From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 25 Nov 2009 01:31:44 +0100 (CET) Received: from ozlabs.org ([203.10.76.45]:39171 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S1493633AbZKYAbk (ORCPT ); Wed, 25 Nov 2009 01:31:40 +0100 Received: from [127.0.0.1] (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id CF4DFB6F0A; Wed, 25 Nov 2009 11:31:34 +1100 (EST) Subject: Re: Time to make PCI_MSI default y ? From: Michael Ellerman Reply-To: michael@ellerman.id.au To: Benjamin Herrenschmidt Cc: Ralf Baechle , linux-pci , linux@arm.linux.org.uk, "tony.luck" , fenghua.yu@intel.com, "David S.Miller" , Thomas Gleixner , mingo@redhat.com, Peter Anvin , linux-mips@linux-mips.org, David Daney In-Reply-To: <1259096952.16367.134.camel@pasglop> References: <1259030388.20596.5.camel@concordia> <20091124125309.GB5749@linux-mips.org> <1259096952.16367.134.camel@pasglop> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-RVz3yeQHAyvYEEUvnxfu" Date: Wed, 25 Nov 2009 11:31:34 +1100 Message-ID: <1259109094.4017.5.camel@concordia> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 25117 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: michael@ellerman.id.au Precedence: bulk X-list: linux-mips --=-RVz3yeQHAyvYEEUvnxfu Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2009-11-25 at 08:09 +1100, Benjamin Herrenschmidt wrote: > On Tue, 2009-11-24 at 12:53 +0000, Ralf Baechle wrote: > > On Tue, Nov 24, 2009 at 01:39:48PM +1100, Michael Ellerman wrote: > >=20 > > > Having just hit a build-break caused by a distro building with > > > PCI_MSI=3Dn, I set out to make it default y for powerpc. Unfortunatel= y > > > that's not possible, because it's in drivers/pci/Kconfig. > > >=20 > > > So is it time to make it default y for everyone? It seems to me havin= g > > > it off is more likely to cause problems than having it on these days, > > > though I'm not sure if that is true for all archs. > > >=20 > > > An arch that really didn't want it default y could conditionally sele= ct > > > ARCH_SUPPORTS_MSI, like x86 does already. > >=20 > > On MIPS the age of MSI only recently started; once single platform (Cav= ium) > > out of all the many uses it. Cavium does a "select ARCH_SUPPORTS_MSI" = but > > not "select PCI_MSI" because not all platform variants actually have PC= I. > >=20 > > We should not give a user a chance to select something wrong in kconfi= g > > thus automatically as many options for a platform as possible is a good > > thing - after all the kconfig dialog for any given platfrom has become > > painfully long. And we really should have to avoid users having to kno= w > > that the Frobnic 2000 they're trying to upgrade the kernel for requires > > MSI to work ... >=20 > Still... select has nasty issues. I think default y is fine here. For > platforms that don't need it, make sure their defconfigs don't have it > set... >=20 > Or maybe default y if (X86 || PPC) Oh yeah I forgot we could do that. So we could either do that, or add a ARCH_MSI_DEFAULT and use that as the if condition. If people really care. cheers --=-RVz3yeQHAyvYEEUvnxfu Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAksMeuIACgkQdSjSd0sB4dJDdwCgnhD9XrrLpl3p2ixnZewInlnO 2rMAn2rFyVmTxDIznkutZov0DJUA0usN =gF6g -----END PGP SIGNATURE----- --=-RVz3yeQHAyvYEEUvnxfu--