From patchwork Mon Sep 15 14:00:08 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frans Klaver X-Patchwork-Id: 4905931 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 407A29F2EC for ; Mon, 15 Sep 2014 14:04:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2FB6920035 for ; Mon, 15 Sep 2014 14:07:33 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B8FD620274 for ; Mon, 15 Sep 2014 14:07:30 +0000 (UTC) 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 1XTWu6-0008UQ-Dy; Mon, 15 Sep 2014 14:05:18 +0000 Received: from filter1.ibarracuda.nl ([83.247.7.10]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XTWsU-00047w-Nc for linux-arm-kernel@lists.infradead.org; Mon, 15 Sep 2014 14:03:39 +0000 X-ASG-Debug-ID: 1410789668-0759e746c0323a0002-tbGyMd Received: from XSMCASSVR01.xsens-tech.local (rev-215.116.249.87.virtu.nl [87.249.116.215]) by filter1.ibarracuda.nl with ESMTP id HQCewHG4UTMAPxem (version=TLSv1 cipher=AES128-SHA bits=128 verify=NO); Mon, 15 Sep 2014 16:01:08 +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 (172.16.11.160) by XSMCASSVR01.xsens-tech.local (192.168.0.248) with Microsoft SMTP Server id 14.3.195.1; Mon, 15 Sep 2014 16:01:08 +0200 From: Frans Klaver To: Tony Lindgren Subject: [PATCH 2/4] tty: omap-serial: prevent division by zero Date: Mon, 15 Sep 2014 16:00:08 +0200 X-ASG-Orig-Subj: [PATCH 2/4] tty: omap-serial: prevent division by zero Message-ID: <1410789610-23059-3-git-send-email-frans.klaver@xsens.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1410789610-23059-1-git-send-email-frans.klaver@xsens.com> References: <1410789610-23059-1-git-send-email-frans.klaver@xsens.com> MIME-Version: 1.0 X-Originating-IP: [172.16.11.160] X-Barracuda-Connect: rev-215.116.249.87.virtu.nl[87.249.116.215] X-Barracuda-Start-Time: 1410789668 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 3.2.3.9505 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140915_070338_935305_E0F11EF5 X-CRM114-Status: UNSURE ( 9.79 ) X-CRM114-Notice: Please train this message. X-Spam-Score: 0.0 (/) Cc: Mark Rutland , Frans Klaver , Alexey Pelykh , Pawel Moll , Ian Campbell , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Felipe Balbi , devicetree@vger.kernel.org, Rob Herring , linux-serial@vger.kernel.org, Kumar Gala , linux-omap@vger.kernel.org, Jiri Slaby , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable 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..7d3f557 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 - (port->uartclk / (mode * n)); if (abs_diff < 0) abs_diff = -abs_diff;