Intel i915 freeze on latest git

[Jesse Barnes]

On Thu, 10 Feb 2011 13:10:26 +0100
Francesco Allertsen <fallertsen at gmail.com> wrote:

> On Wed, Feb 09, 2011 at 05:09:10PM +0000, Chris Wilson wrote:
> > 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 at 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 at gmail.com>
> >     Reported-by: Gui Rui <chaos.proton at gmail.com>
> >     Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=28582
> >     Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > 
> > That should work its way upstream shortly.
> 
> I've tried to apply it on top of 2.6.38-rc4, and now it doesn't hang
> when I start X, but it hangs when I resume from suspend to RAM.

Since intel_reg_read won't work, can you try this patch instead?  Just
patch it in, then cat /sys/kernel/debug/dri/0/i915_drpc_info

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

--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1018,6 +1018,8 @@ static int i915_drpc_info(struct seq_file *m, void *unused
                break;
        }
 
+       seq_printf(m, "RSTDBYCTL: 0x%08x\n", rstdbyctl);
+
        return 0;
 }