1 files changed, 16 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index c6629bd9430f..d1b4ece4df00 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -765,6 +765,12 @@ static void ironlake_edp_panel_on (struct drm_device *dev)
                 return;
 
         pp = I915_READ(PCH_PP_CONTROL);
+
+        /* ILK workaround: disable reset around power sequence */
+        pp &= ~PANEL_POWER_RESET;
+        I915_WRITE(PCH_PP_CONTROL, pp);
+        POSTING_READ(PCH_PP_CONTROL);
+
         pp |= PANEL_UNLOCK_REGS | POWER_TARGET_ON;
         I915_WRITE(PCH_PP_CONTROL, pp);
 
@@ -773,7 +779,9 @@ static void ironlake_edp_panel_on (struct drm_device *dev)
                           I915_READ(PCH_PP_STATUS));
 
         pp &= ~(PANEL_UNLOCK_REGS | EDP_FORCE_VDD);
+        pp |= PANEL_POWER_RESET; /* restore panel reset bit */
         I915_WRITE(PCH_PP_CONTROL, pp);
+        POSTING_READ(PCH_PP_CONTROL);
 }
 
 static void ironlake_edp_panel_off (struct drm_device *dev)
@@ -782,6 +790,12 @@ static void ironlake_edp_panel_off (struct drm_device *dev)
         u32 pp;
 
         pp = I915_READ(PCH_PP_CONTROL);
+
+        /* ILK workaround: disable reset around power sequence */
+        pp &= ~PANEL_POWER_RESET;
+        I915_WRITE(PCH_PP_CONTROL, pp);
+        POSTING_READ(PCH_PP_CONTROL);
+
         pp &= ~POWER_TARGET_ON;
         I915_WRITE(PCH_PP_CONTROL, pp);
 
@@ -790,8 +804,9 @@ static void ironlake_edp_panel_off (struct drm_device *dev)
                           I915_READ(PCH_PP_STATUS));
 
         /* Make sure VDD is enabled so DP AUX will work */
-        pp |= EDP_FORCE_VDD;
+        pp |= EDP_FORCE_VDD | PANEL_POWER_RESET; /* restore panel reset bit */
         I915_WRITE(PCH_PP_CONTROL, pp);
+        POSTING_READ(PCH_PP_CONTROL);
 }
 
 static void ironlake_edp_backlight_on (struct drm_device *dev)