Re: Intel i915 freeze on latest git

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Wed, 9 Feb 2011 09:53:26 -0800
Jesse Barnes <jbarnes@virtuousgeek.org> wrote:

> On Wed, 9 Feb 2011 09:50:47 -0800
> Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
> 
> > On Wed, 09 Feb 2011 17:09:10 +0000
> > Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > 
> > > On Wed, 9 Feb 2011 13:52:38 +0100, Francesco Allertsen <fallertsen@gmail.com> wrote:
> > > > On Wed, Feb 02, 2011 at 09:59:54AM +0000, Chris Wilson wrote:
> > > > > Hmm, that was the only change I could spot between the two patches. Care
> > > > > to disable that function and see what happens? [i.e. put a return before
> > > > > we write anything to the ring]
> > > > 
> > > > Ping?
> > > 
> > > I was optimistic that we might spot the real issue... However, you appear
> > > to be not alone and so I've pushed a disabling patch onto -fixes:
> > > 
> > > commit ac66808814036b4c33dd98091b2176ae6157f1a8
> > > Author: Chris Wilson <chris@chris-wilson.co.uk>
> > > Date:   Wed Feb 9 16:15:32 2011 +0000
> > > 
> > >     drm/i915: Disable RC6 on Ironlake
> > >     
> > >     The automatic powersaving feature is once again causing havoc, with 100%
> > >     reliable hangs on boot and resume on affected machines.
> > >     
> > >     Reported-by: Francesco Allertsen <fallertsen@gmail.com>
> > >     Reported-by: Gui Rui <chaos.proton@gmail.com>
> > >     Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=28582
> > >     Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> > > 
> > > That should work its way upstream shortly.
> > 
> > reverting the cleanup wasn't sufficient?
> > 
> > Francesco, if you revert the cleanup patch you bisected to, what
> > does /sys/kernel/debug/dri/0/i915_drpc_info report?
> 
> In particular, I'm curious if it reports that you're in RC6, so you
> might need to cat it a couple of times while gfx is idle (like from the
> console or an ssh session while nothing is drawing).

Oh and one more request, what does "intel_reg_read 0x111b8" return on
your system?

I really don't want to disable RC6; it saves way too much power.  So
I'd like to understand what's going on here so we can either fix your
system or reliably find a way to disable it on systems where the BIOS
isn't allowing it...

Thanks,
-- 
Jesse Barnes, Intel Open Source Technology Center