From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:38558 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750736AbcBEB5k (ORCPT ); Thu, 4 Feb 2016 20:57:40 -0500 Date: Thu, 4 Feb 2016 19:57:34 -0600 From: Bjorn Helgaas To: Andi Kleen Cc: Andi Kleen , bhelgaas@google.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH] x86, pci: Add quirk for unsizeable Broadwell EP bar Message-ID: <20160205015734.GA29929@localhost> References: <1452896279-22034-1-git-send-email-andi@firstfloor.org> <20160204174155.GB19957@localhost> <20160204185442.GA4875@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20160204185442.GA4875@tassilo.jf.intel.com> Sender: linux-pci-owner@vger.kernel.org List-ID: On Thu, Feb 04, 2016 at 10:54:42AM -0800, Andi Kleen wrote: > > It sounds like these devices have some device-specific register where > > BAR 0 is supposed to be? Setting IORESOURCE_PCI_FIXED doesn't seem > > like the right solution to me. Even if we set that, the core still > > There is no actually functional register on these locations that has any side > effects. > > > believes this resource corresponds to some address space consumed by > > the device. I think we will still try to size the BAR and decode its > > type. I think it will still show up via lspci. That's all > > meaningless. > > But would actually anything use it? You mean, would anything actually use the lspci output? I don't know, but why would we want it to print garbage? And the kernel certainly uses the struct resource. Setting IORESOURCE_PCI_FIXED is not a way of saying "please ignore this resource." Bjorn