From: Jiri Slaby <jirislaby@kernel.org>
To: Lino Sanfilippo <LinoSanfilippo@gmx.de>,
Greg KH <gregkh@linuxfoundation.org>
Cc: linux@armlinux.org.uk, linux-serial@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] serial: amba-pl011: add RS485 support
Date: Fri, 25 Jun 2021 08:01:36 +0200 [thread overview]
Message-ID: <db436292-4115-0755-57d8-d63986f84453@kernel.org> (raw)
In-Reply-To: <5d7a4351-2adc-ea31-3290-91d91bd5a5d4@gmx.de>
On 25. 06. 21, 2:15, Lino Sanfilippo wrote:
>>> +static int pl011_rs485_config(struct uart_port *port,
>>> + struct serial_rs485 *rs485)
>>> +{
>>> + struct uart_amba_port *uap =
>>> + container_of(port, struct uart_amba_port, port);
>>> +
>>> + /* pick sane settings if the user hasn't */
>>> + if (!!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
>>
>> Why the !! in an if statement?
>>
>>> + !!(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
>>
>> Same here, why?
>>
>
> This was copied from serial8250_em485_config(). But I think we can simply use
>
> if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
> rs485->flags &= ~SER_RS485_RTS_ON_SEND;
> else
> rs485->flags |= SER_RS485_RTS_ON_SEND;
>
> instead. I will adjust the code accordingly.
This is different. You want to set ON_SEND when none is set. And unset
AFTER_SEND when both are set. In your code, when both are set, you leave
AFTER_SEND.
regards,
--
js
suse labs
next prev parent reply other threads:[~2021-06-25 6:01 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-18 14:51 [PATCH v2] serial: amba-pl011: add RS485 support Lino Sanfilippo
2021-06-24 12:55 ` Greg KH
2021-06-25 0:15 ` Lino Sanfilippo
2021-06-25 6:01 ` Jiri Slaby [this message]
2021-06-25 11:21 ` Lino Sanfilippo
2021-06-26 3:41 ` Jiri Slaby
2021-06-29 9:46 ` Lino Sanfilippo
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