drm/i915: Do not clobber the contents of TRANS_DP_CTL when enabling.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
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 281db6e..97a35a4 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2928,6 +2928,7 @@
#define TRANS_DP_VSYNC_ACTIVE_LOW 0
#define TRANS_DP_HSYNC_ACTIVE_HIGH (1<<3)
#define TRANS_DP_HSYNC_ACTIVE_LOW 0
+#define TRANS_DP_SYNC_MASK (3<<3)
/* SNB eDP training params */
/* SNB A-stepping */