[Intel-gfx] [3.0-rc3] i915: potentially stale ring data during resume

[Daniel J Blueman]

Hi Eric, Chris,

There are quite a lot of callers of I915_READ/WRITE which aren't
holding the dev->struct_mutex lock across device suspend and resume
operations, to prevent the GT going to sleep early if two callers are
in the gen6_gt_force_wake_get->gen6_gt_force_wake_put critical region.

I started cooking up a patch, but ran out of time.

Thanks,
  Daniel
-- 
Daniel J Blueman