From patchwork Tue Aug 19 12:14:46 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frans Klaver X-Patchwork-Id: 4742381 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id E99F4C0338 for ; Tue, 19 Aug 2014 12:18:05 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 753E020136 for ; Tue, 19 Aug 2014 12:18:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF18820172 for ; Tue, 19 Aug 2014 12:18:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753136AbaHSMQv (ORCPT ); Tue, 19 Aug 2014 08:16:51 -0400 Received: from filter1.ibarracuda.nl ([83.247.7.10]:51115 "EHLO filter1.ibarracuda.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751843AbaHSMO7 (ORCPT ); Tue, 19 Aug 2014 08:14:59 -0400 X-ASG-Debug-ID: 1408450496-0759e7416b47640e0002-g9IbbW Received: from XSMCASSVR01.xsens-tech.local (rev-215.116.249.87.virtu.nl [87.249.116.215]) by filter1.ibarracuda.nl with ESMTP id MHzxe6ub2qIWREHa (version=TLSv1 cipher=AES128-SHA bits=128 verify=NO); Tue, 19 Aug 2014 14:14:56 +0200 (CEST) X-Barracuda-Envelope-From: Frans.Klaver@xsens.com X-Barracuda-AUTH-User: xsenscom X-Barracuda-Apparent-Source-IP: 87.249.116.215 Received: from ci00147.xsens-tech.local (172.16.11.49) by XSMCASSVR01.xsens-tech.local (192.168.0.248) with Microsoft SMTP Server id 14.3.195.1; Tue, 19 Aug 2014 14:14:56 +0200 From: Frans Klaver To: Felipe Balbi CC: Frans Klaver , Tony Lindgren , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Greg Kroah-Hartman , Alexey Pelykh , Jiri Slaby , Frans Klaver , , , , , Subject: [PATCH 2/4] tty: omap-serial: prevent division by zero Date: Tue, 19 Aug 2014 14:14:46 +0200 X-ASG-Orig-Subj: [PATCH 2/4] tty: omap-serial: prevent division by zero Message-ID: <1408450488-4083-3-git-send-email-frans.klaver@xsens.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1408450488-4083-1-git-send-email-frans.klaver@xsens.com> References: <1406645577-18620-1-git-send-email-frans.klaver@xsens.com> <1408450488-4083-1-git-send-email-frans.klaver@xsens.com> MIME-Version: 1.0 X-Originating-IP: [172.16.11.49] X-Barracuda-Connect: rev-215.116.249.87.virtu.nl[87.249.116.215] X-Barracuda-Start-Time: 1408450496 X-Barracuda-Encrypted: AES128-SHA X-Barracuda-URL: http://filter1.ibarracuda.nl:8000/cgi-mod/mark.cgi X-Virus-Scanned: by bsmtpd at ibarracuda.nl X-Barracuda-BRTS-Status: 1 X-Barracuda-Spam-Score: 0.00 X-Barracuda-Spam-Status: No, SCORE=0.00 using per-user scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=5.0 tests= X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.3.8612 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If the chosen baud rate is large enough (e.g. 3.5 megabaud), the calculated n values in calculate_baud_abs_diff may become 0. This causes a division by zero when calculating the difference between calculated and desired baud rates. To prevent this, cap n on 1. Signed-off-by: Frans Klaver --- drivers/tty/serial/omap-serial.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index ae935ce..14a0167 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -246,8 +246,12 @@ static inline int calculate_baud_abs_diff(struct uart_port *port, unsigned int baud, unsigned int mode) { unsigned int n = port->uartclk / (mode * baud); - int abs_diff = baud - (port->uartclk / (mode * n)); + int abs_diff; + if (n == 0) + n = 1; + + abs_diff = baud - (uartclk / (mode * n)); if (abs_diff < 0) abs_diff = -abs_diff;