We set up all the bits for DPFC_CONTROL but forgot to actually
write them to the register. Oops.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
        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));
 }