drm/i915: Support 30 bit depth modes

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/i915/i915_reg.h

@@ -1915,6 +1915,7 @@
 #define   DISPPLANE_16BPP			(0x5<<26)
 #define   DISPPLANE_32BPP_NO_ALPHA		(0x6<<26)
 #define   DISPPLANE_32BPP			(0x7<<26)
+#define   DISPPLANE_32BPP_30BIT_NO_ALPHA	(0xa<<26)
 #define   DISPPLANE_STEREO_ENABLE		(1<<25)
 #define   DISPPLANE_STEREO_DISABLE		0
 #define   DISPPLANE_SEL_PIPE_MASK		(1<<24)

drivers/gpu/drm/i915/intel_display.c

@@ -1289,7 +1289,10 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y,
 		break;
 	case 24:
 	case 32:
-		dspcntr |= DISPPLANE_32BPP_NO_ALPHA;
+		if (crtc->fb->depth == 30)
+			dspcntr |= DISPPLANE_32BPP_30BIT_NO_ALPHA;
+		else
+			dspcntr |= DISPPLANE_32BPP_NO_ALPHA;
 		break;
 	default:
 		DRM_ERROR("Unknown color depth\n");