From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754097AbYIZOsE (ORCPT ); Fri, 26 Sep 2008 10:48:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752476AbYIZOry (ORCPT ); Fri, 26 Sep 2008 10:47:54 -0400 Received: from mtagate4.uk.ibm.com ([195.212.29.137]:33216 "EHLO mtagate4.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752770AbYIZOrx (ORCPT ); Fri, 26 Sep 2008 10:47:53 -0400 Date: Fri, 26 Sep 2008 17:47:08 +0300 From: Muli Ben-Yehuda To: Jeff Garzik Cc: Andres Freund , linux-kernel@vger.kernel.org Subject: Re: bad DMAR interaction with iwlagn and SATA Message-ID: <20080926144708.GD9118@il.ibm.com> References: <200809251511.20132.andres@anarazel.de> <48DC44D4.8000103@garzik.org> <200809260419.07713.andres@anarazel.de> <48DC4BC0.7090203@garzik.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48DC4BC0.7090203@garzik.org> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 25, 2008 at 10:41:04PM -0400, Jeff Garzik wrote: > Andres Freund wrote: >> Hi Jeff, >> On Friday 26 September 2008, you wrote in "Re: bad DMAR interaction with >> iwlagn and SATA": >>> Andres Freund wrote: >>>> sleeping I activated DMAR... >>>> .. >>>> Second: >>>> [ 2937.484251] DMAR:[DMA Read] Request device [00:1f.2] fault addr >>>> fffbf000 [ 2937.484255] DMAR:[fault reason 06] PTE Read access is not >>>> set >>>> [ 2937.484297] ata1.00: exception Emask 0x60 SAct 0x1 SErr 0x800 action >>>> 0x6 frozen >>>> [ 2937.484303] ata1.00: irq_stat 0x20000000, host bus error >>>> [ 2937.484309] ata1: SError: { HostInt } >>>> [ 2937.484319] ata1.00: cmd 61/08:00:c0:1d:6b/00:00:07:00:00/40 tag 0 >>>> ncq >>>> 4096 out >>>> [ 2937.484321] res 40/00:00:c0:1d:6b/00:00:07:00:00/40 Emask >>>> 0x60 (host bus error) >>> Ouch, a host bus error is serious nastiness... >> I only hit that with DMAR activated (hit it twice, different boots), so it >> seems to be related to that. Is there anything I can help to debug that? > > No idea about DMAR. On the ATA side, it pretty diagnoses itself as > you see here. Unfortunately, ATA controller is behaving exactly as > it should, when a major system error is thrown its way. The way to debug this is to figure out why device 00:1f.2 is trying to read from DMA address fffbf000 and does not have permission to do so. This could be indicative of a driver bug where it is programming the device to read from some buffer that has not been allocated through the DMA API and thus does not have a valid IOMMU mapping, or a hardware quirk where the device tries to read from memory without host involvement. The former is much more likely. Cheers, Muli -- The First Workshop on I/O Virtualization (WIOV '08) Dec 2008, San Diego, CA, http://www.usenix.org/wiov08/ xxx SYSTOR 2009---The Israeli Experimental Systems Conference http://www.haifa.il.ibm.com/conferences/systor2009/