On Wed, Aug 23, 2017 at 09:31:53AM -0700, Florian Fainelli wrote: > On 08/23/2017 12:49 AM, Maxime Ripard wrote: > > Hi Florian, > > > > On Tue, Aug 22, 2017 at 11:35:01AM -0700, Florian Fainelli wrote: > >>>>> So I think what you are saying is either impossible or engineering-wise > >>>>> a very stupid design, like using an external MAC with a discrete PHY > >>>>> connected to the internal MAC's MDIO bus, while using the internal MAC > >>>>> with the internal PHY. > >>>>> > >>>>> Now can we please decide on something? We're a week and a half from > >>>>> the 4.13 release. If mdio-mux is wrong, then we could have two mdio > >>>>> nodes (internal-mdio & external-mdio). > >>>> > >>>> I really don't see a need for a mdio-mux in the first place, just have > >>>> one MDIO controller (current state) sub-node which describes the > >>>> built-in STMMAC MDIO controller and declare the internal PHY as a child > >>>> node (along with 'phy-is-integrated'). If a different configuration is > >>>> used, then just put the external PHY as a child node there. > >>>> > >>>> If fixed-link is required, the mdio node becomes unused anyway. > >>>> > >>>> Works for everyone? > >>> > >>> If we put an external PHY with reg=1 as a child of internal MDIO, > >>> il will be merged with internal PHY node and get > >>> phy-is-integrated. > >> > >> Then have the .dtsi file contain just the mdio node, but no internal or > >> external PHY and push all the internal and external PHY node definition > >> (in its entirety) to the per-board DTS file, does not that work? > > > > If possible, I'd really like to have the internal PHY in the > > DTSI. It's always there in hardware anyway, and duplicating the PHY, > > with its clock, reset line, and whatever info we might need in the > > future in each and every board DTS that uses it will be very error > > prone and we will have the usual bunch of issues that come up with > > duplication. > > OK, then what if you put the internal PHY in the DTSI, mark it with a > status = "disabled" property, and have the per-board DTS put a status = > "okay" property along with a "phy-is-integrated" boolean property? Would > that work? Yeah, that would work for me. > What I really don't think is necessary is: > > - duplicating the "mdio" controller node for external vs. internal PHY, > because this is not accurate, there is just one MDIO controller, but > there may be different kinds of MDIO/PHY devices attached Agreed. > - having the STMMAC driver MDIO probing code having to deal with a > "mdio" sub-node or an "internal-mdio" sub-node because this is confusing > and requiring more driver-level changes that are error prone I don't really have an opinion on that one, so I'll defer to your judgment of what's best :) I guess we have an agreement. Andrew, is that ok for you too? Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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