tree 9f0029d3410fe4b6c96253ce467e6071ad0db7c6
parent 4fc688ce79772496503d22263d61b071a8fb596e
author Jesse Barnes <jbarnes@virtuousgeek.org> 1351880042 -0700
committer Daniel Vetter <daniel.vetter@ffwll.ch> 1352674302 +0100

drm/i915: don't rewrite the GTT on resume v4

The BIOS shouldn't be touching this memory across suspend/resume, so
just leave it alone.  This saves us ~6ms on resume on my T420 (retested
with write combined PTEs).

v2: change gtt restore default on pre-gen4 (Chris)
    move needs_gtt_restore flag into dev_priv
v3: make sure we restore GTT on resume from hibernate (Daniel)
    use opregion support as the cutoff for restore from resume (Chris)
v4: use a better check for opregion (Chris)

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Kill the needs_gtt_restore indirection and check directly for
OpRegion. Also explain in a comment what's going on.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>