drm/i915: fix panel fitting filter coefficient select for Ironlake
Must set filter selection as hardcoded coefficients for medium 3x3
filtering, which matches vbios setting for Ironlake.
This fixes display corrupt issue on HP arrandale with new vbios.
Cc: Stable Team <stable@kernel.org>
Signed-off-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 db4c387..e189fd6 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1515,7 +1515,7 @@
/* Enable panel fitting for LVDS */
if (intel_pipe_has_type(crtc, INTEL_OUTPUT_LVDS)) {
temp = I915_READ(pf_ctl_reg);
- I915_WRITE(pf_ctl_reg, temp | PF_ENABLE);
+ I915_WRITE(pf_ctl_reg, temp | PF_ENABLE | PF_FILTER_MED_3x3);
/* currently full aspect */
I915_WRITE(pf_win_pos, 0);