Re: [linux-pm] wacom + runtime PM = AA deadlock

From: Oliver Neukum
Date: Tue Sep 14 2010 - 11:30:13 EST


Am Dienstag, 14. September 2010, 17:23:15 schrieb Alan Stern:
> On Tue, 14 Sep 2010, Oliver Neukum wrote:
>
> > > > Should I have used usb_autopm_get_interface_no_resume()?
> > >
> > > That actually would work. It's a good idea. The only drawback (not a
> > > big one) is that if the device _was_ suspended with remote wakeup
> > > enabled, doing this wouldn't turn off remote wakeup. I think that
> > > doesn't matter.
> >
> > I am afraid it does matter as devices whose remote wakeup is enabled
> > may draw more power.
>
> I doubt it, or at least, not very much more. They are still limited by
> the USB spec as to the total amount of current they can draw while
> suspended.

7.2.3 Sources of remote wakeup may draw 2.5mA when suspended
as opposed to 0.5 mA

Regards
Oliver
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