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Date:   Sat, 25 Jun 2022 22:19:12 +0200
From:   Lukas Wunner <lukas@wunner.de>
To:     Ilpo =?iso-8859-1?Q?J=E4rvinen?= <ilpo.jarvinen@linux.intel.com>
Cc:     linux-serial@vger.kernel.org, Greg KH <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        linux-kernel@vger.kernel.org,
        Lino Sanfilippo <LinoSanfilippo@gmx.de>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: Re: [PATCH 01/36] serial: Add uart_rs485_config()
Message-ID: <20220625201912.GA29720@wunner.de>
References: <20220606100433.13793-1-ilpo.jarvinen@linux.intel.com>
 <20220606100433.13793-2-ilpo.jarvinen@linux.intel.com>
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On Mon, Jun 06, 2022 at 01:03:58PM +0300, Ilpo Järvinen wrote:
> A few serial drivers make a call to rs485_config() themselves (all
> these seem to relate to init). Convert them all to use a common helper
> which makes it easy to make adjustments on tasks related to it as
> serial_rs485 struct sanitization is going to be added.
[...]
 --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -1276,6 +1276,12 @@ static int uart_get_icount(struct tty_struct *tty,
>  	return 0;
>  }
>  
> +int uart_rs485_config(struct uart_port *port)
> +{
> +	return port->rs485_config(port, &port->rs485);
> +}
> +EXPORT_SYMBOL_GPL(uart_rs485_config);

Why doesn't this helper acquire the port spinlock, unlike
uart_set_rs485_config()?  Is this safe?  Do all callers hold the lock?
Do we need an assertion to verify the lock is held?

Thanks,

Lukas