From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58FCCC43381 for ; Fri, 29 Mar 2019 12:41:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 260F220700 for ; Fri, 29 Mar 2019 12:41:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="hCPtFVms"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="hCPtFVms" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729551AbfC2Mlo (ORCPT ); Fri, 29 Mar 2019 08:41:44 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:48812 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729483AbfC2Mln (ORCPT ); Fri, 29 Mar 2019 08:41:43 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id BCD4E6053B; Fri, 29 Mar 2019 12:41:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1553863302; bh=svoyHdsfknhYZkHlh1dpyQziKSCvrtzLyfMm1dSAI2M=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=hCPtFVmsJr3GfqDWDDdB8jsX7Mega+vFMkNMukDVFtRXTRooKksZzdKPCwd6zpNDv 2N7M7iQXwSuhZeAdTluxH7wnlkbe5bWRuBnztXEBLLaFfDACXSWRpvSeSHJ5Ig+dIG WLe08ovqgQvy1ClmAvqvxI2BTVgeT5e5x37J3b8o= Received: from [10.204.79.83] (blr-c-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: mojha@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id C3F0A6053B; Fri, 29 Mar 2019 12:41:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1553863302; bh=svoyHdsfknhYZkHlh1dpyQziKSCvrtzLyfMm1dSAI2M=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=hCPtFVmsJr3GfqDWDDdB8jsX7Mega+vFMkNMukDVFtRXTRooKksZzdKPCwd6zpNDv 2N7M7iQXwSuhZeAdTluxH7wnlkbe5bWRuBnztXEBLLaFfDACXSWRpvSeSHJ5Ig+dIG WLe08ovqgQvy1ClmAvqvxI2BTVgeT5e5x37J3b8o= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C3F0A6053B Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=mojha@codeaurora.org Subject: Re: [PATCH] clk:mmp: clk-mix.c fix divide-by-zero To: nixiaoming , mturquette@baylibre.com, sboyd@kernel.org, chao.xie@marvell.com Cc: linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org References: <1553859960-31501-1-git-send-email-nixiaoming@huawei.com> From: Mukesh Ojha Message-ID: <2882780e-ac45-c5e7-26fd-a1882a67113a@codeaurora.org> Date: Fri, 29 Mar 2019 18:11:34 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <1553859960-31501-1-git-send-email-nixiaoming@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/29/2019 5:16 PM, nixiaoming wrote: > The _get_div function has a branch with a return value of 0 > Add a check on the return value of _get_div to avoid divide-by-zero > > Signed-off-by: nixiaoming Fix the below minor comments.. Otherwise things look good..you can take mine Reviewed-by: Mukesh Ojha after fixing it. Cheers, -Mukesh > --- > drivers/clk/mmp/clk-mix.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/clk/mmp/clk-mix.c b/drivers/clk/mmp/clk-mix.c > index 90814b2..9d152c2 100644 > --- a/drivers/clk/mmp/clk-mix.c > +++ b/drivers/clk/mmp/clk-mix.c > @@ -245,6 +245,8 @@ static int mmp_clk_mix_determine_rate(struct clk_hw *hw, > div_val_max = _get_maxdiv(mix); > for (j = 0; j < div_val_max; j++) { > div = _get_div(mix, j); > + if (!div) /* avoid divide-by-zero */ Please move this comment at the top of the check. > + continue; > mix_rate = parent_rate / div; > gap = abs(mix_rate - req->rate); > if (!parent_best || gap < gap_best) { > @@ -341,6 +343,8 @@ static unsigned long mmp_clk_mix_recalc_rate(struct clk_hw *hw, > shift = mix->reg_info.shift_div; > > div = _get_div(mix, MMP_CLK_BITS_GET_VAL(mux_div, width, shift)); > + if (!div) /* avoid divide-by-zero */ ditto > + return -EINVAL; > > return parent_rate / div; > }