[Regression, post-2.6.34] Hibernation broken on machines with radeon/KMS and r300

[Rafael J. Wysocki]

On Wednesday, June 16, 2010, Ondrej Zary wrote:
> On Wednesday 16 June 2010, Rafael J. Wysocki wrote:
> > On Tuesday, June 15, 2010, Rafael J. Wysocki wrote:
> > > On Monday, June 14, 2010, Alex Deucher wrote:
> > > > On Mon, Jun 14, 2010 at 3:03 PM, Rafael J. Wysocki <rjw at sisk.pl> wrote:
> > > > > On Monday, June 14, 2010, Alex Deucher wrote:
> > > > >> On Mon, Jun 14, 2010 at 10:53 AM, Rafael J. Wysocki <rjw at sisk.pl> 
> wrote:
> > > > >> > Alex, Dave,
> > > > >> >
> > > > >> > I'm afraid hibernation is broken on all machines using radeon/KMS
> > > > >> > with r300 after commit ce8f53709bf440100cb9d31b1303291551cf517f
> > > > >> > (drm/radeon/kms/pm: rework power management).  At least, I'm able
> > > > >> > to reproduce the symptom, which is that the machine hangs hard
> > > > >> > around the point where an image is created (probably during the
> > > > >> > device thaw phase), on two different boxes with r300 (the output
> > > > >> > of lspci from one of them is attached for reference, the other one
> > > > >> > is HP nx6325).
> > > > >> >
> > > > >> > Suspend to RAM appears to work fine at least on one of the
> > > > >> > affected boxes.
> > > > >> >
> > > > >> > Unfortunately, the commit above changes a lot of code and it's not
> > > > >> > too easy to figure out what's wrong with it and I didn't have the
> > > > >> > time to look more into details of this failure.  However, it looks
> > > > >> > like you use .suspend() and .resume() callbacks as .freeze() and
> > > > >> > .thaw() which may not be 100% correct (in fact it looks like the
> > > > >> > "legacy" PCI suspend/resume is used, which is not recommended any
> > > > >> > more).
> > > > >>
> > > > >> Does it work any better after Dave's last drm pull request?
> > > > >
> > > > > Nope.  The symptom is slightly different, though, because now it
> > > > > hangs after turning off the screen.
> > > > >
> > > > >> With the latest changes, pm should not be a factor unless it's
> > > > >> explicitly enabled via sysfs.
> > > > >
> > > > > Well, I guess the first pm patch changed more than just pm, then.
> > > >
> > > > Does this patch help?
> > > > http://lists.freedesktop.org/archives/dri-devel/2010-June/001314.html
> > >
> > > No, it doesn't.  I try to hibernate, everything works to the point where
> > > the screen goes off and the box hangs (solid).  Normally, it would turn
> > > the screen back on and continue with saving the image.
> > >
> > > But, since that happens with the patch above applied, I think it doesn't
> > > really pass the suspend phase (IOW, it probably hangs somewhere in the
> > > radeon's suspend routine).
> >
> > I've just verified that in fact hibernation works on HP nx6325 with
> > 2.6.35-rc3, but it takes about 55 sec. to suspend the graphics adapter in
> > the "freeze" phase.  Surprisingly enough, during suspend to RAM it works
> > normally (as well as in the "poweroff" phase of hibernation).
> 
> It takes 2 minutes on RV530: 
> https://bugzilla.redhat.com/show_bug.cgi?id=586522

Well, my second affected box appears to hang somewhere in the radeon's suspend
routine.

Rafael