From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail3-relais-sop.national.inria.fr (mail3-relais-sop.national.inria.fr [192.134.164.104]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C853A39A7E5; Mon, 10 Aug 2026 06:53:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.134.164.104 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786344822; cv=none; b=OEVHkiA2o/xQDn/4qALtNH07zPSjlPpbX5xb2SB9EIFbg84TShZBDZfnvRFFXEjRZPgzgHzzzkApbFWoGK2wM0PbVz91u4O5imMyuvBI+uywECGj4w8KT1mvytGFr+y0LNnc3NuVI4x+fhs/YMg8E6LhMx8W7WiyH/lYlSRkeq8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786344822; c=relaxed/simple; bh=eRpC2wSKwmWwBIePGghUFkoti00q8vTs5+GApCdglVE=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=Jp6lV4KYAdpmiRTjzQ5PqrSMSrXXzX5gTydvhdk2zOxFQ/O3umm69b8D4pyau3QXuYTXPY97R7qlTJvNX//1iI3n3YTqehJx/OhxwdOCQhPpEtXRsS+lYB0H0OLALM1KRgWmkQRD70t7C5qGauDerIuiL5naQxDIHOkunx6SIM4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=inria.fr; spf=pass smtp.mailfrom=inria.fr; dkim=pass (1024-bit key) header.d=inria.fr header.i=@inria.fr header.b=Lj1HoXbj; arc=none smtp.client-ip=192.134.164.104 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=inria.fr Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=inria.fr Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=inria.fr header.i=@inria.fr header.b="Lj1HoXbj" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=inria.fr; s=dc; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=Jy1mXnOgzwP16J9PCcnnI5CZdWdJZHs+cXmX0d/fN1c=; b=Lj1HoXbja2kiLjCjKULFfF1rJUzaQ6tQGLrrrp9SklOaB4y8ZKAzi9Ew DrQHwusgOtscPefMQ3L32BvcaMWG8z+mDViOCSLCWUtQJ+lB27F2S76hY iMDD3cwK13r1jEg//+hzDok43SC4YxdgzGTDd3/cuHtp7hcLrtqAwSAY7 o=; X-CSE-ConnectionGUID: kZFkhPRgR+e+Gu/As7/hmg== X-CSE-MsgGUID: 74nADR8WQQKMkAp4G55ISg== Authentication-Results: mail3-relais-sop.national.inria.fr; dkim=none (message not signed) header.i=none; spf=SoftFail smtp.mailfrom=julia.lawall@inria.fr; dmarc=fail (p=none dis=none) d=inria.fr X-IronPort-AV: E=Sophos;i="6.25,215,1779141600"; d="scan'208";a="153948079" Received: from 88-188-149-159.subs.proxad.net (HELO hadrien.home) ([88.188.149.159]) by mail3-relais-sop.national.inria.fr with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2026 08:53:37 +0200 Date: Mon, 10 Aug 2026 08:53:35 +0200 (CEST) From: Julia Lawall To: Guru Das Srinagesh cc: Nicolas Palix , Michael Turquette , Stephen Boyd , linux-kernel@vger.kernel.org, cocci@inria.fr, Brian Masney , linux-clk@vger.kernel.org Subject: Re: [PATCH v3] coccinelle: Detect clk_register() anti-pattern In-Reply-To: <20260809-cocci-clk-register-v3-1-60d036e13370@gurudas.dev> Message-ID: References: <20260809-cocci-clk-register-v3-1-60d036e13370@gurudas.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII On Sun, 9 Aug 2026, Guru Das Srinagesh wrote: > Enforce commit 12a0fd23e870 ("clk: Print an error when clk registration > fails"): clk_register(), clk_hw_register(), and their devm_/of_ variants > log their own error on failure, so driver-side error prints after these > calls are redundant. > > Two independent match families, one per return-value convention: > pointer return checked via IS_ERR() (clk_register()/devm_clk_register()), > and int return checked via a nonzero value (clk_hw_register()/ > devm_clk_hw_register()/of_clk_hw_register()). Both families match > regardless of whether the redundant message's "if" also has a trailing > "else", via an "else S" clause with S otherwise unused. > > In "patch" mode, removing the redundant message also collapses the > enclosing braces when only one statement remains, and deletes the whole > "if" when the message was already the only (braceless) statement. > > Assisted-by: Claude:claude-sonnet-5 coccinelle > Signed-off-by: Guru Das Srinagesh > --- Hello, Thanks for the update, which I will look into shortly. But you are not structuring your patches in the right way. The part above the first --- is what will go into the git comit. That looks fine. But I don't understand