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>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 24e154e..f6a3587 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -304,6 +304,7 @@
u32 saveDSPASURF;
u32 saveDSPATILEOFF;
u32 savePFIT_PGM_RATIOS;
+ u32 saveBLC_HIST_CTL;
u32 saveBLC_PWM_CTL;
u32 saveBLC_PWM_CTL2;
u32 saveFPB0;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 0dd87a7..b481358 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1080,6 +1080,8 @@
#define BACKLIGHT_DUTY_CYCLE_SHIFT (0)
#define BACKLIGHT_DUTY_CYCLE_MASK (0xffff)
+#define BLC_HIST_CTL 0x61260
+
/* TV port control */
#define TV_CTL 0x68000
/** Enables the TV encoder */
diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
index 660c5f3..75c5bed 100644
--- a/drivers/gpu/drm/i915/i915_suspend.c
+++ b/drivers/gpu/drm/i915/i915_suspend.c
@@ -410,6 +410,7 @@
dev_priv->savePP_CONTROL = I915_READ(PP_CONTROL);
dev_priv->savePFIT_PGM_RATIOS = I915_READ(PFIT_PGM_RATIOS);
dev_priv->saveBLC_PWM_CTL = I915_READ(BLC_PWM_CTL);
+ dev_priv->saveBLC_HIST_CTL = I915_READ(BLC_HIST_CTL);
if (IS_I965G(dev))
dev_priv->saveBLC_PWM_CTL2 = I915_READ(BLC_PWM_CTL2);
if (IS_MOBILE(dev) && !IS_I830(dev))
@@ -501,6 +502,7 @@
I915_WRITE(PFIT_PGM_RATIOS, dev_priv->savePFIT_PGM_RATIOS);
I915_WRITE(BLC_PWM_CTL, dev_priv->saveBLC_PWM_CTL);
+ I915_WRITE(BLC_HIST_CTL, dev_priv->saveBLC_HIST_CTL);
I915_WRITE(PP_ON_DELAYS, dev_priv->savePP_ON_DELAYS);
I915_WRITE(PP_OFF_DELAYS, dev_priv->savePP_OFF_DELAYS);
I915_WRITE(PP_DIVISOR, dev_priv->savePP_DIVISOR);