From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Korsgaard Subject: Re: [RFC] [PATCH] Device Tree on ARM platform Date: Wed, 27 May 2009 17:41:47 +0200 Message-ID: <87vdnm8sec.fsf@macbook.be.48ers.dk> References: <1243408083.13460.14.camel@debian-nb> <20090527150527.GK6805@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090527150527.GK6805-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> (Robert Schwebel's message of "Wed\, 27 May 2009 17\:05\:27 +0200") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-mnsaURCQ41sdnm+yROfE0A@public.gmane.org Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-mnsaURCQ41sdnm+yROfE0A@public.gmane.org To: Robert Schwebel Cc: devicetree-discuss , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-xIg/pKzrS19vn6HldHNs0ANdhmdF6hFW@public.gmane.org, Janboe Ye , Timur Tabi , rmk-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org List-Id: devicetree@vger.kernel.org >>>>> "Robert" == Robert Schwebel writes: Hi, Robert> - The whole concept is based on the assumption that bindings Robert> are defined *once*, then never to be changed again. As this Robert> is not true (check MPC5200 to find out what I mean), oftree Robert> wreckage is *the* main cause of new kernels not working on Robert> old bootloaders any more. Is there a solution of this Robert> problem? I have not seen a good idea how to avoid the Robert> constant change in definitions. Just bundle the .dtb with the kernel and they'll always be in sync. I know this isn't really in the spirit of OF, but currently imho the only realistic solution. I did a (nacked) patch to do this with the multi-image support in U-Boot some time ago: http://patchwork.ozlabs.org/patch/589/ Robert> - The oftree layering is fundamentally broken. We already Robert> have a sane abstraction for arbitrary hardware in the kernel: Robert> platform devices. Why not instanciate platform devices from Robert> a generic oftree core? Robert> - Platform data makes it possible to store function Robert> pointers. There is no equivalent to this concept in Robert> oftree-land. Yeah. -- Bye, Peter Korsgaard