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 CECECC433F5 for ; Sat, 8 Jan 2022 00:56:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232736AbiAHA4f (ORCPT ); Fri, 7 Jan 2022 19:56:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232324AbiAHA4G (ORCPT ); Fri, 7 Jan 2022 19:56:06 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C7A1C061746; Fri, 7 Jan 2022 16:56:06 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 4B402B827C3; Sat, 8 Jan 2022 00:56:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05575C36AEB; Sat, 8 Jan 2022 00:56:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641603364; bh=st53BHQLvyLzo/b3A3D4UNXb37sg+UZodRPGTnSnFWY=; h=In-Reply-To:References:Subject:From:Cc:To:Date:From; b=Hpfsrk/In3BFFgMIQLxj0MO5/DK2K22Qwq6mtxs+4GXPHnLzAyeDZNyzTWQANwwym WJgyirFL+ZS3jclL4WCvoi9G2O8JTMW4zvfqMGg23mCZ7ZfCuzzYd6fkZiTyOF9tak FZE84sT8tK5nfJliA3OXnqI4cuuZ8z33DoeFwwHyQDSaI41mpFV46D1r2xTvPhseub sYyCn/YCvpAXZeSCLWi1ohQA7Dj08JwS67ynz9+JV6j3/nz4akxzGnXY26fGx8nuVI xuJlNNbRjMEwS3A7/P/3oeYLj1zoevo3iOUXKoxpPB2GyQapQWUBr0O4PskE0Cf1gf Ks8K5M/MXYENA== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <20211209163720.106185-3-nikita@trvn.ru> References: <20211209163720.106185-1-nikita@trvn.ru> <20211209163720.106185-3-nikita@trvn.ru> Subject: Re: [PATCH 2/4] clk: qcom: clk-rcg2: Make sure to not write d=0 to the NMD register From: Stephen Boyd Cc: bjorn.andersson@linaro.org, agross@kernel.org, tdas@codeaurora.org, joonwoop@codeaurora.org, svarbanov@mm-sol.com, linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, ~postmarketos/upstreaming@lists.sr.ht, Nikita Travkin To: Nikita Travkin , linus.walleij@linaro.org, mturquette@baylibre.com Date: Fri, 07 Jan 2022 16:56:02 -0800 User-Agent: alot/0.9.1 Message-Id: <20220108005604.05575C36AEB@smtp.kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Nikita Travkin (2021-12-09 08:37:18) > Sometimes calculation of d value may result in 0 because of the > rounding after integer division. This causes the following error: >=20 > [ 113.969689] camss_gp1_clk_src: rcg didn't update its configuration. > [ 113.969754] WARNING: CPU: 3 PID: 35 at drivers/clk/qcom/clk-rcg2.c:122= update_config+0xc8/0xdc >=20 > Make sure that D value is never zero. >=20 > Fixes: 7f891faf596e ("clk: qcom: clk-rcg2: Add support for duty-cycle for= RCG") > Signed-off-by: Nikita Travkin > --- > drivers/clk/qcom/clk-rcg2.c | 4 ++++ > 1 file changed, 4 insertions(+) >=20 > diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c > index 6964cf914b60..fdfd43e2a01b 100644 > --- a/drivers/clk/qcom/clk-rcg2.c > +++ b/drivers/clk/qcom/clk-rcg2.c > @@ -424,6 +424,10 @@ static int clk_rcg2_set_duty_cycle(struct clk_hw *hw= , struct clk_duty *duty) > if (d > mask) > d =3D mask; > =20 > + /* Hardware can't handle d=3D0, make sure it's at least 1 */ > + if (!d) > + d =3D 1; Maybe clamp() would be better /* * Check bit widths of 2d. If D is too big reduce duty cycle and * ensure it is non-zero. */ clamp(d, 1, mask); > + > if ((d / 2) > (n - m)) > d =3D (n - m) * 2; > else if ((d / 2) < (m / 2))