From patchwork Mon May 11 11:00:31 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Nicolas Ferre X-Patchwork-Id: 470703 Return-Path: X-Original-To: incoming-imx@patchwork.ozlabs.org Delivered-To: patchwork-incoming-imx@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2001:1868:205::9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 7C5D7140157 for ; Mon, 11 May 2015 21:03:07 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YrlS8-0000SP-Ra; Mon, 11 May 2015 11:00:52 +0000 Received: from eusmtp01.atmel.com ([212.144.249.242]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YrlS5-0000Mf-L7 for linux-arm-kernel@lists.infradead.org; Mon, 11 May 2015 11:00:50 +0000 Received: from tenerife.corp.atmel.com (10.161.101.13) by eusmtp01.atmel.com (10.161.101.30) with Microsoft SMTP Server id 14.2.347.0; Mon, 11 May 2015 13:00:26 +0200 From: Nicolas Ferre To: , Subject: [PATCH] tty/serial: at91: RS485 mode: 0 is valid for delay_rts_after_send Date: Mon, 11 May 2015 13:00:31 +0200 Message-ID: <1431342044-23343-1-git-send-email-nicolas.ferre@atmel.com> X-Mailer: git-send-email 2.1.3 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150511_040050_052279_E231BA9C X-CRM114-Status: GOOD ( 10.91 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [212.144.249.242 listed in list.dnswl.org] -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record Cc: stable@vger.kernel.org, Sami.Pietikainen@wapice.com, Nicolas Ferre , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org List-Id: linux-imx-kernel.lists.patchwork.ozlabs.org In RS485 mode, we may want to set the delay_rts_after_send value to 0. In the datasheet, the 0 value is said to "disable" the Transmitter Timeguard but this is exactly the expected behavior if we want no delay... Moreover, if the value was set to non-zero value by device-tree or earlier ioctl command, it was impossible to change it back to zero. Reported-by: Sami Pietikäinen Signed-off-by: Nicolas Ferre Cc: stable@vger.kernel.org # 3.2+ --- drivers/tty/serial/atmel_serial.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 27dade29646b..5ca1dfb0561c 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -315,8 +315,7 @@ static int atmel_config_rs485(struct uart_port *port, if (rs485conf->flags & SER_RS485_ENABLED) { dev_dbg(port->dev, "Setting UART to RS485\n"); atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; - if ((rs485conf->delay_rts_after_send) > 0) - UART_PUT_TTGR(port, rs485conf->delay_rts_after_send); + UART_PUT_TTGR(port, rs485conf->delay_rts_after_send); mode |= ATMEL_US_USMODE_RS485; } else { dev_dbg(port->dev, "Setting UART to RS232\n"); @@ -354,8 +353,7 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) /* override mode to RS485 if needed, otherwise keep the current mode */ if (port->rs485.flags & SER_RS485_ENABLED) { - if ((port->rs485.delay_rts_after_send) > 0) - UART_PUT_TTGR(port, port->rs485.delay_rts_after_send); + UART_PUT_TTGR(port, port->rs485.delay_rts_after_send); mode &= ~ATMEL_US_USMODE; mode |= ATMEL_US_USMODE_RS485; } @@ -2061,8 +2059,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, /* mode */ if (port->rs485.flags & SER_RS485_ENABLED) { - if ((port->rs485.delay_rts_after_send) > 0) - UART_PUT_TTGR(port, port->rs485.delay_rts_after_send); + UART_PUT_TTGR(port, port->rs485.delay_rts_after_send); mode |= ATMEL_US_USMODE_RS485; } else if (termios->c_cflag & CRTSCTS) { /* RS232 with hardware handshake (RTS/CTS) */