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=-7.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 38C09C433E1 for ; Sun, 2 Aug 2020 14:54:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 19A8C2086A for ; Sun, 2 Aug 2020 14:54:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="h25uld9S" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726356AbgHBOyB (ORCPT ); Sun, 2 Aug 2020 10:54:01 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:31112 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726325AbgHBOxy (ORCPT ); Sun, 2 Aug 2020 10:53:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1596380033; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1kkoTewt7Fx4Q+2DDC1UGcR4JlqqtBcQK2oUP1r3rTc=; b=h25uld9SIfoj5VjErXtMPmIqvlXPAtJ9JBM59o8fHH2lQ1S+DyLmOlX51gMTheqs8+RYFB 9ufHZJCdVWjJaYwpalTcdDMcE3z82dp85ISkgHWnzjWf4A5Leg2ztBE7DWr4nwgqTn9jU+ 05CB8xgosBwf/jZez18nhURcbSzonbw= Received: from mail-qv1-f72.google.com (mail-qv1-f72.google.com [209.85.219.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-386-RFx__9KyPWGVkfEnhQKK2g-1; Sun, 02 Aug 2020 10:53:51 -0400 X-MC-Unique: RFx__9KyPWGVkfEnhQKK2g-1 Received: by mail-qv1-f72.google.com with SMTP id d30so4392243qve.5 for ; Sun, 02 Aug 2020 07:53:51 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=1kkoTewt7Fx4Q+2DDC1UGcR4JlqqtBcQK2oUP1r3rTc=; b=j4+RsANTCy6Kh2TxToZSAPRpdLCgpCQlUPpKdlZjZl6qWHkzjOgNBheIBKFY/j3FaW r6vrMSA902TxrX9zxE5yMwxYLQJXreSU5kpV+dhIoVN7LU5ipp6vE/nijFM9uKLn3iCe 8CiAL1q99mjy7HIscO0Vw090A19pdF1xVYKtPO5+Ldv0il85Nku1WnORMorgUn9UAHxB i34TcIJ3iwDYSmfjFeXzRoBS476YwtuCVFISQkmLn9NPJvlp4zbhJq7HOozIfl6I7iy5 bXGSyCiZRiZkIqCQTovhjz0Z7yfRP39x3c5+oIrOvDQ5KIh9lcw6d9qec3lM7Qjpt+3/ bWjA== X-Gm-Message-State: AOAM5316I0JYVXpYxYJigloNNWGyTTE1FpUv3ObpSKWOFtLmmRAW6XjA GzR+5rdpTQXDFL318/kjzYrCa6Ry4/XvJcCFviOlK/RhAituWUxL8pQO2nz/gE2OPS2MAgPVtgx 7uLJKyZZeFh1l4S1ewqor+b8= X-Received: by 2002:a0c:f007:: with SMTP id z7mr12711374qvk.53.1596380031293; Sun, 02 Aug 2020 07:53:51 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzsaj772ZR8xxDSmSbCv1i3DbzhNyKSnnIAtdh3ZvECGhzafck69cLoHqLTgfamrb5jJgzXtg== X-Received: by 2002:a0c:f007:: with SMTP id z7mr12711349qvk.53.1596380031093; Sun, 02 Aug 2020 07:53:51 -0700 (PDT) Received: from trix.remote.csb (075-142-250-213.res.spectrum.com. [75.142.250.213]) by smtp.gmail.com with ESMTPSA id t127sm16326265qkc.100.2020.08.02.07.53.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 02 Aug 2020 07:53:50 -0700 (PDT) Subject: Re: [RFC PATCH 00/17] Drop uses of pci_read_config_*() return value To: Borislav Petkov , "Saheed O. Bolarinwa" Cc: helgaas@kernel.org, Kalle Valo , "David S. Miller" , Jakub Kicinski , Wolfgang Grandegger , Marc Kleine-Budde , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Joerg Roedel , bjorn@helgaas.com, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-mtd@lists.infradead.org, iommu@lists.linux-foundation.org, linux-rdma@vger.kernel.org, linux-ide@vger.kernel.org, linux-i2c@vger.kernel.org, linux-hwmon@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-gpio@vger.kernel.org, linux-fpga@vger.kernel.org, linux-edac@vger.kernel.org, dmaengine@vger.kernel.org, linux-crypto@vger.kernel.org, linux-atm-general@lists.sourceforge.net References: <20200801112446.149549-1-refactormyself@gmail.com> <20200801125657.GA25391@nazgul.tnic> From: Tom Rix Message-ID: <6ecce8f3-350a-b5d5-82c9-4609f2298e61@redhat.com> Date: Sun, 2 Aug 2020 07:53:46 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200801125657.GA25391@nazgul.tnic> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org On 8/1/20 5:56 AM, Borislav Petkov wrote: > On Sat, Aug 01, 2020 at 01:24:29PM +0200, Saheed O. Bolarinwa wrote: >> The return value of pci_read_config_*() may not indicate a device error. >> However, the value read by these functions is more likely to indicate >> this kind of error. This presents two overlapping ways of reporting >> errors and complicates error checking. > So why isn't the *value check done in the pci_read_config_* functions > instead of touching gazillion callers? > > For example, pci_conf{1,2}_read() could check whether the u32 *value it > just read depending on the access method, whether that value is ~0 and > return proper PCIBIOS_ error in that case. > > The check you're replicating > > if (val32 == (u32)~0) > > everywhere, instead, is just ugly and tests a naked value ~0 which > doesn't mean anything... > I agree, if there is a change, it should be in the pci_read_* functions. Anything returning void should not fail and likely future users of the proposed change will not do the extra checks. Tom