From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755315Ab0EVMMR (ORCPT ); Sat, 22 May 2010 08:12:17 -0400 Received: from palinux.external.hp.com ([192.25.206.14]:48804 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754153Ab0EVMMN (ORCPT ); Sat, 22 May 2010 08:12:13 -0400 Date: Sat, 22 May 2010 06:12:12 -0600 From: Matthew Wilcox To: Stefan Richter Cc: linux-pci@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, David Woodhouse Subject: Re: DMAR:[fault reason 02] Present bit in context entry is clear (firewire-ohci) Message-ID: <20100522121212.GQ10452@parisc-linux.org> References: <4BF7B147.9020502@s5r6.in-berlin.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4BF7B147.9020502@s5r6.in-berlin.de> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 22, 2010 at 12:26:15PM +0200, Stefan Richter wrote: > Hi, > > I came across a report of the subject message. What does it mean; what > type of bug should be look for? > > https://bugzilla.redhat.com/show_bug.cgi?id=587178 > >>> > firewire_ohci 0000:04:00.4: PCI INT C -> GSI 16 (level, low) -> IRQ 16 > firewire_ohci 0000:04:00.4: setting latency timer to 64 > firewire_ohci: Added fw-ohci device 0000:04:00.4, OHCI version 1.0 > DRHD: handling fault status reg 2 > DMAR:[DMA Read] Request device [04:00.0] fault addr fffff000 > DMAR:[fault reason 02] Present bit in context entry is clear > DMAR:[DMA Read] Request device [04:00.0] fault addr fffff000 > DMAR:[fault reason 02] Present bit in context entry is clear > DMAR:[DMA Read] Request device [04:00.0] fault addr fffff000 > DMAR:[fault reason 02] Present bit in context entry is clear > <<< > > The log sounds as if this happens during from-device DMA of 04:00.4 into > a consistent buffer, yet the fault is logged for device 04:00.0. The > log is from a Dell M4500. The devices are, according to a web search, > 04:00.0 CardBus bridge [0607]: Ricoh Co Ltd Device [1180:e476] (rev 02) > 04:00.4 FireWire (IEEE 1394) [0c00]: Ricoh Co Ltd Device [1180:e832] > (rev 03) (prog-if 10) I would guess that the DMAR can't distinguish between the different devices behind the Cardbus bridge. Adding Dave Woodhouse. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."