From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-in-01.arcor-online.net (mail-in-01.arcor-online.net [151.189.21.41]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.arcor.de", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 26F23DDF5C for ; Fri, 15 Jun 2007 18:37:11 +1000 (EST) In-Reply-To: <1181866571.14818.416.camel@localhost.localdomain> References: <20070612181825.730300780@am.sony.com> > <466EEC01.6080807@am.sony.com> <20070613084023.GA28629@aepfle.de><46702AFE.8080800@am.sony.com> <20070613181854.GA723@aepfle.de> <1181774801.14818.343.camel@localhost.localdomain> <590cd31b74053f7499c1f53a29639175@kernel.crashing.org> <9696D7A991D0824DBA8DFAC74A9C5FA302F33549@az33exm25.fsl.freescale.net> <480f44878c42c1dc6452233f9e21d663@kernel.crashing.org> <1181866571.14818.416.camel@localhost.localdomain> Mime-Version: 1.0 (Apple Message framework v623) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <437e7506d33016c4fa3cf89ad3ded0ae@kernel.crashing.org> From: Segher Boessenkool Subject: Re: [patch 29/30] PS3: Device tree source. Date: Fri, 15 Jun 2007 10:37:03 +0200 To: Benjamin Herrenschmidt Cc: linuxppc-dev@ozlabs.org, Olaf Hering , paulus@samba.org, Yoder Stuart-B08248 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , >> "node name" in flat device trees doesn't allow a proper >> "name" property to exist for the root node. This is a >> bug in the flat device tree tools, and either should be >> fixed, or this should be clearly documented as a divergence >> from "real" OF. >> >> "name" of the root node is a bit special, since it is >> never displayed as part of a device path or used for >> device selection (instead, "/" at start of a path is >> handled specially, just like on unix filesystems). > > This 'special' behaviour, the fact that it's definition is out of sync > with the generic name recommended practice, and finally, the fact that > quite a lot of real OFs out there don't even bother having one, makes > me > think that it's a good idea to stick to what I did, which is to say the > root node has no name in a flat device-tree. Putting that info in "compatible" instead should work fine enough. > Now, what I -may- do to avoid information loss is tweak prom_init.c to > actually extract that name if it exist and stick a "name" property in > the root node in that case when flattening the tree. Nice, thanks! > But I still beleive as far as flat DTs for embedded are concerned, we > shouldn't use and rely on having a name at the root of the tree. There _has_ to be a "name" property. But you have one, just not with interesting contents ;-) >> Since anything that matches for "compatible" entries >> also first should check the "name" contents, it should >> be okay for flat device trees to have the information >> that could/should be in "name" in "compatible", instead. Segher