diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index a7af5b4d3eb47f1478958d73b387c76e324c7537..75aceaaace8e259f95248a22d633c96a48b8fc00 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -165,7 +165,7 @@ static void g4x_enable_fbc(struct drm_crtc *crtc)
 	I915_WRITE(DPFC_FENCE_YOFF, crtc->y);
 
 	/* enable it... */
-	I915_WRITE(DPFC_CONTROL, I915_READ(DPFC_CONTROL) | DPFC_CTL_EN);
+	I915_WRITE(DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
 
 	DRM_DEBUG_KMS("enabled fbc on plane %c\n", plane_name(intel_crtc->plane));
 }