From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932356Ab0I3TFo (ORCPT ); Thu, 30 Sep 2010 15:05:44 -0400 Received: from cavan.codon.org.uk ([93.93.128.6]:56297 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932094Ab0I3TFm (ORCPT ); Thu, 30 Sep 2010 15:05:42 -0400 Date: Thu, 30 Sep 2010 20:05:36 +0100 From: Matthew Garrett To: Joerg Roedel Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, joerg.roedel@amd.com, jbarnes@virtuousgeek.org Subject: Re: [PATCH] pci: Reenable the AMD IOMMU if it's mysteriously vanished over suspend Message-ID: <20100930190536.GA18845@srcf.ucam.org> References: <1285861108-24122-1-git-send-email-mjg@redhat.com> <20100930173945.GA16596@srcf.ucam.org> <20100930184301.GP15338@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100930184301.GP15338@8bytes.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mjg59@cavan.codon.org.uk X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 30, 2010 at 08:43:01PM +0200, Joerg Roedel wrote: > Enabling the IOMMU device is only part of what the BIOS is supposed to > do to get the IOMMU ready for the OS. A handful of registers in the > config space of the device and the IOMMU MMIO region must also be > restored. Thats the simple part. The IOMMU device also spans two > indirect register spaces to configure the IOMMU caches. I have no idea > yet how this need to be configured. The plan is definitly to > work-around a missing IOMMU device in the IOMMU driver. But I am still > talking to some people to find out what exactly must be done, especially > with the indirect register spaces. Chapter 8 of the register setup guide seems to have something on this - I'll try saving and restoring all of the setup it performs to see if it improves things. -- Matthew Garrett | mjg59@srcf.ucam.org