FIFO_TRIGGER_4
sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_4;
t->c_ospeed <= 38400 ? FIFO_TRIGGER_8 : FIFO_TRIGGER_4);
t->c_ospeed <= 38400 ? FIFO_TRIGGER_8 : FIFO_TRIGGER_4);
sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_4;
FIFO_TRIGGER_4 | FIFO_TRIGGER_8 | FIFO_TRIGGER_14);