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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 74BC8C2BB85 for ; Fri, 10 Apr 2020 19:15:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5484C20732 for ; Fri, 10 Apr 2020 19:15:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726687AbgDJTPE (ORCPT ); Fri, 10 Apr 2020 15:15:04 -0400 Received: from alexa-out-sd-02.qualcomm.com ([199.106.114.39]:63184 "EHLO alexa-out-sd-02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726142AbgDJTPE (ORCPT ); Fri, 10 Apr 2020 15:15:04 -0400 Received: from unknown (HELO ironmsg-SD-alpha.qualcomm.com) ([10.53.140.30]) by alexa-out-sd-02.qualcomm.com with ESMTP; 10 Apr 2020 12:15:04 -0700 Received: from gurus-linux.qualcomm.com ([10.46.162.81]) by ironmsg-SD-alpha.qualcomm.com with ESMTP; 10 Apr 2020 12:15:04 -0700 Received: by gurus-linux.qualcomm.com (Postfix, from userid 383780) id 06A1F4BED; Fri, 10 Apr 2020 12:15:03 -0700 (PDT) Date: Fri, 10 Apr 2020 12:15:03 -0700 From: Guru Das Srinagesh To: linux-pwm@vger.kernel.org Cc: Thierry Reding , Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= , Subbaraman Narayanamurthy , David Collins , linux-kernel@vger.kernel.org, Michael Turquette , Stephen Boyd , linux-clk@vger.kernel.org, David Laight , Arnd Bergmann Subject: Re: [PATCH v12 10/11] clk: pwm: Use 64-bit division function Message-ID: <20200410191503.GA21571@codeaurora.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org + Arnd, David On Wed, Apr 08, 2020 at 11:52:39PM -0700, Guru Das Srinagesh wrote: > Since the PWM framework is switching struct pwm_args.period's datatype > to u64, prepare for this transition by using div64_u64 to handle a > 64-bit divisor. > > Also ensure that divide-by-zero (with fixed_rate as denominator) does > not happen with an explicit check with probe failure as a consequence. > > Cc: Michael Turquette > Cc: Stephen Boyd > Cc: linux-clk@vger.kernel.org > > Signed-off-by: Guru Das Srinagesh > --- > drivers/clk/clk-pwm.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/clk/clk-pwm.c b/drivers/clk/clk-pwm.c > index 87fe0b0e..86f2e2d 100644 > --- a/drivers/clk/clk-pwm.c > +++ b/drivers/clk/clk-pwm.c > @@ -89,7 +89,12 @@ static int clk_pwm_probe(struct platform_device *pdev) > } > > if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate)) > - clk_pwm->fixed_rate = NSEC_PER_SEC / pargs.period; > + clk_pwm->fixed_rate = div64_u64(NSEC_PER_SEC, pargs.period); > + > + if (!clk_pwm->fixed_rate) { > + dev_err(&pdev->dev, "fixed_rate cannot be zero\n"); > + return -EINVAL; > + } > > if (pargs.period != NSEC_PER_SEC / clk_pwm->fixed_rate && > pargs.period != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) { > -- Hello Arnd, David: Sorry, missed cc-ing you both to this patch while sending it out. Could you please review it when you get a chance to? Thank you. Guru Das.