Re: [PATCH v2] net: macb: do not scan PHYs manually

Andrew Lunn
2016-04-28T21:23:21Z

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

&fec1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_enet1>;
phy-supply = <&reg_enet_3v3>;
phy-mode = "rgmii";
phy-handle = <&ethphy1>;
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 = <&ethphy2>;
status = "okay";
};

This even has the two phys on one bus, as you described...

Andrew