Re: [PATCH 2/2] Fix console handling during suspend/resume

Pavel Machek
2006-06-15T18:03:50Z

On Čt 15-06-06 09:57:41, David Brownell wrote:
> On Thursday 15 June 2006 1:41 am, Pavel Machek wrote:
> > On St 14-06-06 18:46:55, David Brownell wrote:
> > > On Wednesday 14 June 2006 4:57 pm, Pavel Machek wrote:
> > >
> > > > My point is that you really want the console enabled in writing phase
> > > > of suspend-to-disk.
> > >
> > > Notice how nicely this generalizes a point that's been made before:
> > > Linux should have the ability to exclude certain devices (and their
> > > parents) from that first "prepare to suspend" phase. Originally the
> >
> > No, it does not. If your console needs DMA, you _need_ to stop it. If
> > it can work without, you want to keep it enabled.
> >
> > This has less to do with device types and trees and more to do with
> > DMA or not.
>
> Certainly there are details that need to be worked out, that's the
> whole point of fixing some of these console+suspend problems. And
> DMA is one of them.
>
> In this case, DMA only would need to be prevented during the actual
> construction of the snapshot -- which is AFTER that "prepare to
> suspend" phase, notice! -- so your straw-man doesn't apply.

Okay, you _can_ do

suspend whole tree but disk and video
freeze disk and video
create snapshot
unfreeze disk and video
write snapshot
powerdown

Question is: looks to me like quite a lot of complexity for very
little gain, but...
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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