Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755082AbYJ2Uwk (ORCPT ); Wed, 29 Oct 2008 16:52:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754709AbYJ2Uw2 (ORCPT ); Wed, 29 Oct 2008 16:52:28 -0400 Received: from g4t0015.houston.hp.com ([15.201.24.18]:27248 "EHLO g4t0015.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753165AbYJ2Uw1 (ORCPT ); Wed, 29 Oct 2008 16:52:27 -0400 Subject: Re: [PATCH] disable CPU side GART accesses From: Bob Montgomery Reply-To: bob.montgomery@hp.com To: Yinghai Lu Cc: Ingo Molnar , "linux-kernel@vger.kernel.org" , "vojtech@suse.cz" , Linus Torvalds , "chandru@in.ibm.com" , Joerg Roedel , FUJITA Tomonori , Jesse Barnes , Pavel Machek , Andi Kleen , Dave Jones In-Reply-To: <4906495B.1060506@kernel.org> References: <1224107317.2215.238.camel@amd.troyhebe> <20081015234842.GA10999@elte.hu> <1225147341.2215.401.camel@amd.troyhebe> <4906495B.1060506@kernel.org> Content-Type: text/plain; charset=UTF-8 Organization: Contractor at HP Date: Wed, 29 Oct 2008 14:52:44 -0600 Message-Id: <1225313564.3428.14.camel@amd.troyhebe> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 Content-Transfer-Encoding: 8bit X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1464 Lines: 46 On Mon, 2008-10-27 at 23:06 +0000, Yinghai Lu wrote: > Bob Montgomery wrote: > > On Wed, 2008-10-15 at 23:48 +0000, Ingo Molnar wrote: > >> (Cc:-ed the GART folks.) > > > > Are there any objections to this patch? The problem has been reproduced > > in 2.6.18 and 2.6.27, so existing changes in the gart code have not > > addressed it. > > better to have someone with amd system + 8g ram + agp adapter to verify it... > > YH Good idea. I don't think HP made a system with opteron and agp, so I haven't found a system here to test. But I did see that there have been non-HP motherboards from several years ago that advertised opteron with agp. Anyone running that type of system? The other question is whether AGP graphics on linux for amd64 ever expected host translation to work, since setting DisGartCpu is turning off host translation. I saw this in the AGP 3.0 spec (hopeful, but inconclusive): "8. The Core-logic is not required by the AGP specification to translate accesses directed to the AGP aperture by a host processor – termed host translation. Portable AGP3.0 software should not rely upon the existence of host translation." Any advice from graphics experts? Bob Montgomery -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/