From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751046AbWDMQIJ (ORCPT ); Thu, 13 Apr 2006 12:08:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751050AbWDMQII (ORCPT ); Thu, 13 Apr 2006 12:08:08 -0400 Received: from lixom.net ([66.141.50.11]:5283 "EHLO mail.lixom.net") by vger.kernel.org with ESMTP id S1751046AbWDMQIH (ORCPT ); Thu, 13 Apr 2006 12:08:07 -0400 Date: Thu, 13 Apr 2006 11:07:12 -0500 To: Benjamin Herrenschmidt Cc: Muli Ben-Yehuda , Olof Johansson , paulus@samba.org, linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [2/2] POWERPC: Lower threshold for DART enablement to 1GB, V2 Message-ID: <20060413160712.GG24769@pb15.lixom.net> References: <20060413020559.GC24769@pb15.lixom.net> <20060413022809.GD24769@pb15.lixom.net> <20060413025233.GE24769@pb15.lixom.net> <20060413064027.GH10412@granada.merseine.nu> <1144925149.4935.14.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1144925149.4935.14.camel@localhost.localdomain> User-Agent: Mutt/1.5.11 From: Olof Johansson Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 13, 2006 at 08:45:49PM +1000, Benjamin Herrenschmidt wrote: > On Thu, 2006-04-13 at 09:40 +0300, Muli Ben-Yehuda wrote: > > On Wed, Apr 12, 2006 at 09:52:33PM -0500, Olof Johansson wrote: > > > > > iommu=off can still be used for those who don't want to deal with the > > > overhead (and don't need it for any devices). > > > > I've been pondering walking the PCI bus before deciding to enable an > > IOMMU and checking each device's DMA mask. Is this something that you > > considered and rejected, or just something no one got around to doing? > > It would do the trick for airport cards in G5s.. a little bit of OF > walking to find the card. Walking the DT means we need to hardcode it on PCI IDs, since the Apple OF doesn't give the Airport device a logical name. It's probably easier to implement than walking PCI, but we'd need to maintain a table. My vote is for PCI walking, I'll give that a shot over the weekend. > It won't help with cardbus broadcom's but then, there is currently no G5 > with a cardbus adaptor that I know of :) It's possible I suppose to get > a pci<->cardbus adapter but I suppose in that case, we can ignore it ... Yep, that should be rare enough. -Olof