From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753346AbdKVW2l (ORCPT ); Wed, 22 Nov 2017 17:28:41 -0500 Received: from omzsmtpe03.verizonbusiness.com ([199.249.25.208]:3676 "EHLO omzsmtpe03.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753205AbdKVW2T (ORCPT ); Wed, 22 Nov 2017 17:28:19 -0500 From: alexander.levin@verizon.com Cc: Lukas Wunner , Ricardo Ribalda Delgado , "Ji-Ze Hong (Peter Hong)" , Greg Kroah-Hartman , alexander.levin@verizon.com X-Host: mariner.tdc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH AUTOSEL for 4.9 06/24] serial: 8250_fintek: Fix rs485 disablement on invalid ioctl() Thread-Topic: [PATCH AUTOSEL for 4.9 06/24] serial: 8250_fintek: Fix rs485 disablement on invalid ioctl() Thread-Index: AQHTY+DmPApb548MZUewIZiU5E8+YQ== Date: Wed, 22 Nov 2017 22:26:11 +0000 Message-ID: <20171122222604.20122-6-alexander.levin@verizon.com> References: <20171122222604.20122-1-alexander.levin@verizon.com> In-Reply-To: <20171122222604.20122-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vAMMSiZF024108 From: Lukas Wunner [ Upstream commit 3236a965486ba0c6043cf2c7b51943d8b382ae29 ] This driver's ->rs485_config callback checks if SER_RS485_RTS_ON_SEND and SER_RS485_RTS_AFTER_SEND have the same value. If they do, it means the user has passed in invalid data with the TIOCSRS485 ioctl() since RTS must have a different polarity when sending and when not sending. In this case, rs485 mode is not enabled (the RS485_URA bit is not set in the RS485 Enable Register) and this is supposed to be signaled back to the user by clearing the SER_RS485_ENABLED bit in struct serial_rs485 ... except a missing tilde character is preventing that from happening. Fixes: 28e3fb6c4dce ("serial: Add support for Fintek F81216A LPC to 4 UART") Cc: Ricardo Ribalda Delgado Cc: "Ji-Ze Hong (Peter Hong)" Signed-off-by: Lukas Wunner Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/8250/8250_fintek.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c index 0facc789fe7d..9fc782642a36 100644 --- a/drivers/tty/serial/8250/8250_fintek.c +++ b/drivers/tty/serial/8250/8250_fintek.c @@ -118,7 +118,7 @@ static int fintek_8250_rs485_config(struct uart_port *port, if ((!!(rs485->flags & SER_RS485_RTS_ON_SEND)) == (!!(rs485->flags & SER_RS485_RTS_AFTER_SEND))) - rs485->flags &= SER_RS485_ENABLED; + rs485->flags &= ~SER_RS485_ENABLED; else config |= RS485_URA; -- 2.11.0