Subject: Re: ACPI suspend support.
To: Jared D. McNeill <jmcneill@invisible.ca>
From: Kentaro A. Kurahone <kurahone@sigusr1.org>
List: tech-kern
Date: 01/26/2005 01:31:15
On Tue, Jan 25, 2005 at 09:19:34PM -0400, Jared D. McNeill wrote:
> On Tue, 2005-01-25 at 17:00 -0800, Jason Thorpe wrote:
> > On Jan 25, 2005, at 4:18 PM, Matt Thomas wrote:
> > 
> > > Well, you almost want the driver to soft-detach, and then go
> > > through autoconf again on power-on giving preferences to those
> > > things that soft-detached.
> > 
> > That really kind of depends on what sort of bus you're talking about, 
> > but yah, that's also true.
> > 
> > (You certainly want to do that with USB, 1394, etc.)
> 
> What about the case of a umass device where we have a filesystem mounted
> from it? Should we unmount before sleeping, or handle this device
> differently? (I ask because I'm looking into a suitable powerhook for
> piixide in ACPI S3 sleep right now, and I can't very well unmount the
> root filesystem before suspending).

For piixide, you shouldn't need to.  Just saveoff/restore the pci config
space, and thwack the controller.

-- 
Kentaro A. Kurahone
SIGUSR1 Research and Development