Return-path: Received: from he.sipsolutions.net ([78.46.109.217]:56190 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758595Ab1FVSyF (ORCPT ); Wed, 22 Jun 2011 14:54:05 -0400 Subject: Re: [3.0 regression] DMAR faults in iwlagn From: Johannes Berg To: Andrew Lutomirski Cc: ilw@linux.intel.com, linux-wireless@vger.kernel.org In-Reply-To: (sfid-20110620_204449_827132_DD43A304) References: (sfid-20110620_204449_827132_DD43A304) Content-Type: text/plain; charset="UTF-8" Date: Wed, 22 Jun 2011 20:54:00 +0200 Message-ID: <1308768840.29571.23.camel@jlt3.sipsolutions.net> (sfid-20110622_205409_792141_54533F58) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, 2011-06-20 at 14:44 -0400, Andrew Lutomirski wrote: > On 3.0-git today, I get: > > [ 40.142872] DRHD: handling fault status reg 2 > [ 40.142892] DMAR:[DMA Write] Request device [03:00.0] fault addr ffe38000 > [ 40.142896] DMAR:[fault reason 05] PTE Write access is not set Reinette also said she saw this and kindly let me use one of her systems to track it down. It looks like this: iwl_enqueue_hcmd : mapping 1 at ffce2000 dmar_fault : DMAR:[DMA Write] Request device [02:00.0] fault addr ffce2000 DMAR:[fault reason 05] PTE Write access is not set So it's really due to my command changes, and the device is attempting to write back to at least some commands. I see it doing that for PHY calibration data, but I think on Reinette's system it was probably for other commands as well since it happened a lot... I think we have to map commands BIDI, even if I don't really understand why. johannes