Re: [PATCH net-next 5/6] arm64: dts: marvell: mcbin: enable the fourth network interface

Antoine Tenart
2017-12-28T10:05:40Z

Hi Andrew,

On Thu, Dec 28, 2017 at 08:46:23AM +0100, Andrew Lunn wrote:
> On Wed, Dec 27, 2017 at 10:24:01PM +0000, Russell King - ARM Linux wrote:
> > On Wed, Dec 27, 2017 at 11:14:45PM +0100, Antoine Tenart wrote:
> > >
> > > +&cps_eth2 {
> > > + /* CPS Lane 5 */
> > > + status = "okay";
> > > + phy-mode = "2500base-x";
> > > + /* Generic PHY, providing serdes lanes */
> > > + phys = <&cps_comphy5 2>;
> > > +};
> > > +
> >
> > This is wrong. This lane is connected to a SFP cage which can support
> > more than just 2500base-X. Tying it in this way to 2500base-X means
> > that this port does not support conenctions at 1000base-X, despite
> > that's one of the most popular and more standardised speeds.
> >
>
> I agree with Russell here. SFP modules are hot pluggable, and support
> a range of interface modes. You need to query what the SFP module is
> in order to know how to configure the SERDES interface. The phylink
> infrastructure does that for you.

Sure, I understand. We'll be able to support such interfaces only when
the phylink PPv2 support lands in.

Thanks!
Antoine

--
Antoine Ténart, Free Electrons
Embedded Linux and Kernel engineering