen if the
> device is in runtime suspend with remote wakeup disabled, but
> device_may_wakeup() returns 1?

Yes. I was thinking about that case.

> That case should never happen -- but
> if it does then the prepare callback should return 0.

Exactly. It didn't seem to do so.

Regards
Oliver





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