drm/i915: Don't preserve DPFC_CONTROL bits ILK/SNB

On CTG and IVB+ we don't try to preserve any bits from the
DPFC_CONTROL register. Follow suit on ILK/SNB.

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>

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 75aceaaace8e259f95248a22d633c96a48b8fc00..cd031b6640fcdf874b2706d7e43dbd037993e67b 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -227,9 +227,7 @@ static void ironlake_enable_fbc(struct drm_crtc *crtc)
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        u32 dpfc_ctl;
 
-       dpfc_ctl = I915_READ(ILK_DPFC_CONTROL);
-       dpfc_ctl &= DPFC_RESERVED;
-       dpfc_ctl |= DPFC_CTL_PLANE(intel_crtc->plane);
+       dpfc_ctl = DPFC_CTL_PLANE(intel_crtc->plane);
        if (drm_format_plane_cpp(fb->pixel_format, 0) == 2)
                dpfc_ctl |= DPFC_CTL_LIMIT_2X;
        else