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 8D0A3C3F6B0 for ; Wed, 27 Jul 2022 16:38:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239152AbiG0QiV (ORCPT ); Wed, 27 Jul 2022 12:38:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238379AbiG0Qhg (ORCPT ); Wed, 27 Jul 2022 12:37:36 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D6F94F6B7; Wed, 27 Jul 2022 09:28:19 -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 ams.source.kernel.org (Postfix) with ESMTPS id 574AFB821A6; Wed, 27 Jul 2022 16:27:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEDE6C433D7; Wed, 27 Jul 2022 16:27:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658939269; bh=WtF9BKyztuDudarIy8lWa8uBbyXGJ5Wc6Q/lzCzgqR8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DS17Fi1yGp4eNpQEp0DI8T0qW6A9qwfw/9nXE6BOuKVyinBMQCI2EOrEXij93JFY9 Eds7+shP+wYuUALflsXQjzrVtR8NSCt8+MlCbamXDLZ12uB+YKfDCzw0k7jVvt4BEG QXtf+InspiSUTJ4V1bqxqfi/G12q9BWNIRcHLv2o= 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 5.4 10/87] serial: mvebu-uart: correctly report configured baudrate value Date: Wed, 27 Jul 2022 18:10:03 +0200 Message-Id: <20220727161009.434828786@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161008.993711844@linuxfoundation.org> References: <20220727161008.993711844@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 --- 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 @@ -443,13 +443,13 @@ 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: @@ -473,7 +473,7 @@ 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, @@ -510,15 +510,11 @@ 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) { @@ -529,6 +525,11 @@ 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); }