linux-kernel - Re: [PATCH] serial: tegra: Correct error handling sequence

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Date:   Fri, 15 Apr 2022 08:41:27 +0200
From:   Greg KH <gregkh@...uxfoundation.org>
To:     Kartik <kkartik@...dia.com>
Cc:     ldewangan@...dia.com, jirislaby@...nel.org,
        thierry.reding@...il.com, jonathanh@...dia.com,
        linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org,
        linux-tegra@...r.kernel.org
Subject: Re: [PATCH] serial: tegra: Correct error handling sequence

On Thu, Mar 24, 2022 at 02:34:04PM +0530, Kartik wrote:
> From: kartik <kkartik@...dia.com>
> 
> 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@...dia.com>

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