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

2 files changed, 9 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index da88444cecc5..312f254f62ae 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2209,6 +2209,7 @@ 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 8df9b5288679..1464d7ba69d4 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -6998,6 +6998,10 @@ 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)
@@ -7009,6 +7013,10 @@ static void skylake_init_clock_gating(struct drm_device *dev)
         /* WAC6entrylatency:skl */
         I915_WRITE(FBC_LLC_READ_CTRL, I915_READ(FBC_LLC_READ_CTRL) |
                    FBC_LLC_FULLY_OPEN);
+
+        /* 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)