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 X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1ECFC3A5A7 for ; Wed, 4 Sep 2019 12:54:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A06182073F for ; Wed, 4 Sep 2019 12:54:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730177AbfIDMy5 (ORCPT ); Wed, 4 Sep 2019 08:54:57 -0400 Received: from wp498.webpack.hosteurope.de ([80.237.130.20]:46840 "EHLO wp498.webpack.hosteurope.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725965AbfIDMy4 (ORCPT ); Wed, 4 Sep 2019 08:54:56 -0400 X-Greylist: delayed 2250 seconds by postgrey-1.27 at vger.kernel.org; Wed, 04 Sep 2019 08:54:56 EDT Received: from p50937f79.dip0.t-ipconnect.de ([80.147.127.121] helo=ubuntu-VirtualBox.i.sigma-surface-science.com); authenticated by wp498.webpack.hosteurope.de running ExIM with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_CBC_SHA1:128) id 1i5UEh-0001JK-N9; Wed, 04 Sep 2019 14:18:07 +0200 From: =?UTF-8?q?Christoph=20Vogtl=C3=A4nder?= Cc: =?UTF-8?q?Christoph=20Vogtl=C3=A4nder?= , Greg Kroah-Hartman , Jiri Slaby , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] serial: max310x: turn off transmitter before activating AutoCTS or auto transmitter flow control Date: Wed, 4 Sep 2019 14:17:46 +0200 Message-Id: <20190904121746.4641-1-c.vogtlaender@sigma-surface-science.com> X-Mailer: git-send-email 2.22.1 In-Reply-To: <20190904073022.GB9729@kroah.com> References: <20190904073022.GB9729@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-bounce-key: webpack.hosteurope.de;c.vogtlaender@sigma-surface-science.com;1567601696;333f7ae9; X-HE-SMSGID: 1i5UEh-0001JK-N9 To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As documented in the data-sheet, the transmitter must be disabled before activating AutoCTS or auto transmitter flow control. Accordingly, the transmitter must be enabled after AutoCTS or auto transmitter flow control gets deactivated. Signed-off-by: Christoph VogtlÃĪnder --- drivers/tty/serial/max310x.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c index fb5a7e0e58e9..adfef6dae4a7 100644 --- a/drivers/tty/serial/max310x.c +++ b/drivers/tty/serial/max310x.c @@ -860,6 +860,15 @@ static void max310x_set_termios(struct uart_port *port, max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]); max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]); + /* Disable transmitter before enabling AutoCTS or auto transmitter + * flow control + */ + if (termios->c_cflag & CRTSCTS || termios->c_iflag & IXOFF) { + max310x_port_update(port, MAX310X_MODE1_REG, + MAX310X_MODE1_TXDIS_BIT, + MAX310X_MODE1_TXDIS_BIT); + } + port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF); if (termios->c_cflag & CRTSCTS) { @@ -878,6 +887,15 @@ static void max310x_set_termios(struct uart_port *port, } max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow); + /* Enable transmitter after disabling AutoCTS and auto transmitter + * flow control + */ + if (!(termios->c_cflag & CRTSCTS) && !(termios->c_iflag & IXOFF)) { + max310x_port_update(port, MAX310X_MODE1_REG, + MAX310X_MODE1_TXDIS_BIT, + 0); + } + /* Get baud rate generator configuration */ baud = uart_get_baud_rate(port, termios, old, port->uartclk / 16 / 0xffff, -- 2.22.1