Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8)

Matthew Garrett
2010-05-27T18:29:31Z

On Thu, May 27, 2010 at 08:18:11PM +0200, Peter Zijlstra wrote:
> On Thu, 2010-05-27 at 19:14 +0100, Matthew Garrett wrote:
> > If I get a WoL
> > packet in the 0.5 of a second between userspace deciding to suspend and
> > actually doing so, the system shouldn't suspend.
>
> Please re-read Thomas' description of how a driver should do the state
> transition.
>
> So either we get the packet before suspend, and we cancel the suspend,
> or we get it after and we wake up. What's the problem, and how does that
> need suspend blockers?

In order to cancel the suspend we need to keep track of whether
userspace has consumed the event and reacted appropriately. Since we
can't do this with the process scheduler, we end up with something that
looks like suspend blockers.

--
Matthew Garrett | mjg59@srcf.ucam.org