On Fri, Jul 19, 2019 at 11:47:52AM +0300, Sergey Organov wrote:
> set_termios() shouldn't set UCR2_CTSC bit if UCR2_CTS (=TIOCM_RTS) is
> cleared. Added corresponding check in imx_uart_rts_auto() to fix this.
This is not understandable unless you read the reference manual.
In terms understandable without manual, this patch does:
Don't let the receiver hardware control the RTS output if it was
requested to be inactive.
> Reviewed-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Tested-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Signed-off-by: Sergey Organov <sorganov@xxxxxxxxx>
> ---
> drivers/tty/serial/imx.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index 57d6e6b..95d7984 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -405,7 +405,8 @@ static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
> /* called with port.lock taken and irqs caller dependent */
> static void imx_uart_rts_auto(struct imx_port *sport, u32 *ucr2)
> {
> - *ucr2 |= UCR2_CTSC;
> + if (*ucr2 & UCR2_CTS)
> + *ucr2 |= UCR2_CTSC;
I think this patch is wrong or the commit log is insufficient.
imx_uart_rts_auto() has only a single caller and there ucr2 & UCR2_CTS is
never true. And CTSC isn't restored anywhere, is it?
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
