Re: [PATCH v2] tty: serial: msm_serial: Fix XON/XOFF

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Mon 20 May 11:38 PDT 2019, Jorge Ramirez-Ortiz wrote:

> When the tty layer requests the uart to throttle, the current code
> executing in msm_serial will trigger "Bad mode in Error Handler" and
> generate an invalid stack frame in pstore before rebooting (that is if
> pstore is indeed configured: otherwise the user shall just notice a
> reboot with no further information dumped to the console).
> 
> This patch replaces the PIO byte accessor with the word accessor
> already used in PIO mode.
> 
> Fixes: 68252424a7c7 ("tty: serial: msm: Support big-endian CPUs")
> Cc: stable@vger.kernel.org
> Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

You missed Stephen's

Reviewed-by: Stephen Boyd <swboyd@chromium.org>

Regards,
Bjorn

> ---
>  drivers/tty/serial/msm_serial.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
> index 109096033bb1..23833ad952ba 100644
> --- a/drivers/tty/serial/msm_serial.c
> +++ b/drivers/tty/serial/msm_serial.c
> @@ -860,6 +860,7 @@ static void msm_handle_tx(struct uart_port *port)
>  	struct circ_buf *xmit = &msm_port->uart.state->xmit;
>  	struct msm_dma *dma = &msm_port->tx_dma;
>  	unsigned int pio_count, dma_count, dma_min;
> +	char buf[4] = { 0 };
>  	void __iomem *tf;
>  	int err = 0;
>  
> @@ -869,10 +870,12 @@ static void msm_handle_tx(struct uart_port *port)
>  		else
>  			tf = port->membase + UART_TF;
>  
> +		buf[0] = port->x_char;
> +
>  		if (msm_port->is_uartdm)
>  			msm_reset_dm_count(port, 1);
>  
> -		iowrite8_rep(tf, &port->x_char, 1);
> +		iowrite32_rep(tf, buf, 1);
>  		port->icount.tx++;
>  		port->x_char = 0;
>  		return;
> -- 
> 2.21.0
>