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UART: Fix spurious interrupts generated by ns8250 and lpc drivers:

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- don't enable transmitter empty interrupt before filling TX FIFO.
 - add missing uart_barrier() call in interrupt service routine
This commit is contained in:
Michal Meloun 2016-02-12 05:14:58 +00:00
parent 4b9a5d61f2
commit 3c7b90774d
2 changed files with 6 additions and 4 deletions
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5
sys/dev/uart/uart_dev_lpc.c
View File

@ -659,6 +659,7 @@ lpc_ns8250_bus_ipend(struct uart_softc *sc)
if (iir & IIR_TXRDY) {
ipend |= SER_INT_TXIDLE;
uart_setreg(bas, REG_IER, lpc_ns8250->ier);
uart_barrier(bas);
} else
ipend |= SER_INT_SIGCHG;
}
@ -892,12 +893,12 @@ lpc_ns8250_bus_transmit(struct uart_softc *sc)
uart_lock(sc->sc_hwmtx);
while ((uart_getreg(bas, REG_LSR) & LSR_THRE) == 0)
;
uart_setreg(bas, REG_IER, lpc_ns8250->ier | IER_ETXRDY);
uart_barrier(bas);
for (i = 0; i < sc->sc_txdatasz; i++) {
uart_setreg(bas, REG_DATA, sc->sc_txbuf[i]);
uart_barrier(bas);
}
uart_setreg(bas, REG_IER, lpc_ns8250->ier | IER_ETXRDY);
uart_barrier(bas);
sc->sc_txbusy = 1;
uart_unlock(sc->sc_hwmtx);
return (0);

5
sys/dev/uart/uart_dev_ns8250.c
View File

@ -708,6 +708,7 @@ ns8250_bus_ipend(struct uart_softc *sc)
if (iir & IIR_TXRDY) {
ipend |= SER_INT_TXIDLE;
uart_setreg(bas, REG_IER, ns8250->ier);
uart_barrier(bas);
} else
ipend |= SER_INT_SIGCHG;
}
@ -979,12 +980,12 @@ ns8250_bus_transmit(struct uart_softc *sc)
uart_lock(sc->sc_hwmtx);
while ((uart_getreg(bas, REG_LSR) & LSR_THRE) == 0)
;
uart_setreg(bas, REG_IER, ns8250->ier | IER_ETXRDY);
uart_barrier(bas);
for (i = 0; i < sc->sc_txdatasz; i++) {
uart_setreg(bas, REG_DATA, sc->sc_txbuf[i]);
uart_barrier(bas);
}
uart_setreg(bas, REG_IER, ns8250->ier | IER_ETXRDY);
uart_barrier(bas);
if (broken_txfifo)
ns8250_drain(bas, UART_DRAIN_TRANSMITTER);
else