diff options
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 6b1863293fe1..41b0dd67fcce 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1726,10 +1726,26 @@ static int pl011_allocate_irq(struct uart_amba_port *uap) */ static void pl011_enable_interrupts(struct uart_amba_port *uap) { + unsigned int i; + spin_lock_irq(&uap->port.lock); /* Clear out any spuriously appearing RX interrupts */ pl011_write(UART011_RTIS | UART011_RXIS, uap, REG_ICR); + + /* + * RXIS is asserted only when the RX FIFO transitions from below + * to above the trigger threshold. If the RX FIFO is already + * full to the threshold this can't happen and RXIS will now be + * stuck off. Drain the RX FIFO explicitly to fix this: + */ + for (i = 0; i < uap->fifosize * 2; ++i) { + if (pl011_read(uap, REG_FR) & UART01x_FR_RXFE) + break; + + pl011_read(uap, REG_DR); + } + uap->im = UART011_RTIM; if (!pl011_dma_rx_running(uap)) uap->im |= UART011_RXIM; |