From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 4047F67BAC for ; Wed, 13 Dec 2006 09:46:41 +1100 (EST) Subject: Re: [PATCH] powerpc: consolidate mpc83xx platform files From: Benjamin Herrenschmidt To: Scott Wood In-Reply-To: <457F300F.7000203@freescale.com> References: <20061208190758.6cee088f.kim.phillips@freescale.com> <1165648490.1103.117.camel@localhost.localdomain> <91EF8E0D-06BC-47FD-89E6-6350430946F9@kernel.crashing.org> <20061211155155.26868ca6.kim.phillips@freescale.com> <20061211201055.21031c9b.kim.phillips@freescale.com> <1165890570.11914.5.camel@localhost.localdomain> <457F1F6E.4020502@freescale.com> <457F300F.7000203@freescale.com> Content-Type: text/plain Date: Wed, 13 Dec 2006 09:46:35 +1100 Message-Id: <1165963595.11914.101.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 2006-12-12 at 16:41 -0600, Scott Wood wrote: > Kumar Gala wrote: > > On Dec 12, 2006, at 3:30 PM, Scott Wood wrote: > >> They *may* not want to (and they certainly shouldn't be forced to), but > >> some may not want to define a new ppc_md (or modify a probe function) > >> for every new board if all of the differences are encapsulated in the > >> device tree. I thought one of the main goals of having a device tree is > >> that if it's done right, the kernel need not know about every single > >> model of board, just the different components that a device tree can > >> specify. > > > > That's true, and if that's the case you'd just set your "model" to > > match an existing supported ppc_md. > > Having an 831x explicitly claim to be an 834x is just a tad icky... Indeed, but "compatible" doesn't mean exact match and can be a list. In fact, it should probably be the other way around, that is 834x claim to be compatible with 831x... something like: "834x\0831x\083xx" (with appropriate board name appended of course). > And an 83xx-generic machine description does not stop them from doing > so. "Generic" does not mean "universal". It means "there's nothing > special about this board". If you need board-specific code in the > kernel, then don't label it generic. As long as you are careful enough so that your "generic" ppc_md. doesn't try to match everything with a 83xx in it :-0 Ben.