drm/i915: Enable aspect/centering panel fitting for Ironlake.

v2: Hook in DP paths to keep FULLSCREEN panel fitting on eDP.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 24fbd0f..25e3866 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2005,15 +2005,13 @@
 		/* Enable panel fitting for LVDS */
 		if (intel_pipe_has_type(crtc, INTEL_OUTPUT_LVDS)
 		    || HAS_eDP || intel_pch_has_edp(crtc)) {
-			temp = I915_READ(pf_ctl_reg);
-			I915_WRITE(pf_ctl_reg, temp | PF_ENABLE | PF_FILTER_MED_3x3);
-
-			/* currently full aspect */
-			I915_WRITE(pf_win_pos, 0);
-
-			I915_WRITE(pf_win_size,
-				   (dev_priv->panel_fixed_mode->hdisplay << 16) |
-				   (dev_priv->panel_fixed_mode->vdisplay));
+			if (dev_priv->pch_pf_size) {
+				temp = I915_READ(pf_ctl_reg);
+				I915_WRITE(pf_ctl_reg, temp | PF_ENABLE | PF_FILTER_MED_3x3);
+				I915_WRITE(pf_win_pos, dev_priv->pch_pf_pos);
+				I915_WRITE(pf_win_size, dev_priv->pch_pf_size);
+			} else
+				I915_WRITE(pf_ctl_reg, temp & ~PF_ENABLE);
 		}
 
 		/* Enable CPU pipe */