drm/i915: Fix FDI M/N setting according with correct color depth
FDI M/N calculation hasn't taken the current pipe color depth into account,
but always set as 24bpp. This one checks current pipe color depth setting,
and change FDI M/N calculation a little to use bits_per_pixel first, then
convert to bytes_per_pixel later.
This fixes display corrupt issue on Arrandle LVDS with 1600x900 panel
in 18bpp dual-channel mode.
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 5f92724..0dd87a7 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1782,6 +1782,11 @@
#define PIPE_START_VBLANK_INTERRUPT_STATUS (1UL<<2) /* 965 or later */
#define PIPE_VBLANK_INTERRUPT_STATUS (1UL<<1)
#define PIPE_OVERLAY_UPDATED_STATUS (1UL<<0)
+#define PIPE_BPC_MASK (7 << 5) /* Ironlake */
+#define PIPE_8BPC (0 << 5)
+#define PIPE_10BPC (1 << 5)
+#define PIPE_6BPC (2 << 5)
+#define PIPE_12BPC (3 << 5)
#define DSPARB 0x70030
#define DSPARB_CSTART_MASK (0x7f << 7)