what is the big pile of text below the ---. When there is a new version, I want to see what has changed as quickly as possible. So the changes in v3 should be the first thing that I see below the ---, not the last thing. For the following information, I'm not sure it should be here at all. Either it is important, in which case it should be above the --- so people in the future can easily benefit from it, or it is not important, in which case it should be dropped. julia > Add a Coccinelle semantic patch enforcing commit 12a0fd23e870 ("clk: > Print an error when clk registration fails"): flags, and in "patch" > mode removes, driver-side error prints that are now redundant after > clk_register()/clk_hw_register() and their devm_/of_ variants. > > Two independent match families, one per return-value convention. > > Pointer return, IS_ERR()-checked (clk_register()/devm_clk_register()), > e.g. drivers/clk/clk-xgene.c:152-157: > > clk = clk_register(dev, &apmclk->hw); > if (IS_ERR(clk)) { > - pr_err("%s: could not register clk %s\n", __func__, name); > kfree(apmclk); > return NULL; > } > > Int return, nonzero-checked (clk_hw_register()/devm_clk_hw_register()/ > of_clk_hw_register()), e.g. drivers/clk/meson/meson-clkc-utils.c:49-54: > > ret = devm_clk_hw_register(dev, hw); > - if (ret) { > - dev_err(dev, "registering %s clock failed\n", > - hw->init->name); > + if (ret) > return ret; > - } > > Already-braceless single-statement case: the whole "if" is deleted > instead of just the message, e.g. drivers/clk/ux500/clk-sysctrl.c:171-175: > > clk_reg = devm_clk_register(clk->dev, &clk->hw); > - if (IS_ERR(clk_reg)) > - dev_err(dev, "clk_sysctrl: clk_register failed\n"); > > return clk_reg; > > Matches regardless of whether the "if" also has a trailing "else", via > an "else S" clause with S otherwise unused, e.g. > drivers/media/platform/microchip/microchip-isc-clk.c:269-275: > > isc_clk->clk = clk_register(isc->dev, &isc_clk->hw); > - if (IS_ERR(isc_clk->clk)) { > - dev_err(isc->dev, "%s: clock register fail\n", clk_name); > + if (IS_ERR(isc_clk->clk)) > return PTR_ERR(isc_clk->clk); > - } else if (id == ISC_MCK) { > + else if (id == ISC_MCK) { > of_clk_add_provider(np, of_clk_src_simple_get, isc_clk->clk); > } > > Testing: > - Baseline: coccinelle 1.3.1, the Torvalds tree at v7.2-rc5. > - "make coccicheck COCCI= MODE=report M=drivers/clk" produced 73 > hits, unchanged after this revision, and verified to have zero false > positives. > - All four modes (report/context/patch/org) verified via "make > coccicheck COCCI= MODE= [M=]" against the > drivers/clk baseline and the new else-branch case above. > - "make coccicheck COCCI= MODE=report" (whole tree, no M=) finds > 94 hits; the 21 outside drivers/clk are not part of this series. > --- > Changes in v3 (Julia): > - Match an "if" regardless of a trailing "else" (else S, S unused), > across context/patch/report/org rules for both families. Found via > this to be a real, previously-invisible case in > drivers/media/platform/microchip/microchip-isc-clk.c. > - Fix the org-mode script rules: cocci.print_main() takes (message, > position), not just a position; the previous calls omitted the > message entirely. > - Drop the MAINTAINERS addition from v2 per Julia's comment that a > specific maintainer isn't needed for this file. > - Link to v2: https://patch.msgid.link/20260803-cocci-clk-register-v2-1-22e789f75f98@gurudas.dev > > Changes in v2 (Julia): > - Use a literal function-name disjunction instead of a regex identifier, > enabling spatch's file pre-filter optimization. > - In "patch" mode, drop braces when only one statement remains, and > delete the whole "if" when the message was the only (braceless) > statement. > - Drop two never-observed condition variants (IS_ERR(clk) == 1, ret != > 0); keep the one with real precedent (ret < 0). > - Link to v1: https://patch.msgid.link/20260802-cocci-clk-register-v1-1-df68afcb1eef@gurudas.dev > --- > scripts/coccinelle/api/clk_register.cocci | 165 ++++++++++++++++++++++++++++++ > 1 file changed, 165 insertions(+) > > diff --git a/scripts/coccinelle/api/clk_register.cocci b/scripts/coccinelle/api/clk_register.cocci > new file mode 100644 > index 000000000000..150279827bf4 > --- /dev/null > +++ b/scripts/coccinelle/api/clk_register.cocci > @@ -0,0 +1,165 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/// Remove error messages after clk registration failures, because > +/// clk_register(), clk_hw_register(), and their variants already log > +/// an error when they fail. See commit 12a0fd23e870 ("clk: Print an > +/// error when clk registration fails"). > +// > +// Confidence: Medium > +// Options: --include-headers > + > +virtual patch > +virtual context > +virtual org > +virtual report > + > +@depends on context@ > +expression clk; > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > +statement S; > +@@ > + > +clk = \(clk_register\|devm_clk_register\)(...); > +if ( IS_ERR(clk) ) > +{ > +... > +*voidfn(...); > +... > +} > +else S > + > +@depends on patch@ > +expression clk; > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > +@@ > + > +clk = \(clk_register\|devm_clk_register\)(...); > +-if ( IS_ERR(clk) ) > +-voidfn(...); > + > +@depends on patch@ > +expression clk; > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > +statement S, S_else; > +@@ > + > +clk = \(clk_register\|devm_clk_register\)(...); > +if ( IS_ERR(clk) ) > +( > +-{ > +-voidfn(...); > +S > +-} > +| > +{ > +... > +-voidfn(...); > +... > +} > +) > +else S_else > + > +@r1 depends on org || report@ > +position p1; > +expression clk; > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > +statement S; > +@@ > + > +clk = \(clk_register\|devm_clk_register\)(...); > +if ( IS_ERR(clk) ) > +{ > +... > +voidfn@p1(...); > +... > +} > +else S > + > +@depends on context@ > +expression ret; > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > +statement S; > +@@ > + > +ret = \(clk_hw_register\|devm_clk_hw_register\|of_clk_hw_register\)(...); > +if ( \( ret \| ret < 0 \) ) > +{ > +... > +*voidfn(...); > +... > +} > +else S > + > +@depends on patch@ > +expression ret; > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > +@@ > + > +ret = \(clk_hw_register\|devm_clk_hw_register\|of_clk_hw_register\)(...); > +-if ( \( ret \| ret < 0 \) ) > +-voidfn(...); > + > +@depends on patch@ > +expression ret; > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > +statement S, S_else; > +@@ > + > +ret = \(clk_hw_register\|devm_clk_hw_register\|of_clk_hw_register\)(...); > +if ( \( ret \| ret < 0 \) ) > +( > +-{ > +-voidfn(...); > +S > +-} > +| > +{ > +... > +-voidfn(...); > +... > +} > +) > +else S_else > + > +@r2 depends on org || report@ > +position p2; > +expression ret; > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > +statement S; > +@@ > + > +ret = \(clk_hw_register\|devm_clk_hw_register\|of_clk_hw_register\)(...); > +if ( \( ret \| ret < 0 \) ) > +{ > +... > +voidfn@p2(...); > +... > +} > +else S > + > +@script:python depends on org@ > +p1 << r1.p1; > +@@ > + > +msg = "line %s is redundant because clk_register() already prints an error on failure" % (p1[0].line) > +cocci.print_main(msg, p1) > + > +@script:python depends on report@ > +p1 << r1.p1; > +@@ > + > +msg = "line %s is redundant because clk_register() already prints an error on failure" % (p1[0].line) > +coccilib.report.print_report(p1[0], msg) > + > +@script:python depends on org@ > +p2 << r2.p2; > +@@ > + > +msg = "line %s is redundant because clk_hw_register() already prints an error on failure" % (p2[0].line) > +cocci.print_main(msg, p2) > + > +@script:python depends on report@ > +p2 << r2.p2; > +@@ > + > +msg = "line %s is redundant because clk_hw_register() already prints an error on failure" % (p2[0].line) > +coccilib.report.print_report(p2[0], msg) > > --- > base-commit: f5098b6bae761e346ebcd9da7f95622c04733cff > change-id: 20260802-cocci-clk-register-951d94251af4 > > Best regards, > -- > Guru Das Srinagesh > >