drm/sun4i: DW HDMI: Release nodes if error happens during CRTC search

If error happens in sun8i_dw_hdmi_find_possible_crtcs(), nodes are not
released with of_node_put() before returning.

Fix that by calling of_node_put() when necessary. While on it, clean up
the code by using of_graph_get_remote_node() which also lowers number of
cases where error handling has to be performed.

Fixes: 57e23de0 ("drm/sun4i: DW HDMI: Expand algorithm for possible crtcs")
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180710203511.18454-8-jernej.skrabec@siol.net

drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c

@@ -53,22 +53,14 @@ static u32 sun8i_dw_hdmi_find_possible_crtcs(struct drm_device *drm,
 	struct device_node *port, *ep, *remote, *remote_port;
 	u32 crtcs = 0;
 
-	port = of_graph_get_port_by_id(node, 0);
-	if (!port)
-		return 0;
-
-	ep = of_get_next_available_child(port, NULL);
-	if (!ep)
-		return 0;
-
-	remote = of_graph_get_remote_port_parent(ep);
+	remote = of_graph_get_remote_node(node, 0, -1);
 	if (!remote)
 		return 0;
 
 	if (sun8i_dw_hdmi_node_is_tcon_top(remote)) {
 		port = of_graph_get_port_by_id(remote, 4);
 		if (!port)
-			return 0;
+			goto crtcs_exit;
 
 		for_each_child_of_node(port, ep) {
 			remote_port = of_graph_get_remote_port(ep);
@@ -81,6 +73,9 @@ static u32 sun8i_dw_hdmi_find_possible_crtcs(struct drm_device *drm,
 		crtcs = drm_of_find_possible_crtcs(drm, node);
 	}
 
+crtcs_exit:
+	of_node_put(remote);
+
 	return crtcs;
 }