drm/i195/fbc: Add WaFbcNukeOnHostModify

Bspec states that we need to set nuke on modify all to prevent
screen corruption with fbc on skl and kbl.

v2: proper workaround name

References: HSD#2227109, HSDES#1404569388
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465309159-30531-27-git-send-email-mika.kuoppala@intel.com
(cherry picked from commit 031cd8c85aefad31e7af91eba7bc4735a6dfcc79)
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>

2 files changed, 11 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 235dfac9fe93..3b374284f739 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2206,6 +2206,7 @@ enum skl_disp_power_wells {
 #define ILK_DPFC_STATUS         _MMIO(0x43210)
 #define ILK_DPFC_FENCE_YOFF     _MMIO(0x43218)
 #define ILK_DPFC_CHICKEN        _MMIO(0x43224)
+#define   ILK_DPFC_NUKE_ON_ANY_MODIFICATION     (1<<23)
 #define ILK_FBC_RT_BASE         _MMIO(0x2128)
 #define   ILK_FBC_RT_VALID      (1<<0)
 #define   SNB_FBC_FRONT_BUFFER  (1<<1)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 61113a22bc89..074d6a53cc3e 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -6737,11 +6737,21 @@ static void kabylake_init_clock_gating(struct drm_device *dev)
         if (IS_KBL_REVID(dev_priv, 0, KBL_REVID_B0))
                 I915_WRITE(GEN6_UCGCTL1, I915_READ(GEN6_UCGCTL1) |
                            GEN6_GAMUNIT_CLOCK_GATE_DISABLE);
+
+        /* WaFbcNukeOnHostModify:kbl */
+        I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
+                   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
 }
 
 static void skylake_init_clock_gating(struct drm_device *dev)
 {
+        struct drm_i915_private *dev_priv = dev->dev_private;
+
         gen9_init_clock_gating(dev);
+
+        /* WaFbcNukeOnHostModify:skl */
+        I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
+                   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
 }
 
 static void broadwell_init_clock_gating(struct drm_device *dev)