Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756557Ab3G3B51 (ORCPT ); Mon, 29 Jul 2013 21:57:27 -0400 Received: from ozlabs.org ([203.10.76.45]:35231 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751693Ab3G3B50 (ORCPT ); Mon, 29 Jul 2013 21:57:26 -0400 Date: Tue, 30 Jul 2013 11:50:31 +1000 From: David Gibson To: Jason Cooper Cc: Dave Martin , Mark Rutland , Tomasz Figa , Wolfram Sang , Grant Likely , Russell King - ARM Linux , Jason Gunthorpe , "devicetree@vger.kernel.org" , Ian Campbell , Pawel Moll , Stephen Warren , Richard Cochran , Domenico Andreoli , "linux-arm-kernel@lists.infradead.org" , James Bottomley , "ksummit-2013-discuss@lists.linuxfoundation.org" , "linux-kernel@vger.kernel.org" , "jonsmirl@gmail.com" Subject: Re: [Ksummit-2013-discuss] Defining schemas for Device Tree Message-ID: <20130730015031.GK29970@voom.fritz.box> References: <2469263.vMN09Q7Tzi@flatron> <20130729150124.GS29916@titan.lakedaemon.net> <20130729164905.GB2280@localhost.localdomain> <20130729172339.GT29916@titan.lakedaemon.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="q6mBvMCt6oafMx9a" Content-Disposition: inline In-Reply-To: <20130729172339.GT29916@titan.lakedaemon.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2471 Lines: 66 --q6mBvMCt6oafMx9a Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jul 29, 2013 at 01:23:39PM -0400, Jason Cooper wrote: > On Mon, Jul 29, 2013 at 05:49:05PM +0100, Dave Martin wrote: > > On Mon, Jul 29, 2013 at 11:01:24AM -0400, Jason Cooper wrote: > > > On Mon, Jul 29, 2013 at 02:21:52AM +0200, Tomasz Figa wrote: >=20 > > > > b) What information should be specified in schemas? What level of= =20 > > > > granularity is required? > > >=20 > > > One item I don't see in this list is node ordering. There's been some > > > discussion lately on deferred probing (re boot times). If we were to > > > intentionally declare that DT are parsed in the order written, then a > > > lot of deferred probes could be avoided by moving eg the pinctrl node= to > > > near the top of the tree. > > >=20 > > > This doesn't impact buses as much, since the nodes needing the bus are > > > already children. However, anything accessed via phandles: pins, > > > clocks, regulators, etc could benefit from declaring and enforcing th= is. > > > Eg having the dtc warn when a phandle is used before it's correspondi= ng > > > node is declared. > > >=20 > > > Not critical though, just a thought. > >=20 > > I don't think that siblings have any defined order in DT. If reading a > > device tree, there's no guarantee you get nodes or properties out in the > > same order as the original .dts file. >=20 > That's why I raised the point. If people think encoding initialization > order in the DT is a good idea, then we should change the dtc so it > compiles/decompiles in the same order. I'm not actually sure what you mean by this. dtc already preserves order between input and output. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --q6mBvMCt6oafMx9a Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) iEYEARECAAYFAlH3G+cACgkQaILKxv3ab8YmcgCdEzwCl0StxQVzfzE3aDk/O3VC 4ecAniijNIkuDXdYsEFyuKWIot7e43hX =4bCl -----END PGP SIGNATURE----- --q6mBvMCt6oafMx9a-- -- 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/