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=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 86A4EC3E8C5 for ; Wed, 18 Nov 2020 18:00:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E9A5221F8 for ; Wed, 18 Nov 2020 18:00:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="BCJ2jt2h" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726431AbgKRSAT (ORCPT ); Wed, 18 Nov 2020 13:00:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725446AbgKRSAT (ORCPT ); Wed, 18 Nov 2020 13:00:19 -0500 Received: from mail-wr1-x441.google.com (mail-wr1-x441.google.com [IPv6:2a00:1450:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1676C0613D4 for ; Wed, 18 Nov 2020 10:00:18 -0800 (PST) Received: by mail-wr1-x441.google.com with SMTP id u12so3163211wrt.0 for ; Wed, 18 Nov 2020 10:00:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=kSX2h8dho1jTZMReBcO99jxjfM1dQZAbHWvgkhl4Rfk=; b=BCJ2jt2hfA6BvRuYMPXKmgTI82x60gmLNsrr2a1qGlAezz8GiKCk5n1pGpPG5qAnYQ h283T6qbm6awkyXWUFnbrxgRMuAUd9uncB2RKLKvF56thWERCpCfStq48QrTg+GMpuCc V9QGy7J7AVwIQEnbc6B1vm4KxP93BdjjVsYdf9Ls2YdxkBg4ab1wvkEdmoT7xLJ3CheZ zaCM2MHHehpO5c01s15hXQLfXmEQv1G9d7nEzJjLvPnjcQem+sLuHoUdAqWpYiK01SG5 5lqFz9wotwcRIzObDEpZgObSb5V69kslCs/3cNuovjsxOMiRHhGNU+oj9egZDsU1F130 8ixA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=kSX2h8dho1jTZMReBcO99jxjfM1dQZAbHWvgkhl4Rfk=; b=htoiF9+UZOakd89+2fLRyCZAUJTKlLU9iqHgeqAUYWzpJxn81ztAvWymxFvl4+10Wo EVX+B9jv6kDpIbEqm7QM6QlYfdKp0UAh7H+Mm40Iebms+oDVC2nePBElrKoFLbBTVU8y zfcgXrQTQcuNFi4rs6zSFPJxF7ekj3xO9urlHQEkzyKfPNMCjsq2pH3AVSN9VIjgHNMQ G3I3xC7HWVbaReh1P+JB4Kokxiy6bq1OixpI/AAkN1HUFk7nOr5Ev5XX/kD3m0mvUOJs egBW8Yip3gtdVWc+pp9Dv6FcST/1sObXjWf/BrhrDtfIrjae4kEmMQPyEmYx9+gsNdJF e03A== X-Gm-Message-State: AOAM530y0TWvjSpmM7fwWPFXlmBOMFTTm7oB+TMJtjjcTCsKGq8GeAKc IlpIgyMWvTF0sUofVmHARXU= X-Google-Smtp-Source: ABdhPJxlyLXMffLx+NaJJ2zOl0UYub6Z8b0Hchu7mAr6e4EdvAfd0O3HCFg+XDkoAeHV96lKrllCFw== X-Received: by 2002:adf:ead1:: with SMTP id o17mr6061429wrn.396.1605722417757; Wed, 18 Nov 2020 10:00:17 -0800 (PST) Received: from localhost ([217.111.27.204]) by smtp.gmail.com with ESMTPSA id 34sm35917732wrq.27.2020.11.18.10.00.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Nov 2020 10:00:16 -0800 (PST) Date: Wed, 18 Nov 2020 19:00:14 +0100 From: Thierry Reding To: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= Cc: Vijayakannan Ayyathurai , kbuild-all@lists.01.org, Linux Memory Management List , "Lai, Poey Seng" , "Vineetha G. Jaya Kumaran" , Andy Shevchenko , linux-kernel@vger.kernel.org, kernel@pengutronix.de, kernel test robot Subject: Re: [PATCH RFC] pwm: keembay: Fix build failure with -Os Message-ID: <20201118180014.GC3552669@ulmo> References: <202011160303.qi5aRChY-lkp@intel.com> <20201116090804.206286-1-u.kleine-koenig@pengutronix.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="KN5l+BnMqAQyZLvT" Content-Disposition: inline In-Reply-To: <20201116090804.206286-1-u.kleine-koenig@pengutronix.de> User-Agent: Mutt/1.14.7 (2020-08-29) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --KN5l+BnMqAQyZLvT Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Nov 16, 2020 at 10:08:04AM +0100, Uwe Kleine-K=C3=B6nig wrote: > The driver used this construct: >=20 > #define KMB_PWM_LEADIN_MASK GENMASK(30, 0) >=20 > static inline void keembay_pwm_update_bits(struct keembay_pwm *priv, u32= mask, > u32 val, u32 offset) > { > u32 buff =3D readl(priv->base + offset); >=20 > buff =3D u32_replace_bits(buff, val, mask); > writel(buff, priv->base + offset); > } >=20 > ... > keembay_pwm_update_bits(priv, KMB_PWM_LEADIN_MASK, 0, > KMB_PWM_LEADIN_OFFSET(pwm->hwpwm)); >=20 > With CONFIG_CC_OPTIMIZE_FOR_SIZE the compiler (here: gcc 10.2.0) this > triggers: >=20 > In file included from /home/uwe/gsrc/linux/drivers/pwm/pwm-keembay.c:16: > In function =E2=80=98field_multiplier=E2=80=99, > inlined from =E2=80=98keembay_pwm_update_bits=E2=80=99 at /home/uwe/= gsrc/linux/include/linux/bitfield.h:124:17: > /home/uwe/gsrc/linux/include/linux/bitfield.h:119:3: error: call to =E2= =80=98__bad_mask=E2=80=99 declared with attribute error: bad bitfield mask > 119 | __bad_mask(); > | ^~~~~~~~~~~~ > In function =E2=80=98field_multiplier=E2=80=99, > inlined from =E2=80=98keembay_pwm_update_bits=E2=80=99 at /home/uwe/= gsrc/linux/include/linux/bitfield.h:154:1: > /home/uwe/gsrc/linux/include/linux/bitfield.h:119:3: error: call to =E2= =80=98__bad_mask=E2=80=99 declared with attribute error: bad bitfield mask > 119 | __bad_mask(); > | ^~~~~~~~~~~~ >=20 > The compiler doesn't seem to be able to notice that with field being > 0x3ffffff the expression >=20 > if ((field | (field - 1)) & ((field | (field - 1)) + 1)) > __bad_mask(); >=20 > can be optimized away. >=20 > So use __always_inline and document the problem in a comment to fix > this. >=20 > Reported-by: kernel test robot > Signed-off-by: Uwe Kleine-K=C3=B6nig > --- > Hello, >=20 > I'm not sure this is the right fix. Maybe the bitfield stuff can be > changed somehow to make this problem go away, too? >=20 > Best regards > Uwe >=20 > drivers/pwm/pwm-keembay.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) Applied, thanks. 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