linux-kernel - Re: [PATCH 1/2] serial: 8250_fintek: Return -EINVAL on invalid configuration

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Date:   Wed, 22 Nov 2017 23:30:39 +0100
From:   Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jslaby@...e.com>,
        "Ji-Ze Hong (Peter Hong)" <hpeter@...il.com>,
        Lukas Wunner <lukas@...ner.de>, linux-serial@...r.kernel.org,
        LKML <linux-kernel@...r.kernel.org>
Cc:     Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
Subject: Re: [PATCH 1/2] serial: 8250_fintek: Return -EINVAL on invalid configuration

ping?

On Mon, Nov 6, 2017 at 11:49 AM, Ricardo Ribalda Delgado
<ricardo.ribalda@...il.com> wrote:
> Hardware does not support having the same RTS level during RX and TX
> when RS485 mode is on (URA in Fintek terminology).
>
> The manufacturer has also confirmed that the delays are not enabled if
> the RS485 mode is not enabled.
>
> Therefore we should return -EINVAL if the user wants to have the same
> value for RTS_ON_SEND and RTS_AFTER_SEND.
>
> Cc: "Ji-Ze Hong (Peter Hong)" <hpeter@...il.com>
> Cc: Lukas Wunner <lukas@...ner.de>
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
> ---
>  drivers/tty/serial/8250/8250_fintek.c | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c
> index c41cbb52f1fe..ca7e96f9f080 100644
> --- a/drivers/tty/serial/8250/8250_fintek.c
> +++ b/drivers/tty/serial/8250/8250_fintek.c
> @@ -201,10 +201,17 @@ static int fintek_8250_rs485_config(struct uart_port *port,
>         if (!pdata)
>                 return -EINVAL;
>
> -       if (rs485->flags & SER_RS485_ENABLED)
> +       /* Hardware do not support same RTS level on send and receive */
> +       if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
> +                       !(rs485->flags & SER_RS485_RTS_AFTER_SEND))
> +               return -EINVAL;
> +
> +       if (rs485->flags & SER_RS485_ENABLED) {
>                 memset(rs485->padding, 0, sizeof(rs485->padding));
> -       else
> +               config |= RS485_URA;
> +       } else {
>                 memset(rs485, 0, sizeof(*rs485));
> +       }
>
>         rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
>                         SER_RS485_RTS_AFTER_SEND;
> @@ -219,12 +226,6 @@ static int fintek_8250_rs485_config(struct uart_port *port,
>                 config |= RXW4C_IRA;
>         }
>
> -       if ((!!(rs485->flags & SER_RS485_RTS_ON_SEND)) ==
> -                       (!!(rs485->flags & SER_RS485_RTS_AFTER_SEND)))
> -               rs485->flags &= ~SER_RS485_ENABLED;
> -       else
> -               config |= RS485_URA;
> -
>         if (rs485->flags & SER_RS485_RTS_ON_SEND)
>                 config |= RTS_INVERT;
>
> --
> 2.14.2
>



-- 
Ricardo Ribalda