diff --git a/sys/dev/uart/uart_dev_ns8250.c b/sys/dev/uart/uart_dev_ns8250.c index d920a76ae275..45b4d315c3d5 100644 --- a/sys/dev/uart/uart_dev_ns8250.c +++ b/sys/dev/uart/uart_dev_ns8250.c @@ -738,6 +738,7 @@ ns8250_bus_ipend(struct uart_softc *sc) } else { if (iir & IIR_TXRDY) { ipend |= SER_INT_TXIDLE; + ns8250->ier &= ~IER_ETXRDY; uart_setreg(bas, REG_IER, ns8250->ier); uart_barrier(bas); } else @@ -1035,7 +1036,9 @@ ns8250_bus_transmit(struct uart_softc *sc) uart_setreg(bas, REG_DATA, sc->sc_txbuf[i]); uart_barrier(bas); } - uart_setreg(bas, REG_IER, ns8250->ier | IER_ETXRDY); + if (!broken_txfifo) + ns8250->ier |= IER_ETXRDY; + uart_setreg(bas, REG_IER, ns8250->ier); uart_barrier(bas); if (broken_txfifo) ns8250_drain(bas, UART_DRAIN_TRANSMITTER);