2 files changed, 25 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 6abb15f13c2..5cfc68940f1 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -513,6 +513,10 @@
 #define   GEN6_BLITTER_SYNC_STATUS                      (1 << 24)
 #define   GEN6_BLITTER_USER_INTERRUPT                   (1 << 22)
 
+#define GEN6_BLITTER_ECOSKPD    0x221d0
+#define   GEN6_BLITTER_LOCK_SHIFT                       16
+#define   GEN6_BLITTER_FBC_NOTIFY                       (1<<3)
+
 #define GEN6_BSD_SLEEP_PSMI_CONTROL     0x12050
 #define   GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_MODIFY_MASK       (1 << 16)
 #define   GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_DISABLE           (1 << 0)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index d2ef1c2c65e..d7f237deaaf 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1213,6 +1213,26 @@ static bool g4x_fbc_enabled(struct drm_device *dev)
         return I915_READ(DPFC_CONTROL) & DPFC_CTL_EN;
 }
 
+static void sandybridge_blit_fbc_update(struct drm_device *dev)
+{
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        u32 blt_ecoskpd;
+
+        /* Make sure blitter notifies FBC of writes */
+        __gen6_force_wake_get(dev_priv);
+        blt_ecoskpd = I915_READ(GEN6_BLITTER_ECOSKPD);
+        blt_ecoskpd |= GEN6_BLITTER_FBC_NOTIFY <<
+                GEN6_BLITTER_LOCK_SHIFT;
+        I915_WRITE(GEN6_BLITTER_ECOSKPD, blt_ecoskpd);
+        blt_ecoskpd |= GEN6_BLITTER_FBC_NOTIFY;
+        I915_WRITE(GEN6_BLITTER_ECOSKPD, blt_ecoskpd);
+        blt_ecoskpd &= ~(GEN6_BLITTER_FBC_NOTIFY <<
+                         GEN6_BLITTER_LOCK_SHIFT);
+        I915_WRITE(GEN6_BLITTER_ECOSKPD, blt_ecoskpd);
+        POSTING_READ(GEN6_BLITTER_ECOSKPD);
+        __gen6_force_wake_put(dev_priv);
+}
+
 static void ironlake_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
 {
         struct drm_device *dev = crtc->dev;
@@ -1266,6 +1286,7 @@ static void ironlake_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
                 I915_WRITE(SNB_DPFC_CTL_SA,
                            SNB_CPU_FENCE_ENABLE | dev_priv->cfb_fence);
                 I915_WRITE(DPFC_CPU_FENCE_OFFSET, crtc->y);
+                sandybridge_blit_fbc_update(dev);
         }
 
         DRM_DEBUG_KMS("enabled fbc on plane %d\n", intel_crtc->plane);