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authorTakashi Iwai <tiwai@suse.de>2012-06-21 15:30:41 +0200
committerBen Hutchings <ben@decadent.org.uk>2012-07-04 05:44:27 +0100
commit69d1e4c856fd460c37c3eb58996f69dc9add8111 (patch)
treebbe54cb6e487e6086900b304cc81a5c8d3a7051d /drivers
parent8bd2f25de46602be06dbce1c5daca376cfd6ed8b (diff)
drm/i915: Fix eDP blank screen after S3 resume on HP desktops
commit 6db65cbb941f9d433659bdad02b307f6d94465df upstream. This patch fixes the problem on some HP desktop machines with eDP which give blank screens after S3 resume. It turned out that BLC_PWM_CPU_CTL must be written after BLC_PWM_CPU_CTL2. Otherwise it doesn't take effect on these SNB machines. Tested with 3.5-rc3 kernel. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=49233 Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/i915/i915_suspend.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
index a1eb83dc07db..f38d196dda2d 100644
--- a/drivers/gpu/drm/i915/i915_suspend.c
+++ b/drivers/gpu/drm/i915/i915_suspend.c
@@ -739,8 +739,11 @@ static void i915_restore_display(struct drm_device *dev)
if (HAS_PCH_SPLIT(dev)) {
I915_WRITE(BLC_PWM_PCH_CTL1, dev_priv->saveBLC_PWM_CTL);
I915_WRITE(BLC_PWM_PCH_CTL2, dev_priv->saveBLC_PWM_CTL2);
- I915_WRITE(BLC_PWM_CPU_CTL, dev_priv->saveBLC_CPU_PWM_CTL);
+ /* NOTE: BLC_PWM_CPU_CTL must be written after BLC_PWM_CPU_CTL2;
+ * otherwise we get blank eDP screen after S3 on some machines
+ */
I915_WRITE(BLC_PWM_CPU_CTL2, dev_priv->saveBLC_CPU_PWM_CTL2);
+ I915_WRITE(BLC_PWM_CPU_CTL, dev_priv->saveBLC_CPU_PWM_CTL);
I915_WRITE(PCH_PP_ON_DELAYS, dev_priv->savePP_ON_DELAYS);
I915_WRITE(PCH_PP_OFF_DELAYS, dev_priv->savePP_OFF_DELAYS);
I915_WRITE(PCH_PP_DIVISOR, dev_priv->savePP_DIVISOR);