Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757065AbbGPCJk (ORCPT ); Wed, 15 Jul 2015 22:09:40 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:55420 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754332AbbGPBKS (ORCPT ); Wed, 15 Jul 2015 21:10:18 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Nicolas Ferre , Greg Kroah-Hartman , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 056/251] tty/serial: at91: RS485 mode: 0 is valid for delay_rts_after_send Date: Wed, 15 Jul 2015 18:06:17 -0700 Message-Id: <1437008972-9140-57-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1437008972-9140-1-git-send-email-kamal@canonical.com> References: <1437008972-9140-1-git-send-email-kamal@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2688 Lines: 66 3.19.8-ckt4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicolas Ferre commit 8687634b7908c42eb700e0469e110e02833611d1 upstream. 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 Signed-off-by: Greg Kroah-Hartman [ kamal: backport to 3.19-stable: context ] Signed-off-by: Kamal Mostafa --- 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 95f8f64..1ce085a 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -308,8 +308,7 @@ 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"); @@ -370,8 +369,7 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) if (port->rs485.flags & SER_RS485_ENABLED) { dev_dbg(port->dev, "Setting UART to RS485\n"); - 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 { dev_dbg(port->dev, "Setting UART to RS232\n"); @@ -2026,8 +2024,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, mode &= ~ATMEL_US_USMODE; 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; } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/