From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726471AbgHAM4q (ORCPT ); Sat, 1 Aug 2020 08:56:46 -0400 Date: Sat, 1 Aug 2020 14:56:57 +0200 From: Borislav Petkov Subject: Re: [RFC PATCH 00/17] Drop uses of pci_read_config_*() return value Message-ID: <20200801125657.GA25391@nazgul.tnic> References: <20200801112446.149549-1-refactormyself@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200801112446.149549-1-refactormyself@gmail.com> Sender: linux-fpga-owner@vger.kernel.org List-Id: linux-fpga@vger.kernel.org To: "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 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... -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette