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

[Kiran Kumar C . S . K]

On 10/4/2024 12:12 AM, Andrew Lunn wrote:
>> 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.
> 

Ok.

>>>> 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.
> 

Sure. We will request for such a stable branch merge once the NSS CC
patches are accepted by the reviewers. Could the 'net' tree be one such
stable branch option to merge the NSS CC driver?


> Or you need to wait a kernel cycle.>
Understand.

>    Andrew