From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754832AbbIID01 (ORCPT ); Tue, 8 Sep 2015 23:26:27 -0400 Received: from mail-pa0-f51.google.com ([209.85.220.51]:34197 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754623AbbIID0I (ORCPT ); Tue, 8 Sep 2015 23:26:08 -0400 Date: Wed, 9 Sep 2015 11:25:48 +0800 From: Boqun Feng To: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Arnd Bergmann , Benjamin Herrenschmidt , Paul Mackerras , Olof Johansson , Geoff Levand Subject: Re: [PATCH] powerpc: Kconfig: remove BE-only platforms from LE kernel build Message-ID: <20150909032548.GA18626@fixme-laptop.cn.ibm.com> References: <1441583880-17824-1-git-send-email-boqun.feng@gmail.com> <1441765604.7854.6.camel@ellerman.id.au> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="GvXjxJ+pjyke8COw" Content-Disposition: inline In-Reply-To: <1441765604.7854.6.camel@ellerman.id.au> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --GvXjxJ+pjyke8COw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Michael, On Wed, Sep 09, 2015 at 12:26:44PM +1000, Michael Ellerman wrote: > On Mon, 2015-09-07 at 07:58 +0800, Boqun Feng wrote: > > diff --git a/arch/powerpc/platforms/cell/Kconfig b/arch/powerpc/platfor= ms/cell/Kconfig > > index 2f23133..808a904 100644 > > --- a/arch/powerpc/platforms/cell/Kconfig > > +++ b/arch/powerpc/platforms/cell/Kconfig > > @@ -25,7 +25,7 @@ config PPC_CELL_NATIVE > > =20 > > config PPC_IBM_CELL_BLADE > > bool "IBM Cell Blade" > > - depends on PPC64 && PPC_BOOK3S > > + depends on PPC64 && PPC_BOOK3S && CPU_BIG_ENDIAN >=20 > We end up saying this five times. >=20 > We already have PPC_BOOK3S_64 which captures the first two conditions, sh= ould > we add a PPC_BOOK3S_64_BE which expresses it all? >=20 I'm not sure whether this is worth.. IMO, we add a config option only if 1. we can use this config somewhere in the code, for example, "#ifdef CONFIG_XXX" or 2. we want to offer a option for users to choose. PPC_BOOK3S_64_BE satisfies neither condition. Further more, CONFIG_PPC64, CONFIG_PPC_BOOK3S and CONFIG_CPU_BIG_ENDIAN all are used in some #ifdefs in current code. As a newbie of kernel, I'm happy to get some knowledge like: "If I'm hacking PS3, then #ifndef CONFIG_PPC64 is guaranteed to be false, so I can just ignore the code guarded by them". But if we add a PPC_BOOK3S_64_BE, it will take a little more effort to see this. Regards, Boqun --GvXjxJ+pjyke8COw Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAABCAAGBQJV76a4AAoJEEl56MO1B/q45noIALHAdUeKxv0hNzd/3jRl0fi+ 8QK2ThUrBVyLiReocMjT3YqIQWLOj5dEi9Tu3Gv4xEmnz8aXZ/FyDsP67vTkgSDQ J4lvtrX+xlgu3/icUYaVsu4KiFdZbpiAjB5PBtdfp1qbWZQcQR1YKmhi7Sx+cxMD CCT8RY44/ny9JsHOnJbVHCtdP9AMqY+ol7dyM8r8VEXC5iSU8A2+48ka9TD20u0v gtgUBRQ8p1l2B0yZB5UvA14tF2gj8JlXvxR9aPL9wBemnNmH0IMHmKxu503q3bAJ +9ttBQSZdL5qLHyHPX+VtiJtAlHGXdNS99wv7tziK1NHDTOEOn2TBgy9t+ZCvDA= =BSSN -----END PGP SIGNATURE----- --GvXjxJ+pjyke8COw--