From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753095Ab1KOEb5 (ORCPT ); Mon, 14 Nov 2011 23:31:57 -0500 Received: from mail-gx0-f174.google.com ([209.85.161.174]:57749 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751228Ab1KOEb4 (ORCPT ); Mon, 14 Nov 2011 23:31:56 -0500 Message-ID: <4EC1EB39.1080705@gmail.com> Date: Mon, 14 Nov 2011 22:31:53 -0600 From: Robert Hancock User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111108 Thunderbird/8.0 MIME-Version: 1.0 To: Arnd Hannemann CC: linux-kernel@vger.kernel.org, dwmw2@infradead.org, iommu@lists.linux-foundation.org Subject: Re: 3.2rc1: bootup fails: DRHD: handling fault status reg 2 References: <4EC19738.8050007@arndnet.de> <4EC1B80D.5000102@arndnet.de> In-Reply-To: <4EC1B80D.5000102@arndnet.de> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/14/2011 06:53 PM, Arnd Hannemann wrote: > Hi, > > Am 14.11.2011 23:33, schrieb Arnd Hannemann: > >> when trying to boot kernel 3.2rc1 on my thinkpad t510 I get an endless loop of errors: >> >> DRHD: handling fault status reg 2 >> DMAR: [DMA Read] Request device [0d:00.0] fault addr fffff000 >> DMAR: [fault reason 02] Present bit in context entry is clear >> >> screenshot can be found here: >> http://arndnet.de/lkml/screenshot3.2rc1.jpg >> >> kernel 3.1.1 is booting up flawlessly. > > I must have inadvertently enabled CONFIG_INTEL_IOMMU_DEFAULT_ON in my config > for 3.2-rc1. > > With disabled CONFIG_INTEL_IOMMU_DEFAULT_ON my thinkpad boots up again. > Not sure if this is expected? No, that's not supposed to happen. Can you post the output of "lspci -vv"? Apparently that device 0d:00.0 is generating unexpected DMA accesses for some reason.