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/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index cd0ffa0..78f336e 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2039,6 +2039,11 @@
#define PFA_CTL_1 0x68080
#define PFB_CTL_1 0x68880
#define PF_ENABLE (1<<31)
+#define PF_FILTER_MASK (3<<23)
+#define PF_FILTER_PROGRAMMED (0<<23)
+#define PF_FILTER_MED_3x3 (1<<23)
+#define PF_FILTER_EDGE_ENHANCE (2<<23)
+#define PF_FILTER_EDGE_SOFTEN (3<<23)
#define PFA_WIN_SZ 0x68074
#define PFB_WIN_SZ 0x68874
#define PFA_WIN_POS 0x68070
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);