From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 508B0C25B06 for ; Wed, 27 Jul 2022 16:59:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236968AbiG0Q76 (ORCPT ); Wed, 27 Jul 2022 12:59:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241260AbiG0Q7V (ORCPT ); Wed, 27 Jul 2022 12:59:21 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4552067CAF; Wed, 27 Jul 2022 09:37:18 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 25840B821B6; Wed, 27 Jul 2022 16:37:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7AA25C433D6; Wed, 27 Jul 2022 16:37:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658939830; bh=hfbxyf/DUJ3IQqVUNeTv9mC8aZK0OZHI4xKyS0XTpjQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p7GEPPuyz47XWza4DJ1OjkR870T7yfBGuy/ClwfHjvxNMpe48bIP5wH+2svNcqKN5 /qXViuAYXNjwFmO95B/jrDJKgApeqJUoXTfI5kcLLq17RCtkA6NXkUPk5tTQfzmpA5 DCN1/eUpMdC+9g/zKWWGs65B19lcErHlJgI0pKNU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, stable , =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= , =?UTF-8?q?Pali=20Roh=C3=A1r?= Subject: [PATCH 5.15 014/201] serial: mvebu-uart: correctly report configured baudrate value Date: Wed, 27 Jul 2022 18:08:38 +0200 Message-Id: <20220727161027.512869711@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161026.977588183@linuxfoundation.org> References: <20220727161026.977588183@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Pali Rohár commit 4f532c1e25319e42996ec18a1f473fd50c8e575d upstream. Functions tty_termios_encode_baud_rate() and uart_update_timeout() should be called with the baudrate value which was set to hardware. Linux then report exact values via ioctl(TCGETS2) to userspace. Change mvebu_uart_baud_rate_set() function to return baudrate value which was set to hardware and propagate this value to above mentioned functions. With this change userspace would see precise value in termios c_ospeed field. Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate") Cc: stable Reviewed-by: Ilpo Järvinen Signed-off-by: Pali Rohár Link: https://lore.kernel.org/r/20220628100922.10717-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mvebu-uart.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) --- a/drivers/tty/serial/mvebu-uart.c +++ b/drivers/tty/serial/mvebu-uart.c @@ -442,13 +442,13 @@ static void mvebu_uart_shutdown(struct u } } -static int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud) +static unsigned int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud) { unsigned int d_divisor, m_divisor; u32 brdv, osamp; if (!port->uartclk) - return -EOPNOTSUPP; + return 0; /* * The baudrate is derived from the UART clock thanks to two divisors: @@ -472,7 +472,7 @@ static int mvebu_uart_baud_rate_set(stru osamp &= ~OSAMP_DIVISORS_MASK; writel(osamp, port->membase + UART_OSAMP); - return 0; + return DIV_ROUND_CLOSEST(port->uartclk, d_divisor * m_divisor); } static void mvebu_uart_set_termios(struct uart_port *port, @@ -509,15 +509,11 @@ static void mvebu_uart_set_termios(struc max_baud = 230400; baud = uart_get_baud_rate(port, termios, old, min_baud, max_baud); - if (mvebu_uart_baud_rate_set(port, baud)) { - /* No clock available, baudrate cannot be changed */ - if (old) - baud = uart_get_baud_rate(port, old, NULL, - min_baud, max_baud); - } else { - tty_termios_encode_baud_rate(termios, baud, baud); - uart_update_timeout(port, termios->c_cflag, baud); - } + baud = mvebu_uart_baud_rate_set(port, baud); + + /* In case baudrate cannot be changed, report previous old value */ + if (baud == 0 && old) + baud = tty_termios_baud_rate(old); /* Only the following flag changes are supported */ if (old) { @@ -528,6 +524,11 @@ static void mvebu_uart_set_termios(struc termios->c_cflag |= CS8; } + if (baud != 0) { + tty_termios_encode_baud_rate(termios, baud, baud); + uart_update_timeout(port, termios->c_cflag, baud); + } + spin_unlock_irqrestore(&port->lock, flags); }