From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752575AbcD1WMU (ORCPT ); Thu, 28 Apr 2016 18:12:20 -0400 Received: from vps0.lunn.ch ([178.209.37.122]:52534 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751513AbcD1WMR (ORCPT ); Thu, 28 Apr 2016 18:12:17 -0400 Date: Fri, 29 Apr 2016 00:12:11 +0200 From: Andrew Lunn To: Florian Fainelli Cc: netdev@vger.kernel.org, davem@davemloft.net, nathan.sullivan@ni.com, nicolas.ferre@atmel.com, Rob Herring , Frank Rowand , Grant Likely , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE" , open list Subject: Re: [PATCH net-next] of: of_mdio: Check if MDIO bus controller is available Message-ID: <20160428221211.GE12753@lunn.ch> References: <1461880510-27132-1-git-send-email-f.fainelli@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1461880510-27132-1-git-send-email-f.fainelli@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 28, 2016 at 02:55:10PM -0700, Florian Fainelli wrote: > Add a check whether the 'struct device_node' pointer passed to > of_mdiobus_register() is an available (aka enabled) node in the Device > Tree. > > Rationale for doing this are cases where an Ethernet MAC provides a MDIO > bus controller and node, and an additional Ethernet MAC might be > connecting its PHY/switches to that first MDIO bus controller, while > still embedding one internally which is therefore marked as "disabled". > > Instead of sprinkling checks like these in callers of > of_mdiobus_register(), do this in a central location. I think this discussion has shown there is no documented best practices for MDIO bus drivers and how PHYs nodes are placed within device tree. Maybe you could document the generic MDIO binding, both as integrated into a MAC device node, and as a separate device? Andrew