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 CC8B0C433EF for ; Tue, 28 Jun 2022 10:23:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243816AbiF1KXn (ORCPT ); Tue, 28 Jun 2022 06:23:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239377AbiF1KXk (ORCPT ); Tue, 28 Jun 2022 06:23:40 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C3112FFC4; Tue, 28 Jun 2022 03:23:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1656411819; x=1687947819; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=wRjPbVKWB0JV41bfLywdOItEg7b3njNAAl1ELy2fXAI=; b=Gf7tnnPZc8e2pQpRQezdDGgNWN2joVeTpG9jCltYG7hOdcEso13SjfbJ rkMLJ0UOeU2OJakVLtcD8WGdx/UuHh3JeRDvxlv5R2PnO3Al2mbPI7YKI q/0VnEBM5Ad1ilbOcjd75iaRIsJA/n37MbzlEUHRZkqgToFTSmPIZ8RTt 2xixhTsuHeJ0cP9kgIOV7cESRD+cWNZPrwsDcfgklY3WX5hmGbLpfiHM5 c1Ye+E5wAh8oHdbFJofgnary0Yy50m5o5cGIcmmJiFoBXz4KVP4Y+siMN nu4Cl1hsF7JMRB/hp5CJbXcxNVd9G1XUfloNAXRuKfBxC3UEgOI+joNRR w==; X-IronPort-AV: E=McAfee;i="6400,9594,10391"; a="280462650" X-IronPort-AV: E=Sophos;i="5.92,227,1650956400"; d="scan'208";a="280462650" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jun 2022 03:23:39 -0700 X-IronPort-AV: E=Sophos;i="5.92,227,1650956400"; d="scan'208";a="646855987" Received: from iannetti-mobl.ger.corp.intel.com ([10.251.216.215]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jun 2022 03:23:37 -0700 Date: Tue, 28 Jun 2022 13:23:34 +0300 (EEST) From: =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= To: =?ISO-8859-15?Q?Pali_Roh=E1r?= cc: Greg Kroah-Hartman , Jiri Slaby , Allen Yan , Miquel Raynal , Gregory CLEMENT , linux-serial , LKML Subject: Re: [PATCH] serial: mvebu-uart: correctly report configured baudrate value In-Reply-To: <20220628100922.10717-1-pali@kernel.org> Message-ID: References: <20220628100922.10717-1-pali@kernel.org> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323329-888930425-1656411819=:1603" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-888930425-1656411819=:1603 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT On Tue, 28 Jun 2022, Pali Rohár wrote: > 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") Look better than my patch covering cases I didn't even realize existed. Thanks. Reviewed-by: Ilpo Järvinen -- i. > --- > 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); > } > > --8323329-888930425-1656411819=:1603--