OMAPDSS: check the return value of dss_mgr_enable()

Now that dss_mgr_enable returns an error value, check it in all the
places dss_mgr_enable is used, and bail out properly.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dsi.c b/drivers/video/omap2/dss/dsi.c
index 9cb2e82..4dc98b6 100644
--- a/drivers/video/omap2/dss/dsi.c
+++ b/drivers/video/omap2/dss/dsi.c
@@ -3979,6 +3979,7 @@
 	int bpp = dsi_get_pixel_size(dssdev->panel.dsi_pix_fmt);
 	u8 data_type;
 	u16 word_count;
+	int r;
 
 	if (dssdev->panel.dsi_mode == OMAP_DSS_DSI_VIDEO_MODE) {
 		switch (dssdev->panel.dsi_pix_fmt) {
@@ -4013,7 +4014,15 @@
 		dsi_if_enable(dsidev, true);
 	}
 
-	dss_mgr_enable(dssdev->manager);
+	r = dss_mgr_enable(dssdev->manager);
+	if (r) {
+		if (dssdev->panel.dsi_mode == OMAP_DSS_DSI_VIDEO_MODE) {
+			dsi_if_enable(dsidev, false);
+			dsi_vc_enable(dsidev, channel, false);
+		}
+
+		return r;
+	}
 
 	return 0;
 }