Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756820AbcCCIYW (ORCPT ); Thu, 3 Mar 2016 03:24:22 -0500 Received: from sauhun.de ([89.238.76.85]:54750 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755432AbcCCIYV (ORCPT ); Thu, 3 Mar 2016 03:24:21 -0500 From: Wolfram Sang To: linux-kernel@vger.kernel.org Cc: Wolfram Sang , Wim Van Sebroeck , Guenter Roeck , linux-watchdog@vger.kernel.org Subject: [PATCH v2] watchdog: tangox_wdt: test clock rate to avoid division by 0 Date: Thu, 3 Mar 2016 09:24:12 +0100 Message-Id: <1456993453-7958-1-git-send-email-wsa@the-dreams.de> X-Mailer: git-send-email 2.7.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1394 Lines: 52 From: Wolfram Sang The clk API may return 0 on clk_get_rate, so we should check the result before using it as a divisor. For this, refactor the code to use a central error path. Signed-off-by: Wolfram Sang --- drivers/watchdog/tangox_wdt.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/watchdog/tangox_wdt.c b/drivers/watchdog/tangox_wdt.c index 709c1ed6fd79b9..cfbed7e051b619 100644 --- a/drivers/watchdog/tangox_wdt.c +++ b/drivers/watchdog/tangox_wdt.c @@ -139,6 +139,10 @@ static int tangox_wdt_probe(struct platform_device *pdev) return err; dev->clk_rate = clk_get_rate(dev->clk); + if (!dev->clk_rate) { + err = -EINVAL; + goto err; + } dev->wdt.parent = &pdev->dev; dev->wdt.info = &tangox_wdt_info; @@ -171,10 +175,8 @@ static int tangox_wdt_probe(struct platform_device *pdev) } err = watchdog_register_device(&dev->wdt); - if (err) { - clk_disable_unprepare(dev->clk); - return err; - } + if (err) + goto err; platform_set_drvdata(pdev, dev); @@ -187,6 +189,10 @@ static int tangox_wdt_probe(struct platform_device *pdev) dev_info(&pdev->dev, "SMP86xx/SMP87xx watchdog registered\n"); return 0; + + err: + clk_disable_unprepare(dev->clk); + return err; } static int tangox_wdt_remove(struct platform_device *pdev) -- 2.7.0