tree 973f16debeeee5678268e502b827f704f9d973f0
parent 5ed1678206a392ac509cd1f6415df74b9008aa9a
author Chris Wilson <chris@chris-wilson.co.uk> 1385152524 +0000
committer Daniel Vetter <daniel.vetter@ffwll.ch> 1385458075 +0100

drm/i915: Drop forcewake w/a for missed interrupts/seqno on Sandybridge

I believe, and an evening of i-g-t, that our original workaround for the
missed interrupts on Sandybridge, that of holding forcewake whilst we
wait for an interrupts, is no longer required. This leaves us dependent
on the second workaround of forcing an UC read of the ACTHD before
reading back the seqno from the snooped HWS. Dropping the forcewake
should allow us to conserve a little power, not much as the GPU is meant
to be busy whilst we wait for it!

Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>