Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933959Ab1FWX4B (ORCPT ); Thu, 23 Jun 2011 19:56:01 -0400 Received: from chilli.pcug.org.au ([203.10.76.44]:42532 "EHLO smtps.tip.net.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932752Ab1FWXz7 (ORCPT ); Thu, 23 Jun 2011 19:55:59 -0400 Date: Fri, 24 Jun 2011 09:55:42 +1000 From: Stephen Rothwell To: Ralf Baechle Cc: Greg Kroah-Hartman , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, David Howells , linux-m32r@ml.linux-m32r.org, linux-m32r-ja@ml.linux-m32r.org, linux-am33-list@redhat.com, Paul Mundt , linux-sh@vger.kernel.org, Chris Metcalf , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-arch@vger.kernel.org Subject: Re: [PATCH] STAGING: Comedi: Build only on arches providing PAGE_KERNEL_NOCACHE Message-Id: <20110624095542.e05698b4.sfr@canb.auug.org.au> In-Reply-To: <20110623114536.GA14011@linux-mips.org> References: <20110623114536.GA14011@linux-mips.org> X-Mailer: Sylpheed 3.1.1 (GTK+ 2.24.4; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg="PGP-SHA1"; boundary="Signature=_Fri__24_Jun_2011_09_55_42_+1000_t.eUmnEAvhaT_nyS" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2581 Lines: 67 --Signature=_Fri__24_Jun_2011_09_55_42_+1000_t.eUmnEAvhaT_nyS Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Ralf, On Thu, 23 Jun 2011 12:45:37 +0100 Ralf Baechle wrote: > > On architectures that don't define PAGE_KERNEL_NOCACHE, the Comedi driver= turns > into tragedy: >=20 > CC [M] drivers/staging/comedi/drivers.o > drivers/staging/comedi/drivers.c: In function =E2=80=98comedi_buf_alloc= =E2=80=99: > drivers/staging/comedi/drivers.c:505:41: error: =E2=80=98PAGE_KERNEL_NOCA= CHE=E2=80=99 undeclared (first use in this function) > drivers/staging/comedi/drivers.c:505:41: note: each undeclared identifier= is rep orted only once for each function it appears in > make[3]: *** [drivers/staging/comedi/drivers.o] Error 1 >=20 > Restrict the driver to only those architectures that define PAGE_KERNEL_N= OCACHE. >=20 > PAGE_KERNEL_NOCACHE is a kludge - some system architectures such as SGI I= P27 > are even uable to offer uncached operation - at least in the way an unwit= ting > driver might assume. I haven't looked in details how the driver is using > the area vmaped with PAGE_KERNEL_NOCACHE but maybe doing it XFS-style usi= ng > cached memory and the flush_kernel_vmap_range / invalidate_kernel_vmap_ra= nge > APIs in conjunction with the DMA API is a practical alternative. >=20 > Signed-off-by: Ralf Baechle Since Greg is on vacation, I will add this patch to my fixes tree in linux-next until a better fix comes along (if there is one). --=20 Cheers, Stephen Rothwell sfr@canb.auug.org.au http://www.canb.auug.org.au/~sfr/ --Signature=_Fri__24_Jun_2011_09_55_42_+1000_t.eUmnEAvhaT_nyS Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQEcBAEBAgAGBQJOA9J+AAoJEDMEi1NhKgbsFfkH/iXyBLKfo00uV5ym/QNH51Eb Xt8PeJ6xp1AevCgm94ei9jpIodgeyH7YVo1dJhyD6dI7Z8hPC6mTkcMytnM/ou5F +rAajf1T+qWBSJvft+1U1LZu4bae9zl054lkEnMx8Vwj5lhWALuI+NI92F8wNUwV M1aO1fyyOHiIDwNJZEn0iJ3XxCnwdm1MFNiujlqacapfoBSjpClBSS/S+RJLT7Wr SkmuMnI/6/RbknFR6gpyn3GnzjeTslUVUYBgS42rV9chaEWotT+spgpvpmYdyMEq rhucb+lutMAKr/kLpqONBoJS98zOCFH3PputZU13oB3TYGi8Iv9eeklFpqG9048= =OrXa -----END PGP SIGNATURE----- --Signature=_Fri__24_Jun_2011_09_55_42_+1000_t.eUmnEAvhaT_nyS-- -- 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/