[drm:hsw_unclaimed_reg_detect] *ERROR* Unclaimed register detected. Please use the i915.mmio_debug=1 to debug this problem.

[Daniel Vetter]

On Mon, Dec 15, 2014 at 10:24:53AM +0100, Toralf Förster wrote:
> On 12/15/2014 08:45 AM, Daniel Vetter wrote:
> > Nah, this is just a kernel cmdlineoption. So please boot with
> > i915.mmio_debug=1 added to the kernel cmdline, reproduce and then grab the
> > entire dmesg.
> > 
> > Thanks, Daniel
> 
> errm, I did it, rebooted, suspended and then the WARNING appeared:
> 
> >Dec 12 13:22:13 t44 kernel: ------------[ cut here ]------------
> >Dec 12 13:22:13 t44 kernel: WARNING: CPU: 3 PID: 2750 at drivers/gpu/drm/i915/intel_uncore.c:528 hsw_unclaimed_reg_debug.isra.11+0x8d/0xa0 [i915]()

Annoying, the unclaimed register write seems to happen before we do
anything really. Can you please test what happens when you disable all
sound modules?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch