Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753539Ab0DZPmA (ORCPT ); Mon, 26 Apr 2010 11:42:00 -0400 Received: from g6t0186.atlanta.hp.com ([15.193.32.63]:44029 "EHLO g6t0186.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752950Ab0DZPl6 (ORCPT ); Mon, 26 Apr 2010 11:41:58 -0400 From: Bjorn Helgaas To: "R. Andrew Bailey" Subject: Re: [PATCH] x86/PCI: never allocate PCI MMIO resources below BIOS_END Date: Mon, 26 Apr 2010 09:40:48 -0600 User-Agent: KMail/1.9.10 Cc: Andy Isaacson , Yinghai , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , guenter.roeck@ericsson.com, Linus Torvalds , "linux-pci@vger.kernel.org" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , Thomas Renninger , yaneti@declera.com References: <4BC4E55B.7000103@oracle.com> <201004231705.25659.bjorn.helgaas@hp.com> <20100426125032.GA1623@akamai.com> In-Reply-To: <20100426125032.GA1623@akamai.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <201004260940.52478.bjorn.helgaas@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2200 Lines: 45 On Monday 26 April 2010 06:50:32 am R. Andrew Bailey wrote: > On 23/04/10 17:05 -0600, Bjorn Helgaas wrote: > >On Wednesday 21 April 2010 01:31:20 pm Andy Isaacson wrote: > >Would you guys (Andy & Andy, what a coincidence :-)) mind giving > >it a try? This is intended to work on top of current upstream, > >with no other patches required. > > > Good news- that solved it. I tried Yinghai's patches saturday to no > avail (sorry it took me so long to get back to you, I was about 5 bios > revisions behind on this machine and wanted to update it before I > tried any more tests). Great, thanks for testing this! The only problem here is that we changed two things at once -- the BIOS and the patch, and we need to figure out which change fixed the problem. I want Linux to work correctly even on the old BIOS, on the theory that "if Windows works, Linux should work, too." Changing a BIOS is relatively risky, and it's not something I want users to have to diagnose and deal with. If we're lucky, the kernel without the patch will still fail on the updated BIOS. If the pre-patch kernel fails and the post-patch kernel works, and you can attach the entire dmesg log of the post-patch kernel to the bugzilla, we should be able to see Linux making more sensible BAR assignments when working around the BIOS bug. Then we can be pretty confident that my patch fixed the problem. If the pre-patch kernel works on the updated BIOS, that means one of the BIOS updates fixed the BIOS bug, and we didn't actually exercise my patch at all. If that's the case, we'll have to wait for a report from the other Andy. (Or you could temporarily down-grade your BIOS to the original version you had. But I don't know whether that's even possible... it probably depends on the BIOS update tools.) Thanks again for all your help. All progress in Linux depends on early adopters like you who are willing to test kernels and help work through issues :-) 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/