On Sun, Feb 13, 2022 at 11:27:29PM +0100, Lino Sanfilippo wrote:
> Several drivers that support setting the RS485 configuration via userspace
> implement on or more of the following tasks:
s/on/one/
>
> - in case of an invalid RTS configuration (both RTS after send and RTS on
> send set or both unset) fall back to enable RTS on send and disable RTS
> after send
>
> - nullify the padding field of the returned serial_rs485 struct
>
> - copy the configuration into the uart port struct
>
> - limit RTS delays to 100 ms
>
> Move these tasks into the serial core to make them generic and to provide
> a consistent beheviour among all drivers.
s/beheviour/behaviour/
> Signed-off-by: Lino Sanfilippo <LinoSanfilippo@xxxxxx>
> ---
> drivers/tty/serial/serial_core.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index 846192a7b4bf..3fab4070359c 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -1282,8 +1282,21 @@ static int uart_set_rs485_config(struct uart_port *port,
> if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
> return -EFAULT;
>
> + /* pick sane settings if the user hasn't */
> + if (!(rs485.flags & SER_RS485_RTS_ON_SEND) ==
> + !(rs485.flags & SER_RS485_RTS_AFTER_SEND)) {
> + rs485.flags |= SER_RS485_RTS_ON_SEND;
> + rs485.flags &= ~SER_RS485_RTS_AFTER_SEND;
> + }
> + /* clamp the delays to [0, 100ms] */
> + rs485.delay_rts_before_send = min(rs485.delay_rts_before_send, 100U);
> + rs485.delay_rts_after_send = min(rs485.delay_rts_after_send, 100U);
> + memset(rs485.padding, 0, sizeof(rs485.padding));
> +
> spin_lock_irqsave(&port->lock, flags);
> ret = port->rs485_config(port, &rs485);
> + if (!ret)
> + port->rs485 = rs485;
I was only Cc:d for the imx patch (patch #7) and tried to verify the
claim there that "the serial core already assigns the passed
configuration to the uart port". That failed when I looked at my kernel
tree.
So it would be great, if you sent dependencies (or at least a cover
letter) to all recipients of a given patch to ease review. Also I want
to suggest to mention uart_set_rs485_config() in the commit log of the
imx patch (and probably the others) to simplify verifying the claim
there.
Thanks
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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