From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751913Ab3G0Thl (ORCPT ); Sat, 27 Jul 2013 15:37:41 -0400 Received: from mail-ob0-f177.google.com ([209.85.214.177]:60351 "EHLO mail-ob0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751402Ab3G0Thj (ORCPT ); Sat, 27 Jul 2013 15:37:39 -0400 MIME-Version: 1.0 In-Reply-To: <20130726142140.GR24642@n2100.arm.linux.org.uk> References: <51F168FC.9070906@wwwdotorg.org> <20130725182920.GA24955@e106331-lin.cambridge.arm.com> <20130725184834.GA8296@netboy> <20130725213753.GC17616@obsidianresearch.com> <20130726080115.GA5436@netboy> <1374831744.2923.42.camel@shinybook.infradead.org> <20130726130927.GC4219@netboy> <20130726132709.GH29916@titan.lakedaemon.net> <1374846070.14574.92.camel@i7.infradead.org> <20130726142140.GR24642@n2100.arm.linux.org.uk> From: Grant Likely Date: Sat, 27 Jul 2013 13:37:19 -0600 X-Google-Sender-Auth: 7x4915sHawyelWT4kqfVK1i0jys Message-ID: Subject: Re: [Ksummit-2013-discuss] DT bindings as ABI [was: Do we have people interested in device tree janitoring / cleanup?] To: Russell King - ARM Linux Cc: "jonsmirl@gmail.com" , David Woodhouse , Jason Cooper , Mark Rutland , "devicetree@vger.kernel.org" , "ksummit-2013-discuss@lists.linuxfoundation.org" , Ian Campbell , Pawel Moll , Stephen Warren , Richard Cochran , Domenico Andreoli , "rob.herring@calxeda.com" , "linux-kernel@vger.kernel.org" , Jason Gunthorpe , Dave P Martin , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 26, 2013 at 8:21 AM, Russell King - ARM Linux wrote: > On Fri, Jul 26, 2013 at 10:14:32AM -0400, jonsmirl@gmail.com wrote: >> Yes, yes - that's why the schema should be written down and used as a >> validation input to dtc. Then dtc can spit out errors for non-standard >> items. There would be two versions - the standard one and a legacy one >> that includes the standard one plus the hacks that can't be undone. >> >> But more importantly it provides a framework for people creating new >> node definitions. Now they can't work in a vacuum and come up with >> random names and structure for everything. >> >> Most of the problems express in the thread would go away if the schema >> was written down and discussed. The rule going forward would be no new >> nodes that aren't part of the standard schema. > > So this is why I'm seeing patches just a short time ago removing existing > compatible strings from the DT descriptions and associated driver, and > replacing them with new ones... meaning that the old DT files won't work > with newer kernels. > > What that means is using the descriptions as the schema won't catch that > because they're changing those as well to match. > > There's a solution to that: dtc becomes a separate project external to > the kernel which also contains the schemas that it verifies against. > That way, if you want to make changes such as that above, you need to > get it past not only kernel people but also past dtc maintainers - > which increases the chances of such stuff being caught. +1 dtc has always been a separate project that happens to be mirrored in the kernel tree, but the bindings need to come out be turned into schema that can be validated. g.