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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9DADEC433FE for ; Thu, 25 Nov 2021 03:08:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238590AbhKYDLk (ORCPT ); Wed, 24 Nov 2021 22:11:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245421AbhKYDJh (ORCPT ); Wed, 24 Nov 2021 22:09:37 -0500 Received: from mail-ot1-x32a.google.com (mail-ot1-x32a.google.com [IPv6:2607:f8b0:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1FA95C0619E6; Wed, 24 Nov 2021 18:33:19 -0800 (PST) Received: by mail-ot1-x32a.google.com with SMTP id 47-20020a9d0332000000b005798ac20d72so7240176otv.9; Wed, 24 Nov 2021 18:33:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=FzruCpHTuVDhBSIsG1eTOXd9RDdSQPTEZ/7U28aWtgw=; b=gH9gEdqwyXOHMCnta4W3bG65lK1pTrnVSMIIZzyJR1B5/Ew4VqWIJfOqYW0K3SjOLD 6CEI7m4MqIH7j5jsEBArVNWBwisK6MW6hH9k5b5uGhfTBKoFGJdPZWC9vaotmaqWFlVR xR2ApiDfOzJmoTvwtBujKXBR8Sj8JDBAKAGsxp2tRGQiXNBhyChn4VQdn2w0AgGm+pgz r8kfxDxwk4gVBIN4aD8qVJpl8X5oSb589NL/5kNtCs/PKj8/rQxYF7A3pVfcW00STQPO wqR8nwSDhTvbo6mxLy6lfiUHd1NL9VGhRDIaKlsNn9y+rKhrkAQ49zBQ+oE15TpPttuj rMmw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=FzruCpHTuVDhBSIsG1eTOXd9RDdSQPTEZ/7U28aWtgw=; b=oS1MYd9Dg+lfiBcazTK7+wTfo5QH9AZzNQ61KrLlpmz54wEj5dNLYCGvK25rc7Wkql JI7bfC6rMUVHUt4Mra51I0FpDuBMAns3WjJ7yhvVRdgbMbxAybCXNtphp8P5ruocAk55 CZnL3a6YF+qPqNCGwvrgm443+2Oxb1jtUofFn79kAZ0sFJoOZ3ZXsv9MItBhN/h/z/gx OCUBOdZEFKyKuOMQWt7WjnxMFTvHEUUTgfrpgMyLBK0HtVAAunZIzBcEsynWeceCwMzf uiLvdXRiuuXqYvfEs3hhFQ1fgAGAqYHeZlnxy69u2TVcmWCW4OsaUJh2dO+N/hzYh3WM dtpA== X-Gm-Message-State: AOAM532fmMWwpV5jrj+JKPZw30jFay2eE+ZhhTdRdnmF3sph3yVoHdDy X1/k5WGdykI0A6zNqCVqGzMeSmcIJIg= X-Google-Smtp-Source: ABdhPJzQ/gsw0ESgF4EaGULaMV01pscDEYyj0XKYKKqpHrHESLg1ERw33D6cAIdLj/oIrzaWDnOWrw== X-Received: by 2002:a05:6830:44c:: with SMTP id d12mr17809980otc.66.1637807598545; Wed, 24 Nov 2021 18:33:18 -0800 (PST) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id n6sm306100otj.78.2021.11.24.18.33.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Nov 2021 18:33:18 -0800 (PST) Sender: Guenter Roeck Date: Wed, 24 Nov 2021 18:33:16 -0800 From: Guenter Roeck To: cgel.zte@gmail.com Cc: wim@linux-watchdog.org, linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, Changcheng Deng , Zeal Robot Subject: Re: [PATCH] watchdog: davinci: Use div64_ul instead of do_div Message-ID: <20211125023316.GH851427@roeck-us.net> References: <20211125014924.46297-1-deng.changcheng@zte.com.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211125014924.46297-1-deng.changcheng@zte.com.cn> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 25, 2021 at 01:49:24AM +0000, cgel.zte@gmail.com wrote: > From: Changcheng Deng > > do_div() does a 64-by-32 division. Here the divisor is an unsigned long > which on some platforms is 64 bit wide. So use div64_ul instead of do_div > to avoid a possible truncation. > > Reported-by: Zeal Robot > Signed-off-by: Changcheng Deng Reviewed-by: Guenter Roeck > --- > drivers/watchdog/davinci_wdt.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/watchdog/davinci_wdt.c b/drivers/watchdog/davinci_wdt.c > index e6eaba6bae5b..584a56893b81 100644 > --- a/drivers/watchdog/davinci_wdt.c > +++ b/drivers/watchdog/davinci_wdt.c > @@ -134,7 +134,7 @@ static unsigned int davinci_wdt_get_timeleft(struct watchdog_device *wdd) > timer_counter = ioread32(davinci_wdt->base + TIM12); > timer_counter |= ((u64)ioread32(davinci_wdt->base + TIM34) << 32); > > - do_div(timer_counter, freq); > + timer_counter = div64_ul(timer_counter, freq); > > return wdd->timeout - timer_counter; > } > -- > 2.25.1 >