From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f170.google.com ([209.85.213.170]:42978 "EHLO mail-ig0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754920AbaLDWZi (ORCPT ); Thu, 4 Dec 2014 17:25:38 -0500 Received: by mail-ig0-f170.google.com with SMTP id r2so20571836igi.1 for ; Thu, 04 Dec 2014 14:25:37 -0800 (PST) Date: Thu, 4 Dec 2014 15:25:34 -0700 From: Bjorn Helgaas To: Yinghai Lu Cc: "linux-pci@vger.kernel.org" , Alexey Voronkov , David Airlie , Saifi Khan , Alex Deucher , Marek =?iso-8859-1?Q?Kord=EDk?= Subject: Re: Regression: bug 85491: radeon 0000:01:00.0: Fatal error during GPU init Message-ID: <20141204222534.GA2911@google.com> References: <20141204161506.GA2501@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-pci-owner@vger.kernel.org List-ID: On Thu, Dec 04, 2014 at 02:15:14PM -0800, Yinghai Lu wrote: > On Thu, Dec 4, 2014 at 8:15 AM, Bjorn Helgaas wrote: > > On Wed, Dec 03, 2014 at 05:41:32PM -0800, Yinghai Lu wrote: > >> On Wed, Dec 3, 2014 at 5:38 PM, Yinghai Lu wrote: > >> > On Wed, Dec 3, 2014 at 2:15 PM, Bjorn Helgaas wrote: > >> >> There's a bugzilla for this, so this email is to make the bugzilla > >> >> more discoverable and to have a more public discussion about it. > >> >> > >> >> https://bugzilla.kernel.org/show_bug.cgi?id=85491 > >> >> > >> >> I think this regression is caused by 5b28541552ef ("PCI: Restrict > >> >> 64-bit prefetchable bridge windows to 64-bit resources"). These dmesg > >> >> fragments are from v3.16, which doesn't work: > >> >> > >> >> pci_bus 0000:00: root bus resource [mem 0xc0000000-0xffffffff] > >> >> > >> >> pci 0000:00:01.0: PCI bridge to [bus 01] > >> >> pci 0000:00:01.0: bridge window [io 0x8000-0xafff] > >> >> pci 0000:00:01.0: bridge window [mem 0xfdf00000-0xfdffffff] > >> >> pci 0000:00:01.0: bridge window [mem 0xbdf00000-0xddefffff 64bit > >> >> pref] <-- outside host bridge window > >> >> > >> >> pci 0000:01:00.0: reg 0x10: [mem 0xc0000000-0xcfffffff pref] > >> >> pci 0000:01:00.0: reg 0x14: [io 0xa000-0xa0ff] > >> >> pci 0000:01:00.0: reg 0x18: [mem 0xfdff0000-0xfdffffff] > >> >> pci 0000:01:00.0: reg 0x30: [mem 0xfdfc0000-0xfdfdffff pref] > >> >> > >> >> pci 0000:00:01.0: can't claim BAR 15 [mem 0xbdf00000-0xddefffff > >> >> 64bit pref]: no compatible bridge window > >> >> pci 0000:01:00.0: can't claim BAR 0 [mem 0xc0000000-0xcfffffff > >> >> pref]: no compatible bridge window > >> > > >> > Looks like we wrong type checking from parent resource searching. > > > > I don't understand what you're trying to say, but I don't think the "no > > compatible bridge window" problem is related to resource types. I think > > it's because the 00:01.0 window at [mem 0xbdf00000-0xddefffff] starts > > before the [mem 0xc0000000-0xffffffff] host bridge window. > > on this system _CRS is not used. Oh, sorry, I didn't notice that Zermond's system doesn't use _CRS. I had been looking at the logs from Marek, and we *do* use _CRS there. On Zermond's machine we do still have the e820 code that figures out this: e820: [mem 0xc0000000-0xfedfffff] available for PCI devices I think we could at least clamp the default host bridge window ([mem 0x00000000-0xfffffffff]) to that. Bjorn