From patchwork Tue Dec 1 22:55:40 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Wahren X-Patchwork-Id: 7741221 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 5BB05BEEE1 for ; Tue, 1 Dec 2015 22:58:04 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8D8202065B for ; Tue, 1 Dec 2015 22:58:03 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B1C7F2063B for ; Tue, 1 Dec 2015 22:58:02 +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 1a3tqk-0004QL-0z; Tue, 01 Dec 2015 22:56:42 +0000 Received: from mout.kundenserver.de ([212.227.17.10]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1a3tqg-0004Iv-7p; Tue, 01 Dec 2015 22:56:39 +0000 Received: from localhost.localdomain ([95.91.39.67]) by mrelayeu.kundenserver.de (mreue102) with ESMTPSA (Nemesis) id 0MGzR4-1a7jbV3XBS-00DoCR; Tue, 01 Dec 2015 23:56:04 +0100 From: Stefan Wahren To: Thierry Reding , Stephen Warren , Lee Jones , Eric Anholt Subject: [PATCH 2/3] pwm: bcm2835: prevent division by zero Date: Tue, 1 Dec 2015 22:55:40 +0000 Message-Id: <1449010541-3767-3-git-send-email-stefan.wahren@i2se.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1449010541-3767-1-git-send-email-stefan.wahren@i2se.com> References: <1449010541-3767-1-git-send-email-stefan.wahren@i2se.com> X-Provags-ID: V03:K0:ynudUg8vqXFWQzf2syQaHDwhCCscv+nC4MtplgPEwgekFrd1O5z cee+cDgiYWQwBCPbLUdOHQ0rdlCvXSyjz+xHkkIJH8YNwzLTaZPjmhGrA7oMttJgHtv4sHT OMAOpX5c42u2mCJ83ZYfIGwLqL2GIY8S+8BSQS6MW9AHz3Csm7TOH8ToMU6rm8T5zR2PBtx hMpryNfbtkLAy7cnH/SUA== X-UI-Out-Filterresults: notjunk:1; V01:K0:BVAKKr1wSuo=:9i5b5lMXtfZlWnVJv+FdPY Hk/o7ZyW+e7KucGJtlvvuq+UW5DQpzpVQKI4tvIHNUKXeU/+l7G6oc8uojGUDxFBc4AAS7FAV IVn3aIYKMWOEHX1PI3HT5XDM45nG4tEw3JyzFMFTG5woBCtDaJWUQU1+P3Q/W44/wiS0gDqwN Isn3JV7mpmK+5p1DwgAZjZMVIHa65LcGZntqLiGHZCbF5kmpMhAlNevnDejT7Ppp89VsjIHaI AlBL3i2SAtCCnY/ogmLAqGno2IILuMEde6KOYGMCuy3uFs13xPdrZLZmRvH84g2uaz5/T3N9T sTdjh9NXEKaWrM5/K6aOKYWIKnpU8hrBKU8R5nIjPTOCawo53prH9vtVzFOkJfg0haIUZSJlB uAgnWvuBDs/eJ2RtZhQlN9C/j7L6qiZj6FgEOQOXvm6KK5QZIZ/9SM+aXP24eQ8qPqGjWJEcd s1AKOGim4N94GGtDbwRyvElCP64DbIT1xagQvAhE0MzA+MCvhzsrhSsrmt9NaukycjsIqyGc6 MPZcfh1gRRbZHyCsCuAZveOVpMHD2S+ku6qIP/Ek3T6DIwtxnQPSdkrPWYHWOHpGfCq4fFP6F fFTnGx3CE4B2gU5OlD5o7wvS961+0yZwv7giCO5B2hEHK6zP0s4P/HrSMrFS2iZKYcL4F+Mw6 6IXzh1aLbKNIc6gRAcs6V2Q+6Fs49+IlUN+ZROb9fZtQRu5oqI+Kr946t3NYmnM9UGEc= X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151201_145638_674325_305F1E6C X-CRM114-Status: GOOD ( 10.15 ) X-Spam-Score: -2.6 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Stefan Wahren , linux-pwm@vger.kernel.org, Remi Pommarel , linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_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 It's possible that the pwm clock become an orphan. So better check the result of clk_get_rate in order to prevent a division by zero. Signed-off-by: Stefan Wahren Reviewed-by: Eric Anholt Reviewed-by: Eric Anholt --- drivers/pwm/pwm-bcm2835.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c index 174cca9..31a6992 100644 --- a/drivers/pwm/pwm-bcm2835.c +++ b/drivers/pwm/pwm-bcm2835.c @@ -65,7 +65,15 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); - unsigned long scaler = NSEC_PER_SEC / clk_get_rate(pc->clk); + unsigned long rate = clk_get_rate(pc->clk); + unsigned long scaler; + + if (!rate) { + dev_err(pc->dev, "failed to get clock rate\n"); + return -EINVAL; + } + + scaler = NSEC_PER_SEC / rate; if (period_ns <= MIN_PERIOD) { dev_err(pc->dev, "period %d not supported, minimum %d\n",