Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932427AbdHVIAL (ORCPT ); Tue, 22 Aug 2017 04:00:11 -0400 Received: from mail-wr0-f194.google.com ([209.85.128.194]:36466 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932093AbdHVIAI (ORCPT ); Tue, 22 Aug 2017 04:00:08 -0400 Date: Tue, 22 Aug 2017 09:59:58 +0200 From: Corentin Labbe To: Andrew Lunn Cc: Maxime Ripard , Chen-Yu Tsai , Rob Herring , Mark Rutland , Russell King , Giuseppe Cavallaro , Alexandre Torgue , devicetree , linux-arm-kernel , linux-kernel , netdev Subject: Re: [PATCH v3 3/4] net: stmmac: register parent MDIO node for sun8i-h3-emac Message-ID: <20170822075958.GA20320@Red> References: <20170818122118.4925-4-clabbe.montjoie@gmail.com> <20170819185025.GB13266@Red> <20170819203836.GA21567@lunn.ch> <20170820065757.GA6081@Red> <20170820142545.GB24150@lunn.ch> <20170821132015.GB1703@lunn.ch> <20170821133104.qvrhvwin2rdg4aqo@flea.lan> <20170821142321.GE1703@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170821142321.GE1703@lunn.ch> User-Agent: Mutt/1.7.2 (2016-11-26) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1801 Lines: 51 On Mon, Aug 21, 2017 at 04:23:21PM +0200, Andrew Lunn wrote: > > All muxes are mostly always represented the same way afaik, or do you > > want to simply introduce a new compatible / property? > > + mdio-mux { > + compatible = "allwinner,sun8i-h3-mdio-switch"; > + mdio-parent-bus = <&mdio_parent>; > + #address-cells = <1>; > + #size-cells = <0>; > + > + internal_mdio: mdio@1 { > reg = <1>; > - clocks = <&ccu CLK_BUS_EPHY>; > - resets = <&ccu RST_BUS_EPHY>; > + #address-cells = <1>; > + #size-cells = <0>; > + int_mii_phy: ethernet-phy@1 { > + compatible = "ethernet-phy-ieee802.3-c22"; > + reg = <1>; > + clocks = <&ccu CLK_BUS_EPHY>; > + resets = <&ccu RST_BUS_EPHY>; > + phy-is-integrated; > + }; > + }; > + mdio: mdio@0 { > + reg = <0>; > + #address-cells = <1>; > + #size-cells = <0>; > }; > > Hi Maxim > > Anybody who knows the MDIO-mux code/binding, knows that it is a run > time mux. You swap the mux per MDIO transaction. You can access all > the PHY and switches on the mux'ed MDIO bus. > > However here, it is effectively a boot-time MUX. You cannot change it > on the fly. What happens when somebody has a phandle to a PHY on the > internal and a phandle to a phy on the external? Does the driver at > least return -EINVAL, or -EBUSY? Is there a representation which > eliminates this possibility? > Exactly you can change it on the fly, but you need to reset the MAC for enabling the new configuration. The stmmac driver does not handle mdio-mux. It is why I have a patch which automaticly select parent MDIO node of the PHY node. For representation we could keep the current. (With a big comment stating that it is a switch) We can also add a mdio-switch type node, or add a mdio-switch property to mdio-mux. Regards