1 files changed, 10 insertions, 15 deletions

diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
index cb6609a56a03..fdc5e8e12ca8 100644
--- a/drivers/thunderbolt/tunnel.c
+++ b/drivers/thunderbolt/tunnel.c
@@ -2064,26 +2064,21 @@ struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,
 {
 	struct tb_tunnel *tunnel;
 	struct tb_path *path;
-	int max_rate = 0;
+	int max_rate;
 
-	/*
-	 * Check that we have enough bandwidth available for the new
-	 * USB3 tunnel.
-	 */
-	if (max_up > 0 || max_down > 0) {
+	if (!tb_route(down->sw) && (max_up > 0 || max_down > 0)) {
+		/*
+		 * For USB3 isochronous transfers, we allow bandwidth which is
+		 * not higher than 90% of maximum supported bandwidth by USB3
+		 * adapters.
+		 */
 		max_rate = tb_usb3_max_link_rate(down, up);
 		if (max_rate < 0)
 			return NULL;
 
-		/* Only 90% can be allocated for USB3 isochronous transfers */
 		max_rate = max_rate * 90 / 100;
-		tb_port_dbg(up, "required bandwidth for USB3 tunnel %d Mb/s\n",
+		tb_port_dbg(up, "maximum required bandwidth for USB3 tunnel %d Mb/s\n",
 			    max_rate);
-
-		if (max_rate > max_up || max_rate > max_down) {
-			tb_port_warn(up, "not enough bandwidth for USB3 tunnel\n");
-			return NULL;
-		}
 	}
 
 	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
@@ -2115,8 +2110,8 @@ struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,
 	tunnel->paths[TB_USB3_PATH_UP] = path;
 
 	if (!tb_route(down->sw)) {
-		tunnel->allocated_up = max_rate;
-		tunnel->allocated_down = max_rate;
+		tunnel->allocated_up = min(max_rate, max_up);
+		tunnel->allocated_down = min(max_rate, max_down);
 
 		tunnel->init = tb_usb3_init;
 		tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;