From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Cartwright Subject: Re: [PATCH v2] net: macb: do not scan PHYs manually Date: Thu, 28 Apr 2016 19:34:59 -0500 Message-ID: <20160429003459.GC30217@jcartwri.amer.corp.natinst.com> References: <1461854802-8142-1-git-send-email-nathan.sullivan@ni.com> <57222FCE.8050407@atmel.com> <20160428155556.GA8333@nathan3500-linux-VM> <20160428163207.GP29024@lunn.ch> <20160428175619.GA8791@nathan3500-linux-VM> <20160428184303.GR29024@lunn.ch> <20160428185527.GA8851@nathan3500-linux-VM> <20160428185932.GU29024@lunn.ch> <20160428210357.GB30217@jcartwri.amer.corp.natinst.com> <20160428212315.GC12753@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Nathan Sullivan , Nicolas Ferre , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Florian Fainelli , Alexandre Belloni To: Andrew Lunn Return-path: In-Reply-To: <20160428212315.GC12753@lunn.ch> Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Thu, Apr 28, 2016 at 11:23:15PM +0200, Andrew Lunn wrote: > On Thu, Apr 28, 2016 at 04:03:57PM -0500, Josh Cartwright wrote: > > On Thu, Apr 28, 2016 at 08:59:32PM +0200, Andrew Lunn wrote: > > > On Thu, Apr 28, 2016 at 01:55:27PM -0500, Nathan Sullivan wrote: > > > > On Thu, Apr 28, 2016 at 08:43:03PM +0200, Andrew Lunn wrote: > > > > > > I agree that is a valid fix for AT91, however it won't solve our problem, since > > > > > > we have no children on the second ethernet MAC in our devices' device trees. I'm > > > > > > starting to feel like our second MAC shouldn't even really register the MDIO bus > > > > > > since it isn't being used - maybe adding a DT property to not have a bus is a > > > > > > better option? > > > > > > > > > > status = "disabled" > > > > > > > > > > would be the unusual way. > > > > > > > > > > Andrew > > > > > > > > Oh, sorry, I meant we use both MACs on Zynq, however the PHYs are on the MDIO > > > > bus of the first MAC. So, the second MAC is used for ethernet but not for MDIO, > > > > and so it does not have any PHYs under its DT node. It would be nice if there > > > > were a way to tell macb not to bother with MDIO for the second MAC, since that's > > > > handled by the first MAC. > > > > > > Yes, exactly, add support for status = "disabled" in the mdio node. > > > > Unfortunately, the 'macb' doesn't have a "mdio node", or alternatively: > > the node representing the mdio bus is the same node which represents the > > macb instance itself. Setting 'status = "disabled"' on this node will > > just prevent the probing of the macb instance. > > :-( > > It is very common to have an mdio node within the MAC node, for example imx6sx-sdb.dtsi Okay, I think that makes sense. I think, then, perhaps the solution to our problem is to: 1. Modify the macb driver to support an 'mdio' node. (And adjust the binding document accordingly). If the node is found, it's used for of_mdiobus_register() w/o any of the manual scan madness. 2. For backwards compatibility, in the case where an 'mdio' node does not exist, leave the existing behavior the way it is now (of_mdiobus_register() followed by manual scan) [perhaps warn of deprecation as well?] 3. Update binding docs to reflect the above. In this way, for our usecase, the 'status = "disabled"' in the newly created 'mdio' node isn't necessary. It's sufficient for the node to exist and be empty. > &fec1 { > pinctrl-names = "default"; > pinctrl-0 = <&pinctrl_enet1>; > phy-supply = <®_enet_3v3>; > phy-mode = "rgmii"; > phy-handle = <ðphy1>; > status = "okay"; > > mdio { > #address-cells = <1>; > #size-cells = <0>; > > ethphy1: ethernet-phy@1 { > reg = <1>; > }; > > ethphy2: ethernet-phy@2 { > reg = <2>; > }; > }; > }; > > &fec2 { > pinctrl-names = "default"; > pinctrl-0 = <&pinctrl_enet2>; > phy-mode = "rgmii"; > phy-handle = <ðphy2>; > status = "okay"; > }; > > This even has the two phys on one bus, as you described... Yep...looks nearly exactly the same case. Thanks, Josh