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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 68858C388F7 for ; Sat, 7 Nov 2020 22:33:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2269E20885 for ; Sat, 7 Nov 2020 22:33:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727454AbgKGWdN (ORCPT ); Sat, 7 Nov 2020 17:33:13 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:41118 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725838AbgKGWdN (ORCPT ); Sat, 7 Nov 2020 17:33:13 -0500 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1kbWlZ-005qOv-8H; Sat, 07 Nov 2020 23:33:01 +0100 Date: Sat, 7 Nov 2020 23:33:01 +0100 From: Andrew Lunn To: Joe Perches Cc: Alex Shi , Florian Fainelli , Vivien Didelot , Vladimir Oltean , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net/dsa: remove unused macros to tame gcc warning Message-ID: <20201107223301.GY933237@lunn.ch> References: <1604641050-6004-1-git-send-email-alex.shi@linux.alibaba.com> <20201106141820.GP933237@lunn.ch> <24690741-cc10-eec1-33c6-7960c8b7fac6@gmail.com> <6ed68a7898c5505d3106223b7ad47950a0c79dc3.camel@perches.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <6ed68a7898c5505d3106223b7ad47950a0c79dc3.camel@perches.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 07, 2020 at 09:39:42AM -0800, Joe Perches wrote: > On Sat, 2020-11-07 at 20:54 +0800, Alex Shi wrote: > > 在 2020/11/7 上午12:39, Florian Fainelli 写道: > > > > It is good to remember that there are multiple readers of source > > > > files. There is the compiler which generates code from it, and there > > > > is the human trying to understand what is going on, what the hardware > > > > can do, how we could maybe extend the code in the future to make use > > > > of bits are currently don't, etc. > > > > > > > > The compiler has no use of these macros, at the moment. But i as a > > > > human do. It is valuable documentation, given that there is no open > > > > datasheet for this hardware. > > > > > > > > I would say these warnings are bogus, and the code should be left > > > > alone. > > > Agreed, these definitions are intended to document what the hardware > > > does. These warnings are getting too far. > > > > Thanks for all comments! I agree these info are much meaningful. > > Is there other way to tame the gcc warning? like put them into a .h file > > or covered by comments? > > Does _any_ version of gcc have this warning on by default? > > I still think my proposal of moving the warning from W=2 to W=3 > quite reasonable. > > Another possibility is to turn the warning off altogether. Lets tern the question around first. How many real bugs have you found with this warning? Places where the #define should of been used, but was not? Then we can get an idea of the value of this warning. My guess would be, its value is ~ 0 for the kernel. If so, we should just turn it off. Andrew