bif_path_cost
bif->bif_path_cost;
bif->bif_path_cost < sc->sc_root_port->bif_path_cost)
bif->bif_path_cost > sc->sc_root_port->bif_path_cost)
if (bif->bif_peer_cost + bif->bif_path_cost > designated_cost)
if (bif->bif_peer_cost + bif->bif_path_cost < designated_cost)
designated_cost = bif->bif_peer_cost + bif->bif_path_cost;
if (bif->bif_peer_cost + bif->bif_path_cost > designated_cost)
if (bif->bif_peer_cost + bif->bif_path_cost < designated_cost)
designated_cost = bif->bif_peer_cost + bif->bif_path_cost;
req->ifbr_path_cost = bif->bif_path_cost;
req->ifbr_designated_cost = bif->bif_path_cost +
bif->bif_path_cost = req->ifbr_path_cost;