From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: [PATCH net 2/2] DT: phy.txt: Clarify expected compatible values Date: Wed, 27 Jan 2016 08:31:21 -0800 Message-ID: <1D1D50D7-5C95-4FD6-9919-6898DE05B5DA@gmail.com> References: <1453853499-11248-1-git-send-email-andrew@lunn.ch> <1453853499-11248-3-git-send-email-andrew@lunn.ch> <56A81047.4010802@gmail.com> <20160127010638.GA4815@lunn.ch> <56A81C7B.8050201@gmail.com> <20160127015755.GB4815@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: David Miller , netdev , aaro.koskinen@nokia.com, olof@lixom.net To: Andrew Lunn Return-path: Received: from mail-oi0-f68.google.com ([209.85.218.68]:36776 "EHLO mail-oi0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932158AbcA0Qba (ORCPT ); Wed, 27 Jan 2016 11:31:30 -0500 Received: by mail-oi0-f68.google.com with SMTP id y78so595424oif.3 for ; Wed, 27 Jan 2016 08:31:30 -0800 (PST) In-Reply-To: <20160127015755.GB4815@lunn.ch> Sender: netdev-owner@vger.kernel.org List-ID: On January 26, 2016 5:57:55 PM PST, Andrew Lunn wrote: >> Well, we do now, since that is one of the results used by >> of_mdiobus_child_is_phy(), > >It uses it, but do not rely on it, since for backwards compatibility, >we cannot assume it is there. > >You can never change an optional parameter to a mandatory parameter in >DT. To do so breaks backwards compatibility. > >> What I would prefer seeing though is not removing nodes that have at >> least two compatible strings, including one that is >> "ethernet-phy-ieee802.3-c22", but those which have only one, like the >> marvell ones that you patch, should have either an additional >> "ethernet-phy-ieee802.3-c22", or none. > >So you are saying, if there is an "ethernet-phy-ieee802.3-c22" or an >"ethernet-phy-ieee802.3-45" you can also have any other random junk, >which we are going to ignore, since we have no way to verify, hence we >have to assume it is broken, yet we need to be backwards compatible >with it. > >Did you notice: > >+ { .compatible = "marvell,88e1310", }, >+ { .compatible = "marvell,88E1510", }, > >No consistency with the 'e'. We would just be encouraging people to >add more inconsistent stuff. You are right, I am convinced now. If somebody needs to know the exact PHY ID a priori, then you are also likely to use the more descriptive compatible string including that ID. So: Acked-by: Florian Fainelli -- Florian