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 C0F51C433EF for ; Tue, 19 Jul 2022 13:12:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243445AbiGSNM2 (ORCPT ); Tue, 19 Jul 2022 09:12:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243381AbiGSNLa (ORCPT ); Tue, 19 Jul 2022 09:11:30 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E49F51A33; Tue, 19 Jul 2022 05:29:19 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 6FC3760693; Tue, 19 Jul 2022 12:29:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52A4DC341C6; Tue, 19 Jul 2022 12:29:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658233757; bh=nEJuKUP5wKVEzPwcC7gagL5tqUtbfcGdK91R5O8E0zM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2tVAyJweBsPFWPTFYXhMrst3CxsF5HhKAb3B7OYtITChrG1KEQM7hrT3gA5Zuf8dD Ph2ttowz5TWX6b+4GGKhX/cvcJQ8xHRZiEMiRlE/pg7JkKLxzUzla/kL29jhjHlHTA AOBV+4mEK7PC5MHd28nn0Ho0jVpB93N8ho/U+VA8= 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 5.18 230/231] serial: mvebu-uart: correctly report configured baudrate value Date: Tue, 19 Jul 2022 13:55:15 +0200 Message-Id: <20220719114732.969474264@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220719114714.247441733@linuxfoundation.org> References: <20220719114714.247441733@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: linux-kernel@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 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 @@ -470,14 +470,14 @@ 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; unsigned long flags; u32 brdv, osamp; if (!port->uartclk) - return -EOPNOTSUPP; + return 0; /* * The baudrate is derived from the UART clock thanks to divisors: @@ -548,7 +548,7 @@ static int mvebu_uart_baud_rate_set(stru (m_divisor << 16) | (m_divisor << 24); 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, @@ -587,15 +587,11 @@ static void mvebu_uart_set_termios(struc max_baud = port->uartclk / 80; 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) { @@ -606,6 +602,11 @@ 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); }