From: Jiri Slaby <jirislaby@kernel.org>
To: Lino Sanfilippo <LinoSanfilippo@gmx.de>, gregkh@linuxfoundation.org
Cc: linux@armlinux.org.uk, richard.genoud@gmail.com,
nicolas.ferre@microchip.com, alexandre.belloni@bootlin.com,
ludovic.desroches@microchip.com, shawnguo@kernel.org,
s.hauer@pengutronix.de, kernel@pengutronix.de,
festevam@gmail.com, linux-imx@nxp.com, mcoquelin.stm32@gmail.com,
alexandre.torgue@foss.st.com, linux-serial@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-stm32@st-md-mailman.stormreply.com, lukas@wunner.de
Subject: Re: [PATCH 1/9] serial: core: move RS485 configuration tasks from drivers into core
Date: Mon, 14 Feb 2022 06:41:13 +0100 [thread overview]
Message-ID: <aa45fed9-7a40-7ac1-a000-18d2805d088f@kernel.org> (raw)
In-Reply-To: <20220213222737.15709-2-LinoSanfilippo@gmx.de>
On 13. 02. 22, 23:27, Lino Sanfilippo wrote:
> Several drivers that support setting the RS485 configuration via userspace
> implement on or more of the following tasks:
>
> - 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.
>
> Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
> ---
> 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);
Why is this magic 100? Can we have that number somehow documented? You
should define a macro for that anyway.
> + memset(rs485.padding, 0, sizeof(rs485.padding));
What is this memset good for?
> spin_lock_irqsave(&port->lock, flags);
> ret = port->rs485_config(port, &rs485);
> + if (!ret)
> + port->rs485 = rs485;
> spin_unlock_irqrestore(&port->lock, flags);
> if (ret)
> return ret;
thanks,
--
js
suse labs
next prev parent reply other threads:[~2022-02-14 5:41 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-13 22:27 Move RS485 implementation from drivers to serial core Lino Sanfilippo
2022-02-13 22:27 ` [PATCH 1/9] serial: core: move RS485 configuration tasks from drivers into core Lino Sanfilippo
2022-02-14 5:41 ` Jiri Slaby [this message]
2022-02-14 16:13 ` Lino Sanfilippo
2022-02-14 7:06 ` Uwe Kleine-König
2022-02-14 15:09 ` Lino Sanfilippo
2022-02-14 18:23 ` Uwe Kleine-König
2022-02-13 22:27 ` [PATCH 2/9] serial: amba-pl011: remove redundant code in rs485_config Lino Sanfilippo
2022-02-13 22:27 ` [PATCH 3/9] serial: stm32: " Lino Sanfilippo
2022-02-13 22:27 ` [PATCH 4/9] serial: sc16is7xx: " Lino Sanfilippo
2022-02-13 22:27 ` [PATCH 5/9] serial: omap: " Lino Sanfilippo
2022-02-13 22:27 ` [PATCH 6/9] serial: max310: " Lino Sanfilippo
2022-02-13 22:27 ` [PATCH 7/9] serial: imx: remove redundant assignment " Lino Sanfilippo
2022-02-13 22:27 ` [PATCH 8/9] serial: fsl_lpuart: remove redundant code in rs485_config functions Lino Sanfilippo
2022-02-13 22:27 ` [PATCH 9/9] serial: atmel: remove redundant assignment in rs485_config Lino Sanfilippo
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