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 cd0ffa015c27cda1fad42e21d2d21ed00a0956df..78f336e008365f26a5bc6a5df98614fe30cb3877 100644 (file)
--- 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 db4c38700951e787002943150b0e2b6230e8eab2..e189fd6dedcf9f373edd7167174a5eb8a0a416bc 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1515,7 +1515,7 @@ static void igdng_crtc_dpms(struct drm_crtc *crtc, int mode)
                /* 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);