From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from de01egw02.freescale.net (de01egw02.freescale.net [192.88.165.103]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "de01egw02.freescale.net", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTP id B07F2DDEEF for ; Wed, 18 Jul 2007 08:25:18 +1000 (EST) Date: Tue, 17 Jul 2007 17:25:07 -0500 From: Scott Wood To: Benjamin Herrenschmidt Subject: Re: [RFC][PATCH 6/8] Walnut DTS Message-ID: <20070717222507.GA4682@ld0162-tx32.am.freescale.net> References: <1184161957.32199.52.camel@weaponx.rchland.ibm.com> <1184162389.32199.65.camel@weaponx.rchland.ibm.com> <4EAC985A-2F04-465D-AB69-C67807310D7B@kernel.crashing.org> <9696D7A991D0824DBA8DFAC74A9C5FA3030669AF@az33exm25.fsl.freescale.net> <28A3F6B9-512B-4D86-8E0D-A7680CCE2354@kernel.crashing.org> <1184622446.25235.89.camel@localhost.localdomain> <1184707558.25235.159.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1184707558.25235.159.camel@localhost.localdomain> Cc: linuxppc-dev@ozlabs.org, Yoder Stuart-B08248 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Jul 18, 2007 at 07:25:57AM +1000, Benjamin Herrenschmidt wrote: > > > which is why I tend to prefer having it > > > explicitely in the interrupt controller node :-) > > > > Which is simply incorrect. > > It's absolutely not. Please, stop that moronic pin-head behaviour and > find me a single case where that would actually be a problem of any sort > or form. It could lead someone to the erroneous conclusion that an #address-cells other than zero in an interrupt controller that is not a device parent is in any way a sane or supported thing to do. It could lead people to write code that doesn't handle the absence of #address-cells in such a node properly. It could lead to flamewars. :-) > > You mean, the magic default values you used for #address-cells > > and #size-cells? That was simply a bug, someone forgot to read > > the documentation... > > No, defaults are crap, period. If there's only one value that could possibly make sense, it *not* being the default is crap. > See above. Besides, as I said, default values are crap. And no, it's not > obvious which nodes define a physical address space or not, at least not > for a generic parser. The obvious way (which indeed isn't what the suggested algorithm does -- but the suggested algorithm doesn't do anything sensible) is that if you got to the node via an interrupt-parent or interrupt-map, it doesn't use #address-cells, and if you got to it by going to the regular device tree parent, it does. Pretty much any time you use the unit address in a context other than the bus parent, things cease making sense. > > In some areas, perhaps. And it would be nice to bring those > > areas to the attention of the working group, instead of just > > to complain. > > The working group is dead and some of the ex members of it expressed > their lack of interest in pursuing these matters. There is the ePAPR working group, though. -Scott