diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 0643fa368d35..317bbc1dd2b4 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -799,7 +799,7 @@ out: static irqreturn_t lpuart_rxint(int irq, void *dev_id) { struct lpuart_port *sport = dev_id; - unsigned int flg, ignored = 0; + unsigned int flg, ignored = 0, overrun = 0; struct tty_port *port = &sport->port.state->port; unsigned long flags; unsigned char rx, sr; @@ -826,7 +826,7 @@ static irqreturn_t lpuart_rxint(int irq, void *dev_id) sport->port.icount.frame++; if (sr & UARTSR1_OR) - sport->port.icount.overrun++; + overrun++; if (sr & sport->port.ignore_status_mask) { if (++ignored > 100) @@ -853,6 +853,17 @@ static irqreturn_t lpuart_rxint(int irq, void *dev_id) } out: + if (overrun) { + sport->port.icount.overrun += overrun; + + /* + * Overruns cause FIFO pointers to become missaligned. + * Flushing the receive FIFO reinitializes the pointers. + */ + writeb(UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO); + writeb(UARTSFIFO_RXOF, sport->port.membase + UARTSFIFO); + } + spin_unlock_irqrestore(&sport->port.lock, flags); tty_flip_buffer_push(port);