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 7D76CC43334 for ; Tue, 28 Jun 2022 10:09:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344724AbiF1KJv (ORCPT ); Tue, 28 Jun 2022 06:09:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344742AbiF1KJu (ORCPT ); Tue, 28 Jun 2022 06:09:50 -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 2FD542F666; Tue, 28 Jun 2022 03:09:49 -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 D28ACB81D93; Tue, 28 Jun 2022 10:09:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 50878C3411D; Tue, 28 Jun 2022 10:09:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1656410986; bh=2kqaknsisyJeDGY+X+iXUz3e7OQebOSh2VPWs+t5KCg=; h=From:To:Cc:Subject:Date:From; b=q1iUDDhb4Thtudo3GzAwdrBX82kGmMRcje8fr/uXlbXAFdRnPNpKwhaAPQTN48ldn DyYyBVMqYtYsOhc8Mv6OGUCgEVB53zlNXTuk4ASoWTpN9k1CkhCs3bPwYSov+WosdU m5ZYQ33St0tkBwQZAXzqgVOiBBUUavpizv+AGDGIWvr6RmcpPWmtniqRh0KNqw8Yb6 uBYzsw1KCOvX5Di4rUvkznt7Y0KoMCFmTBrBAzkt6VzkTyfUCOTvQ0FEpEj5oYOKhW UKhBXtsUGs0YhZyA2NrnTkIGQY6Ct5ofQj5YuiM5/B+wDkNH/zEOzzDfLSeGNHovR3 bZxgAP1IuNIVA== Received: by pali.im (Postfix) id 69C6D7AE; Tue, 28 Jun 2022 12:09:43 +0200 (CEST) From: =?UTF-8?q?Pali=20Roh=C3=A1r?= To: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= , Greg Kroah-Hartman , Jiri Slaby , Allen Yan , Miquel Raynal , Gregory CLEMENT Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] serial: mvebu-uart: correctly report configured baudrate value Date: Tue, 28 Jun 2022 12:09:22 +0200 Message-Id: <20220628100922.10717-1-pali@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org 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. Signed-off-by: Pali Rohár Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate") --- drivers/tty/serial/mvebu-uart.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c index 0429c2a54290..93489fe334d0 100644 --- a/drivers/tty/serial/mvebu-uart.c +++ b/drivers/tty/serial/mvebu-uart.c @@ -470,14 +470,14 @@ static void mvebu_uart_shutdown(struct uart_port *port) } } -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(struct uart_port *port, unsigned int baud) (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(struct uart_port *port, 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(struct uart_port *port, 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); } -- 2.20.1