From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A819A7E for ; Wed, 2 Nov 2022 03:19:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A79DDC433D6; Wed, 2 Nov 2022 03:19:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1667359190; bh=SR6wxlow1kMyqFdPSkHrArKVqnvetOh1gYLFtcs5nrs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0PBHY07McGYG0zm2Rv+r1sIHV1zfvEoiLY2pFHUle4vJIOJnWCKNydRTmmdq3rbgT sgRUuf2Xz+mbfWMYELNUWUYB+YRb88kpIRJh0WGgymhJy0D0PL13Ez2fGqM4eSG+64 Iemk5xetWvslJmix8nuHdh4KxShb3oUxpLDC87Q4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lino Sanfilippo , Daisuke Mizobuchi , Dominique Martinet Subject: [PATCH 5.10 90/91] serial: core: move RS485 configuration tasks from drivers into core Date: Wed, 2 Nov 2022 03:34:13 +0100 Message-Id: <20221102022057.605226414@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221102022055.039689234@linuxfoundation.org> References: <20221102022055.039689234@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Lino Sanfilippo commit 0ed12afa5655512ee418047fb3546d229df20aa1 upstream. Several drivers that support setting the RS485 configuration via userspace implement one 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 behaviour among all drivers. Signed-off-by: Lino Sanfilippo Link: https://lore.kernel.org/r/20220410104642.32195-2-LinoSanfilippo@gmx.de Signed-off-by: Daisuke Mizobuchi Signed-off-by: Dominique Martinet Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/serial_core.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -42,6 +42,11 @@ static struct lock_class_key port_lock_k #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8) +/* + * Max time with active RTS before/after data is sent. + */ +#define RS485_MAX_RTS_DELAY 100 /* msecs */ + static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, struct ktermios *old_termios); static void uart_wait_until_sent(struct tty_struct *tty, int timeout); @@ -1326,8 +1331,36 @@ static int uart_set_rs485_config(struct 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)) { + dev_warn_ratelimited(port->dev, + "%s (%d): invalid RTS setting, using RTS_ON_SEND instead\n", + port->name, port->line); + rs485.flags |= SER_RS485_RTS_ON_SEND; + rs485.flags &= ~SER_RS485_RTS_AFTER_SEND; + } + + if (rs485.delay_rts_before_send > RS485_MAX_RTS_DELAY) { + rs485.delay_rts_before_send = RS485_MAX_RTS_DELAY; + dev_warn_ratelimited(port->dev, + "%s (%d): RTS delay before sending clamped to %u ms\n", + port->name, port->line, rs485.delay_rts_before_send); + } + + if (rs485.delay_rts_after_send > RS485_MAX_RTS_DELAY) { + rs485.delay_rts_after_send = RS485_MAX_RTS_DELAY; + dev_warn_ratelimited(port->dev, + "%s (%d): RTS delay after sending clamped to %u ms\n", + port->name, port->line, rs485.delay_rts_after_send); + } + /* Return clean padding area to userspace */ + memset(rs485.padding, 0, sizeof(rs485.padding)); + 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;