Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753726AbXJ2UNe (ORCPT ); Mon, 29 Oct 2007 16:13:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751549AbXJ2UN0 (ORCPT ); Mon, 29 Oct 2007 16:13:26 -0400 Received: from home.keithp.com ([63.227.221.253]:4046 "EHLO keithp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751511AbXJ2UNZ (ORCPT ); Mon, 29 Oct 2007 16:13:25 -0400 Subject: Re: [RFC] AGP initial support for chipset flushing.. From: Keith Packard To: Jesse Barnes Cc: keithp@keithp.com, dri-devel@lists.sourceforge.net, Dave Airlie , linux-kernel@vger.kernel.org, dri-devel@lists.sourceforge.net In-Reply-To: <200710291247.24791.jesse.barnes@intel.com> References: <200710291247.24791.jesse.barnes@intel.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-8xI0ekkhwxh9IEjF1EsV" Date: Mon, 29 Oct 2007 13:12:58 -0700 Message-Id: <1193688778.4723.35.camel@koto.keithp.com> Mime-Version: 1.0 X-Mailer: Evolution 2.12.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1596 Lines: 51 --=-8xI0ekkhwxh9IEjF1EsV Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Mon, 2007-10-29 at 12:47 -0700, Jesse Barnes wrote: > In this case, we're performing basically a dma_sync*(...DMA_TO_DEVICE)=20 > right? But this is just for the GPU; every other DMA device in the system is cache-coherent. > Can we be sure that a single flush is sufficient? Is there any=20 > window between when we flush and when we start accessing memory with=20 > the device that we could get into more caching trouble? An uncached write to this page will not complete until the buffers are completely flushed. > Looks reasonable, I'm not sure we can do much better. The only concern=20 > I have is that allocating some more PCI space like that may end up=20 > clobbering some *other* hidden BIOS mapping, but there's not a whole=20 > lot we can do about that. This isn't a hidden mapping; the i965 doesn't allocate space for it in the BIOS. --=20 keith.packard@intel.com --=-8xI0ekkhwxh9IEjF1EsV Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQBHJj7KQp8BWwlsTdMRAjBVAKCG9eVDGR2612BjtJNTCvVJlmFGoQCgmpCn 927OcNuGsJYFRS0o/iblMEc= =U0YV -----END PGP SIGNATURE----- --=-8xI0ekkhwxh9IEjF1EsV-- - 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/