From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753838AbdLGM6Z (ORCPT ); Thu, 7 Dec 2017 07:58:25 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:60158 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753701AbdLGM6V (ORCPT ); Thu, 7 Dec 2017 07:58:21 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ricardo Ribalda Delgado , "Ji-Ze Hong (Peter Hong)" , Lukas Wunner , Sasha Levin Subject: [PATCH 4.9 017/109] serial: 8250_fintek: Fix rs485 disablement on invalid ioctl() Date: Thu, 7 Dec 2017 13:56:01 +0100 Message-Id: <20171207125636.656322166@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171207125634.631485452@linuxfoundation.org> References: <20171207125634.631485452@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_fintek.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/tty/serial/8250/8250_fintek.c +++ b/drivers/tty/serial/8250/8250_fintek.c @@ -121,7 +121,7 @@ static int fintek_8250_rs485_config(stru 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;