OMAPDSS: DISPC: Don't set chroma resampling bit for writeback

The bit YUVCHROMARESAMPLING isn't there for writeback in DISPC_WB_ATTRIBUTES2.
It isn't there because we don't upsample chroma like for video pipelines, we
downsample chroma in writeback to get YUV422 or NV12 formats from the YUV444
input.

Ignore this bit in dispc_ovl_set_scaling_uv() if the plane is OMAP_DSS_WB.
Signed-off-by: Archit Taneja <archit@ti.com>

drivers/video/omap2/dss/dispc.c

@@ -1468,7 +1468,8 @@ static void dispc_ovl_set_scaling_uv(enum omap_plane plane,
 			color_mode != OMAP_DSS_COLOR_UYVY &&
 			color_mode != OMAP_DSS_COLOR_NV12)) {
 		/* reset chroma resampling for RGB formats  */
-		REG_FLD_MOD(DISPC_OVL_ATTRIBUTES2(plane), 0, 8, 8);
+		if (plane != OMAP_DSS_WB)
+			REG_FLD_MOD(DISPC_OVL_ATTRIBUTES2(plane), 0, 8, 8);
 		return;
 	}
 
@@ -1520,8 +1521,10 @@ static void dispc_ovl_set_scaling_uv(enum omap_plane plane,
 			out_width, out_height, five_taps,
 				rotation, DISPC_COLOR_COMPONENT_UV);
 
-	REG_FLD_MOD(DISPC_OVL_ATTRIBUTES2(plane),
-		(scale_x || scale_y) ? 1 : 0, 8, 8);
+	if (plane != OMAP_DSS_WB)
+		REG_FLD_MOD(DISPC_OVL_ATTRIBUTES2(plane),
+			(scale_x || scale_y) ? 1 : 0, 8, 8);
+
 	/* set H scaling */
 	REG_FLD_MOD(DISPC_OVL_ATTRIBUTES(plane), scale_x ? 1 : 0, 5, 5);
 	/* set V scaling */