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 ESMTPS id 1B026DDF4B for ; Sat, 19 Apr 2008 19:24:04 +1000 (EST) In-Reply-To: <20080418161218.12738.25844.stgit@trillian.secretlab.ca> References: <20080418161218.12738.25844.stgit@trillian.secretlab.ca> Mime-Version: 1.0 (Apple Message framework v623) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <50bbe43673e46cc8d3a02eb4c03d87e9@kernel.crashing.org> From: Segher Boessenkool Subject: Re: [RFC/POWERPC] mpc5200: remove "mpc5200b-*" from compatible lists in dts files Date: Sat, 19 Apr 2008 11:23:57 +0200 To: Grant Likely Cc: linuxppc-dev@ozlabs.org, m8@semihalf.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > The mpc5200b is a bug fix of the mpc5200 with a few incompatible > changes. > By rights, the current dts trees are the most "correct", but in > practical > purposes there is no value in the 5200b devices having 2 compatible > entries for each internal peripheral node. Freescale has done a good > job > of documenting exactly where the incompatibilities lie, so it restrict > the extra compatible properties to devices with *documented* changes. And what happens when later an "undocumented change" is found? The device tree should always list the exact version of device used, even if all clients (i.e., the Linux kernel) only use the less-specific "compatible" value; that way, if a need to distinguish arises later (e.g., a model-specific bug workaround), a client can detect the exact model of device without needing a new device tree (that the client in general has no control over). > Removing the extra 'b' fields makes the device trees smaller That's nice in general, but it hardly overrides more serious concerns. Segher