Re: [PATCH] serial: tegra: Correct error handling sequence

From: Greg KH
Date: Fri Apr 15 2022 - 02:41:39 EST


On Thu, Mar 24, 2022 at 02:34:04PM +0530, Kartik wrote:
> From: kartik <kkartik@xxxxxxxxxx>
>
> In the current error handling sequence the driver checks for break
> error at the end.
>
> By handling the break error first, we can avoid a situation where the
> driver keeps processing the errors which can be caused by an unhandled
> break error.
>
> Signed-off-by: kartik <kkartik@xxxxxxxxxx>

I need a full, legal name that you use to sign documents with. Is that
this name?

> ---
> drivers/tty/serial/serial-tegra.c | 26 +++++++++++++-------------
> 1 file changed, 13 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
> index b6223fa..ba78a02 100644
> --- a/drivers/tty/serial/serial-tegra.c
> +++ b/drivers/tty/serial/serial-tegra.c
> @@ -440,7 +440,19 @@ static char tegra_uart_decode_rx_error(struct tegra_uart_port *tup,
> char flag = TTY_NORMAL;
>
> if (unlikely(lsr & TEGRA_UART_LSR_ANY)) {
> - if (lsr & UART_LSR_OE) {
> + if (lsr & UART_LSR_BI) {
> + /*
> + * Break error
> + * If FIFO read error without any data, reset Rx FIFO
> + */
> + if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE))
> + tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_RCVR);
> + if (tup->uport.ignore_status_mask & UART_LSR_BI)
> + return TTY_BREAK;
> + flag = TTY_BREAK;
> + tup->uport.icount.brk++;
> + dev_dbg(tup->uport.dev, "Got Break\n");
> + } else if (lsr & UART_LSR_OE) {
> /* Overrrun error */
> flag = TTY_OVERRUN;
> tup->uport.icount.overrun++;
> @@ -454,18 +466,6 @@ static char tegra_uart_decode_rx_error(struct tegra_uart_port *tup,
> flag = TTY_FRAME;
> tup->uport.icount.frame++;
> dev_dbg(tup->uport.dev, "Got frame errors\n");
> - } else if (lsr & UART_LSR_BI) {
> - /*
> - * Break error
> - * If FIFO read error without any data, reset Rx FIFO
> - */
> - if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE))
> - tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_RCVR);
> - if (tup->uport.ignore_status_mask & UART_LSR_BI)
> - return TTY_BREAK;
> - flag = TTY_BREAK;
> - tup->uport.icount.brk++;
> - dev_dbg(tup->uport.dev, "Got Break\n");
> }
> uart_insert_char(&tup->uport, lsr, UART_LSR_OE, 0, flag);
> }

What commit does this fix?

thanks,

greg k-h