Re: RFC: Advice on adding support for Qualcomm IPQ9574 SoC Ethernet

[Andrew Lunn]

> Agree that switchdev is the right model for this device. We were
> planning to enable base Ethernet functionality using regular
> (non-switchdev) netdevice representation for the ports initially,
> without offload support. As the next step, L2/VLAN offload support using
> switchdev will be enabled on top. Hope this phased approach is fine.

Since it is not a DSA switch, yes, a phased approach should be O.K.

> >> 3) PCS driver patch series:
> >>         Driver for the PCS block in IPQ9574. New IPQ PCS driver will
> >>         be enabled in drivers/net/pcs/
> >> 	Dependent on NSS CC patch series (2).
> > 
> > I assume this dependency is pure at runtime? So the code will build
> > without the NSS CC patch series?
> 
> The MII Rx/Tx clocks are supplied from the NSS clock controller to the
> PCS's MII channels. To represent this in the DTS, the PCS node in the
> DTS is configured with the MII Rx/Tx clock that it consumes, using
> macros for clocks which are exported from the NSS CC driver in a header
> file. So, there will be a compile-time dependency for the dtbindings/DTS
> on the NSS CC patch series. We will clearly call out this dependency in
> the cover letter of the PCS driver. Hope that this approach is ok.

Since there is a compile time dependency, you might want to ask for
the clock patches to be put into a stable branch which can be merged
into netdev.

Or you need to wait a kernel cycle.

   Andrew