From mboxrd@z Thu Jan 1 00:00:00 1970 From: florian@openwrt.org (Florian Fainelli) Date: Tue, 22 Jan 2013 16:19:46 +0100 Subject: [PATCH] net: fec: Add support for multiple phys on mdiobus In-Reply-To: <50FEAA28.1070003@grandegger.com> References: <1358757475-21035-1-git-send-email-s.hauer@pengutronix.de> <50FD02B8.8080401@grandegger.com> <20130121100701.GX1906@pengutronix.de> <50FD2172.2020608@grandegger.com> <20130121120602.GZ1906@pengutronix.de> <50FE3E37.4010004@grandegger.com> <50FEA691.4050904@openwrt.org> <50FEAA28.1070003@grandegger.com> Message-ID: <50FEAE12.7090307@openwrt.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 01/22/2013 04:03 PM, Wolfgang Grandegger wrote: > On 01/22/2013 03:47 PM, Florian Fainelli wrote: >> On 01/22/2013 08:22 AM, Wolfgang Grandegger wrote: >>>> Well this could be done when the fixed phy driver could be registered >>>> with the devicetree, maybe like this: >>>> >>>> fixed-phy: mdiophy { >>>> compatible = "mdio-fixed-phy"; >>>> link = "100FD"; >>>> }; >>> I find that confusing. There is *no* phy but just a fixed link to the >>> switch... >>> >>>> The good thing about this would be that every ethernet driver could just >>>> use such a fixed phy, any external mdio phy (like on Marvell Armada) or >>>> just a phy connected to the internal mdio interface provided by the >>>> ethernet >>>> core. >>> What is wrong with the existing "fixed-link" property of the *ethernet* >>> node. The fixed-link handling should/could be done in the phy layer, and >>> not in the driver as it currently is implemented. Maybe that's the >>> reason why the current code is regarded as hack! >> As far as I have used it with the CPMAC driver, the fixed PHY is a >> specific PHY device and there is no specific handling to be done by the >> Ethernet MAC driver but eventually changing its MII bus id so that it is >> named "fixed-0" to allow the fixed PHY driver to bind. Put differently, > There is special handling for the fixed link, e.g. here: > > http://lxr.linux.no/#linux+v3.7.4/drivers/net/ethernet/freescale/gianfar.c#L1462 > > This could be hidden in the PHY layer allowing all ethernet drivers > using the "fixed-link" property. Ok, so in the end you could have potentially an ethernet PHY node containing the following properties: - fixed-link - fixed-speed - fixed-duplex and treat it as a fixed-phy. If so, this would be pretty handy. > >> using the fixed PHY driver is a kind of "last" resort thing to cope with >> situations like: >> >> - switch not providing a consistent PHY-like interface on the MDC/MDIO bus >> - switches not connected to the MDC/MDIO bus of the Ethernet MAC they >> forward to >> >> What exactly do you mean by "as it currently is implemented"? that you >> do not like? > As Sascha pointed out, the implementation is labeled as "hack", which > should be fixed sooner than later. It's just not clear why ;). > > Wolfgang. > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: [PATCH] net: fec: Add support for multiple phys on mdiobus Date: Tue, 22 Jan 2013 16:19:46 +0100 Message-ID: <50FEAE12.7090307@openwrt.org> References: <1358757475-21035-1-git-send-email-s.hauer@pengutronix.de> <50FD02B8.8080401@grandegger.com> <20130121100701.GX1906@pengutronix.de> <50FD2172.2020608@grandegger.com> <20130121120602.GZ1906@pengutronix.de> <50FE3E37.4010004@grandegger.com> <50FEA691.4050904@openwrt.org> <50FEAA28.1070003@grandegger.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Sascha Hauer , netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, shawn.guo@linaro.org, davem@davemloft.net To: Wolfgang Grandegger Return-path: Received: from mail-lb0-f170.google.com ([209.85.217.170]:46118 "EHLO mail-lb0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754343Ab3AVPWb (ORCPT ); Tue, 22 Jan 2013 10:22:31 -0500 Received: by mail-lb0-f170.google.com with SMTP id ge1so1723349lbb.1 for ; Tue, 22 Jan 2013 07:22:29 -0800 (PST) In-Reply-To: <50FEAA28.1070003@grandegger.com> Sender: netdev-owner@vger.kernel.org List-ID: On 01/22/2013 04:03 PM, Wolfgang Grandegger wrote: > On 01/22/2013 03:47 PM, Florian Fainelli wrote: >> On 01/22/2013 08:22 AM, Wolfgang Grandegger wrote: >>>> Well this could be done when the fixed phy driver could be registered >>>> with the devicetree, maybe like this: >>>> >>>> fixed-phy: mdiophy { >>>> compatible = "mdio-fixed-phy"; >>>> link = "100FD"; >>>> }; >>> I find that confusing. There is *no* phy but just a fixed link to the >>> switch... >>> >>>> The good thing about this would be that every ethernet driver could just >>>> use such a fixed phy, any external mdio phy (like on Marvell Armada) or >>>> just a phy connected to the internal mdio interface provided by the >>>> ethernet >>>> core. >>> What is wrong with the existing "fixed-link" property of the *ethernet* >>> node. The fixed-link handling should/could be done in the phy layer, and >>> not in the driver as it currently is implemented. Maybe that's the >>> reason why the current code is regarded as hack! >> As far as I have used it with the CPMAC driver, the fixed PHY is a >> specific PHY device and there is no specific handling to be done by the >> Ethernet MAC driver but eventually changing its MII bus id so that it is >> named "fixed-0" to allow the fixed PHY driver to bind. Put differently, > There is special handling for the fixed link, e.g. here: > > http://lxr.linux.no/#linux+v3.7.4/drivers/net/ethernet/freescale/gianfar.c#L1462 > > This could be hidden in the PHY layer allowing all ethernet drivers > using the "fixed-link" property. Ok, so in the end you could have potentially an ethernet PHY node containing the following properties: - fixed-link - fixed-speed - fixed-duplex and treat it as a fixed-phy. If so, this would be pretty handy. > >> using the fixed PHY driver is a kind of "last" resort thing to cope with >> situations like: >> >> - switch not providing a consistent PHY-like interface on the MDC/MDIO bus >> - switches not connected to the MDC/MDIO bus of the Ethernet MAC they >> forward to >> >> What exactly do you mean by "as it currently is implemented"? that you >> do not like? > As Sascha pointed out, the implementation is labeled as "hack", which > should be fixed sooner than later. It's just not clear why ;). > > Wolfgang. > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html