diff options
| -rw-r--r-- | sys/dev/uart/uart_dev_pl011.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/sys/dev/uart/uart_dev_pl011.c b/sys/dev/uart/uart_dev_pl011.c index 1d17286..e8e23d5 100644 --- a/sys/dev/uart/uart_dev_pl011.c +++ b/sys/dev/uart/uart_dev_pl011.c @@ -452,15 +452,23 @@ uart_pl011_bus_transmit(struct uart_softc *sc) __uart_setreg(bas, UART_DR, sc->sc_txbuf[i]); uart_barrier(bas); } - sc->sc_txbusy = 1; - /* Enable TX interrupt */ - reg = __uart_getreg(bas, UART_IMSC); - reg |= (UART_TXEMPTY); - __uart_setreg(bas, UART_IMSC, reg); + /* If not empty wait until it is */ + if ((__uart_getreg(bas, UART_FR) & FR_TXFE) != FR_TXFE) { + sc->sc_txbusy = 1; + + /* Enable TX interrupt */ + reg = __uart_getreg(bas, UART_IMSC); + reg |= (UART_TXEMPTY); + __uart_setreg(bas, UART_IMSC, reg); + } uart_unlock(sc->sc_hwmtx); + /* No interrupt expected, schedule the next fifo write */ + if (!sc->sc_txbusy) + uart_sched_softih(sc, SER_INT_TXIDLE); + return (0); } |
