TB_USB3_HOPID
path = tb_path_discover(down, TB_USB3_HOPID, NULL, -1,
path = tb_path_discover(tunnel->dst_port, -1, down, TB_USB3_HOPID, NULL,
path = tb_path_alloc(tb, down, TB_USB3_HOPID, up, TB_USB3_HOPID, 0,
path = tb_path_alloc(tb, up, TB_USB3_HOPID, down, TB_USB3_HOPID, 0,