FIFO_TRIGGER_8
sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
t->c_ospeed <= 38400 ? FIFO_TRIGGER_8 : FIFO_TRIGGER_4);
fifo |= FIFO_TRIGGER_8;
fifo |= FIFO_TRIGGER_8;
(t->c_ispeed <= 1200 ? FIFO_TRIGGER_1 : FIFO_TRIGGER_8));
(t->c_ispeed <= 1200 ? FIFO_TRIGGER_1 : FIFO_TRIGGER_8));