Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757708AbZD0ToW (ORCPT ); Mon, 27 Apr 2009 15:44:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756684AbZD0ToM (ORCPT ); Mon, 27 Apr 2009 15:44:12 -0400 Received: from g1t0026.austin.hp.com ([15.216.28.33]:19145 "EHLO g1t0026.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754899AbZD0ToL convert rfc822-to-8bit (ORCPT ); Mon, 27 Apr 2009 15:44:11 -0400 From: Bjorn Helgaas To: Yinghai Lu Subject: Re: [PATCH] x86/pci: do assign root bus res if _CRS is used Date: Mon, 27 Apr 2009 13:44:01 -0600 User-Agent: KMail/1.9.10 Cc: Jesse Barnes , Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner , "linux-kernel@vger.kernel.org" , linux-pci@vger.kernel.org, Gary Hade , Alex Chiang , linux-acpi@vger.kernel.org, Matthew Wilcox References: <49ED22EC.2040204@kernel.org> In-Reply-To: <49ED22EC.2040204@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline Message-Id: <200904271344.04099.bjorn.helgaas@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1563 Lines: 45 On Monday 20 April 2009 07:35:40 pm Yinghai Lu wrote: > it wil be overwriten later if _CRS is used, so don't bother to set it. > > [ Impact: cleanup ] > > Signed-off-by: Yinghai Lu > > --- > arch/x86/pci/amd_bus.c | 4 ++++ > 1 file changed, 4 insertions(+) > > Index: linux-2.6/arch/x86/pci/amd_bus.c > =================================================================== > --- linux-2.6.orig/arch/x86/pci/amd_bus.c > +++ linux-2.6/arch/x86/pci/amd_bus.c > @@ -100,6 +100,10 @@ void x86_pci_root_bus_res_quirks(struct > int j; > struct pci_root_info *info; > > + /* don't go for it if _CRS is used */ > + if (pci_probe & PCI_USE__CRS) > + return; > + > /* if only one root bus, don't need to anything */ > if (pci_root_num < 2) > return; This isn't a comment on this patch per se. I am concerned about the fact that "pci=use_crs" is not the default. >From the changelog of 62f420f8282, it sounds like you have to boot an IBM x3850 with "pci=use_crs" to make hot-plug work, even though ACPI tells us everything we need to know. That's backwards. We shouldn't need an option to tell Linux that the firmware is trustworthy. We should have an option to *ignore* it for the times when we trip over something broken and haven't figured out a way to work around it yet. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/