Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263622AbUCUJxH (ORCPT ); Sun, 21 Mar 2004 04:53:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263623AbUCUJxH (ORCPT ); Sun, 21 Mar 2004 04:53:07 -0500 Received: from mx1.redhat.com ([66.187.233.31]:36843 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S263622AbUCUJxD (ORCPT ); Sun, 21 Mar 2004 04:53:03 -0500 Subject: Re: can device drivers return non-ram via vm_ops->nopage? From: Arjan van de Ven Reply-To: arjanv@redhat.com To: Russell King Cc: William Lee Irwin III , Jaroslav Kysela , Linus Torvalds , LKML In-Reply-To: <20040320235445.B24744@flint.arm.linux.org.uk> References: <20040320133025.GH9009@dualathlon.random> <20040320144022.GC2045@holomorphy.com> <20040320150621.GO9009@dualathlon.random> <20040320154419.A6726@flint.arm.linux.org.uk> <20040320160911.B6726@flint.arm.linux.org.uk> <20040320222341.J6726@flint.arm.linux.org.uk> <20040320224518.GQ2045@holomorphy.com> <20040320235445.B24744@flint.arm.linux.org.uk> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-zRNBk9vpxNtFyjDZzajk" Organization: Red Hat, Inc. Message-Id: <1079862762.5295.6.camel@laptop.fenrus.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 (1.4.5-7) Date: Sun, 21 Mar 2004 10:52:43 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1410 Lines: 41 --=-zRNBk9vpxNtFyjDZzajk Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Sun, 2004-03-21 at 00:54, Russell King wrote: > On Sat, Mar 20, 2004 at 02:45:18PM -0800, William Lee Irwin III wrote: > > Is there any possibility of an extension to remap_area_pages() that > > could resolve this? I can't say I fully understood and/or remember > > the issue with it that you pointed out. >=20 > The issues are: >=20 > 1. ALSA wants to mmap the buffer used to transfer data to/from the > card into user space. This buffer may be direct-mapped RAM, > memory allocated via dma_alloc_coherent(), an on-device buffer, > or anything else. fwiw an ideal DRI/DRM driver would do the same with the video cards ringbuffer so the problem isn't unique to alsa, it's a generic issue. --=-zRNBk9vpxNtFyjDZzajk Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (GNU/Linux) iD8DBQBAXWXqxULwo51rQBIRAocUAJ968lq4qmQmBh9L0mKOOlEhYhPKNwCfSqdn kf+Cbklza8rEKvDbZkOmJGM= =Slyb -----END PGP SIGNATURE----- --=-zRNBk9vpxNtFyjDZzajk-- - 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/