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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DF0E6C43219 for ; Mon, 8 Nov 2021 15:59:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA14C61288 for ; Mon, 8 Nov 2021 15:59:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241147AbhKHQB4 (ORCPT ); Mon, 8 Nov 2021 11:01:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236850AbhKHQBy (ORCPT ); Mon, 8 Nov 2021 11:01:54 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BBA6DC061570; Mon, 8 Nov 2021 07:59:09 -0800 (PST) Received: from zn.tnic (p200300ec2f331100b486bab6e60d7aaf.dip0.t-ipconnect.de [IPv6:2003:ec:2f33:1100:b486:bab6:e60d:7aaf]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 341131EC04DE; Mon, 8 Nov 2021 16:59:08 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1636387148; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=JALJsenIQCt4BletZS/B+Zq0YBxBp6L9Ch45cvOw8XQ=; b=LCBDSZEhct23FIVquhfAlhIS3MpLXm84rotG+ppp99dGMPWi9iJHGgKkfiFg0DoLQ+NSWf ixY2Bl+WafqAknd6kFkKb4q9SvLPR/pI4iyCTMD6S/zki4CWzqH6/1ZBq8awazUNWt4Xi0 idSLz3mdlao9wfI9n1SzGKhLH2sR0dI= Date: Mon, 8 Nov 2021 16:58:57 +0100 From: Borislav Petkov To: Geert Uytterhoeven Cc: LKML , Thomas Gleixner , Arnd Bergmann , Ayush Sawal , Greg Kroah-Hartman , Rohit Maheshwari , Steven Rostedt , Vinay Kumar Yadav , ALSA Development Mailing List , bcm-kernel-feedback-list , Intel Graphics Development , intel-gvt-dev@lists.freedesktop.org, alpha , Linux ARM , linux-clk , Linux Crypto Mailing List , linux-edac@vger.kernel.org, Linux Fbdev development list , linux-hyperv@vger.kernel.org, linux-iio@vger.kernel.org, linux-leds , "open list:BROADCOM NVRAM DRIVER" , Parisc List , Linux PM list , linuxppc-dev , "open list:REMOTE PROCESSOR (REMOTEPROC) SUBSYSTEM" , Linux-Renesas , linux-s390 , scsi , Linux-sh list , linux-staging@lists.linux.dev, linux-tegra , linux-um , USB list , "open list:TENSILICA XTENSA PORT (xtensa)" , netdev , openipmi-developer@lists.sourceforge.net, rcu@vger.kernel.org, sparclinux , the arch/x86 maintainers , xen-devel@lists.xenproject.org Subject: Re: [PATCH v0 42/42] notifier: Return an error when callback is already registered Message-ID: References: <20211108101157.15189-1-bp@alien8.de> <20211108101157.15189-43-bp@alien8.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 08, 2021 at 04:25:47PM +0100, Geert Uytterhoeven wrote: > I'm not against returning proper errors codes. I'm against forcing > callers to check things that cannot fail and to add individual error > printing to each and every caller. If you're against checking things at the callers, then the registration function should be void. IOW, those APIs are not optimally designed atm. > Note that in other areas, we are moving in the other direction, > to a centralized printing of error messages, cfr. e.g. commit > 7723f4c5ecdb8d83 ("driver core: platform: Add an error message to > platform_get_irq*()"). Yes, thus my other idea to add a lower level __notifier_chain_register() to do the checking. I'll see if I can convert those notifier registration functions to return void, in the process. But let's see what the others think first. Thanks for taking the time. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette