TWA_CMD_AEN
if ((tr = twa_get_request(sc, TWA_CMD_AEN)) == NULL) {
KASSERT((flags & TWA_CMD_AEN) == 0);
if (__predict_false((flags & TWA_CMD_AEN) != 0)) {
if ((tr->tr_flags & TWA_CMD_AEN) == 0) {
if ((tr->tr_flags & TWA_CMD_AEN) != 0)
tr->tr_flags |= TWA_CMD_AEN;