drm/i915: save/restore BLC histogram control reg across suspend/resume

Turns out some machines, like the ThinkPad X40 don't come back if you
don't save/restore this register.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 24e154e47225..f6a3587ad065 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -304,6 +304,7 @@ typedef struct drm_i915_private {
         u32 saveDSPASURF;
         u32 saveDSPATILEOFF;
         u32 savePFIT_PGM_RATIOS;
+        u32 saveBLC_HIST_CTL;
         u32 saveBLC_PWM_CTL;
         u32 saveBLC_PWM_CTL2;
         u32 saveFPB0;