[Intel-gfx] [PATCH] drm/i915: Only warn the first time we attempt to mmio whilst suspended

[Chris Wilson]

On Mon, Nov 24, 2014 at 12:11:45PM -0200, Paulo Zanoni wrote:
> 2014-11-24 6:03 GMT-02:00 Chris Wilson <chris at chris-wilson.co.uk>:
> > In all likelihood we will do a few hundred errnoneous register
> > operations if we do a single invalid register access whilst the device
> > is suspended. As each instance causes a WARN, this floods the system
> > logs and can make the system unresponsive.
> >
> > The warning was first introduced in
> > commit b2ec142cb0101f298f8e091c7d75b1ec5b809b65
> > Author: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > Date:   Fri Feb 21 13:52:25 2014 -0300
> >
> >     drm/i915: call assert_device_not_suspended at gen6_force_wake_work
> >
> > and despite the claims the WARN is still encountered in the wild today.
> 
> Can you please give us some more information on the WARNs you are
> encountering? Any bug numbers? Which platforms? Do we have test cases
> for these in IGT? If you can describe the steps to reproduce, we can
> try to write some test cases.

23:52 < joecool> hey i am having a handful of issues with haswell on
3.17, one of them i keep seeing spammed in dmesg but nowhere else in
logs
00:09 < joecool> i should mention those warnings also appear pretty fast
when my lid is closed sometimes and screen is toggled off (it maxes my
syslog-ng process and often crashes laptop, not just X)

Now that seems to be a critical bug causing data loss. Please fix
immediately.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre