Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754087AbcCBX2c (ORCPT ); Wed, 2 Mar 2016 18:28:32 -0500 Received: from mail-io0-f193.google.com ([209.85.223.193]:33087 "EHLO mail-io0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752106AbcCBX2a (ORCPT ); Wed, 2 Mar 2016 18:28:30 -0500 MIME-Version: 1.0 In-Reply-To: <1456959443-10032-1-git-send-email-wsa@the-dreams.de> References: <1456959443-10032-1-git-send-email-wsa@the-dreams.de> Date: Thu, 3 Mar 2016 00:28:29 +0100 Message-ID: Subject: Re: [PATCH v2] pwm: pwm-lpc18xx-sct: test clock rate to avoid division by 0 From: Joachim Eastwood To: Wolfram Sang Cc: "linux-kernel@vger.kernel.org" , Thierry Reding , linux-pwm@vger.kernel.org, "linux-arm-kernel@lists.infradead.org" , "Ariel D'Alessandro" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1058 Lines: 34 Hi Wolfram, On 2 March 2016 at 23:57, Wolfram Sang wrote: > 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. > > Signed-off-by: Wolfram Sang > --- > drivers/pwm/pwm-lpc18xx-sct.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c > index 9163085101bc94..9861fed4e67d04 100644 > --- a/drivers/pwm/pwm-lpc18xx-sct.c > +++ b/drivers/pwm/pwm-lpc18xx-sct.c > @@ -360,6 +360,11 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev) > } > > lpc18xx_pwm->clk_rate = clk_get_rate(lpc18xx_pwm->pwm_clk); > + if (!lpc18xx_pwm->clk_rate) { > + dev_err(&pdev->dev, "pwm clock has no frequency\n"); > + ret = -EINVAL; > + goto disable_pwmclk; > + } Acked-by: Joachim Eastwood Thanks for fixing this. regards, Joachim Eastwood