TB_DP_AUX_TX_HOPID
path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX",
path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
TB_DP_AUX_TX_HOPID, link_nr, "AUX TX");