Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932742Ab0AFUS3 (ORCPT ); Wed, 6 Jan 2010 15:18:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932580Ab0AFUS2 (ORCPT ); Wed, 6 Jan 2010 15:18:28 -0500 Received: from g4t0017.houston.hp.com ([15.201.24.20]:7974 "EHLO g4t0017.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932552Ab0AFUS1 (ORCPT ); Wed, 6 Jan 2010 15:18:27 -0500 From: Bjorn Helgaas To: Alex Brooks Subject: Re: BAR 0: can't allocate resource Date: Wed, 6 Jan 2010 13:19:54 -0700 User-Agent: KMail/1.12.2 (Linux/2.6.31-16-generic; KDE/4.3.2; x86_64; ; ) Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org References: <201001061305.31635.a.brooks@marathon-robotics.com> <201001061316.21744.a.brooks@marathon-robotics.com> In-Reply-To: <201001061316.21744.a.brooks@marathon-robotics.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201001061319.54436.bjorn.helgaas@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1408 Lines: 32 On Tuesday 05 January 2010 07:16:21 pm Alex Brooks wrote: > > I don't see any indication that this is a software problem (I know > > nothing about PC/104, so let me know if you disagree, and why). > > I don't have a smoking gun that points at software, it was just my guess > based on: > a) all the pieces of hardware work in certain combinations > b) there's a nasty-looking error message in dmesg You mentioned two messages. Here's the first: PCI: BIOS Bug: MCFG area at e0000000 is not reserved in ACPI motherboard resources PCI: Not using MMCONFIG. and the second: PCI: Cannot allocate resource region 0 of device 0000:01:04.0 PCI: Error while updating region 0000:01:04.0/0 (feb00002 != 00000000) The "Error while updating region" message is because we wrote something to a BAR, read it back, and they didn't match. I suppose this could be some kind of config space problem related to the fact that we're not using MMCONFIG. Can you try removing the MCFG reservation check, so we do try to use MMCONFIG? If you do this on a current kernel, we'll also get a little more debug output about the subsequent resource allocation failure. 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/