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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 82A6FC74A21 for ; Wed, 10 Jul 2019 15:46:25 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5B2CA2086D for ; Wed, 10 Jul 2019 15:46:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="bN74605Y" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5B2CA2086D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=perches.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Date:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=jXGlKmPu4BmhxD8wsNCVjIFtVuA3hdAuANoMgZrWCLQ=; b=bN74605YJxU/du +MluzUnLkGbyh0M7iBPImaeZDdAC7MspmeOM/2zLkJEGYoF9JzgzJkQ7kp3qz0d2MuLHihG61KbTj LDNn7oWKVT/oY547LHRbYEofHoBUQGVe4+qgIl2GlLBTAfWNdPHtw4pXv2FO2k4ElZphYlZqx+BWD LYRVXd8EiAkEvmdUjQErmgrF5VfyQIhDqnUe35T5RhvNp1NTEM/Qmpv7dxys4d8A8jMvjX2OUwV42 hYwXuDRdi3KwFgkhfGZNe5BvVBZVQZxBf66+6IZMDPaj+OE7PvU6ELA0SdLJcV6dSukcnzTbMplRk iNRgCosAm1S3/yFbzyFg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hlEnR-0003Qu-Kd; Wed, 10 Jul 2019 15:46:17 +0000 Received: from smtprelay0085.hostedemail.com ([216.40.44.85] helo=smtprelay.hostedemail.com) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hlEnO-0003Ps-G7; Wed, 10 Jul 2019 15:46:16 +0000 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay05.hostedemail.com (Postfix) with ESMTP id C502F1802912E; Wed, 10 Jul 2019 15:46:09 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: range96_50d7d845d712e X-Filterd-Recvd-Size: 3121 Received: from XPS-9350 (cpe-23-242-196-136.socal.res.rr.com [23.242.196.136]) (Authenticated sender: joe@perches.com) by omf13.hostedemail.com (Postfix) with ESMTPA; Wed, 10 Jul 2019 15:45:54 +0000 (UTC) Message-ID: Subject: Re: [PATCH 00/12] treewide: Fix GENMASK misuses From: Joe Perches To: Russell King - ARM Linux admin , Johannes Berg Date: Wed, 10 Jul 2019 08:45:53 -0700 In-Reply-To: <20190710094337.wf2lftxzfjq2etro@shell.armlinux.org.uk> References: <5fa1fa6998332642c49e2d5209193ffe2713f333.camel@sipsolutions.net> <20190710094337.wf2lftxzfjq2etro@shell.armlinux.org.uk> User-Agent: Evolution 3.30.5-0ubuntu0.18.10.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190710_084614_672923_2AAE9EE1 X-CRM114-Status: GOOD ( 13.48 ) X-BeenThere: linux-amlogic@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devel@driverdev.osuosl.org, linux-mmc@vger.kernel.org, alsa-devel@alsa-project.org, Benjamin Fair , linux-aspeed@lists.ozlabs.org, Andrew Jeffery , Patrick Venture , openbmc@lists.ozlabs.org, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, Nancy Yuen , linux-mediatek@lists.infradead.org, dri-devel@lists.freedesktop.org, netdev@vger.kernel.org, linux-amlogic@lists.infradead.org, Andrew Morton , linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-amlogic" Errors-To: linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.org On Wed, 2019-07-10 at 10:43 +0100, Russell King - ARM Linux admin wrote: > On Wed, Jul 10, 2019 at 11:17:31AM +0200, Johannes Berg wrote: > > On Tue, 2019-07-09 at 22:04 -0700, Joe Perches wrote: > > > These GENMASK uses are inverted argument order and the > > > actual masks produced are incorrect. Fix them. > > > > > > Add checkpatch tests to help avoid more misuses too. > > > > > > Joe Perches (12): > > > checkpatch: Add GENMASK tests > > > > IMHO this doesn't make a lot of sense as a checkpatch test - just throw > > in a BUILD_BUG_ON()? I tried that. It'd can't be done as it's used in declarations and included in asm files and it uses the UL() macro. I also tried just making it do the right thing whatever the argument order. Oh well. > My personal take on this is that GENMASK() is really not useful, it's > just pure obfuscation and leads to exactly these kinds of mistakes. > > Yes, I fully understand the argument that you can just specify the > start and end bits, and it _in theory_ makes the code more readable. > > However, the problem is when writing code. GENMASK(a, b). Is a the > starting bit or ending bit? Is b the number of bits? It's confusing > and causes mistakes resulting in incorrect code. A BUILD_BUG_ON() > can catch some of the cases, but not all of them. It's a horrid little macro and I agree with Russell. I also think if it existed at all it should have been GENMASK(low, high) not GENMASK(high, low). I _______________________________________________ linux-amlogic mailing list linux-amlogic@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-amlogic