Re: [PATCH AUTOSEL 5.5 188/542] tty: omap-serial: remove set but unused variable

[Greg Kroah-Hartman]

On Fri, Feb 14, 2020 at 10:43:00AM -0500, Sasha Levin wrote:
> From: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
> 
> [ Upstream commit e83c6587c47caa2278aa3bd603b5a85eddc4cec9 ]
> 
> Fix the following warning:
> drivers/tty/serial/omap-serial.c: In function serial_omap_rlsi:
> drivers/tty/serial/omap-serial.c:496:16: warning: variable ch set but not used [-Wunused-but-set-variable]
> 
> The character read is useless according to the table 23-246 of the omap4
> TRM. So we can drop it.
> 
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
> Link: https://lore.kernel.org/r/1575617863-32484-1-git-send-email-wangxiongfeng2@xxxxxxxxxx
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> ---
>  drivers/tty/serial/omap-serial.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
> index 6420ae581a802..5f808d8dfcd5c 100644
> --- a/drivers/tty/serial/omap-serial.c
> +++ b/drivers/tty/serial/omap-serial.c
> @@ -493,10 +493,13 @@ static unsigned int check_modem_status(struct uart_omap_port *up)
>  static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr)
>  {
>  	unsigned int flag;
> -	unsigned char ch = 0;
>  
> +	/*
> +	 * Read one data character out to avoid stalling the receiver according
> +	 * to the table 23-246 of the omap4 TRM.
> +	 */
>  	if (likely(lsr & UART_LSR_DR))
> -		ch = serial_in(up, UART_RX);
> +		serial_in(up, UART_RX);
>  
>  	up->port.icount.rx++;
>  	flag = TTY_NORMAL;
> -- 
> 2.20.1
>

Please drop.