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

Matthew Garrett
2010-05-27T21:36:35Z

On Thu, May 27, 2010 at 10:37:51PM +0100, Alan Cox wrote:
> On Thu, 27 May 2010 18:25:10 +0100
> Matthew Garrett <mjg59@srcf.ucam.org> wrote:
> > How (and why) does the WoL (which may be *any* packet, not just a magic
> > one) turn the screen back on?
>
> Well on my laptop today it works like this
>
> A WoL packet arrives
> The CPU resumes
> Depp process, chipset and laptop BIOS magic happens
> The kernel gets called
> The kernel lets interested people know a resume occurred

No it doesn't. The kernel continues executing anything that was on the
runqueue before the scheduler stopped. If you're using idle-based
suspend then there's nothing on the runqueue - the application that
should be scheduled because of the event is blocked on writing to the
screen.

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