Re: [PATCH net-next 2/2] net: dsa: mv88e6xxx: add support for credit based shaper

[Cedric Jehasse]

> From: Luke Howard <lukeh@xxxxxxxx>
> Sent: Tuesday, May 26, 2026 2:32 AM
> To: Cedric Jehasse
> Cc: Andrew Lunn; Vladimir Oltean; David S. Miller; Eric Dumazet; Jakub Kicinski; Paolo Abeni; Simon Horman; Russell King; netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Kieran Tyrrell; Max Hunter
> Subject: Re: [PATCH net-next 2/2] net: dsa: mv88e6xxx: add support for credit based shaper
> 
> Hi Cedric,
> 
> We sent RFC patches for mv88e6xxx support for both MQPRIO [1] and CBS [2] last year. (We have since made a few small changes which can be found in our working tree at [3].)
> 
> We have been using these patches successfully for the past year with our SRP stack [4] on a custom board with a 88E6352. The CBS and MQPRIO patches remain unsubmitted because we also needed extend the Netlink API and software bridge with a flag indicating a FDB/MDB entry is managed by SRP.
> 
> I would be happy to work together to harmonise our patches to avoid duplicated effort.
> 
> Cheers,
> Luke
> 
> [1] https://lists.openwall.net/netdev/2025/09/27/34
> [2] https://lists.openwall.net/netdev/2025/09/27/26
> [3] https://github.com/PADL/linux/tree/rpi-6.18.y-xebros-rmu
> [4] https://github.com/PADL/OpenSRP

I've looked at these patches before starting. I quickly ran into the limitation the driver only supports 3 traffic classes. I want to be able to send traffic from the cpu to other queues too.
I don't use MQPRIO hw offload, which i think is a big part of your changes. So it didn't make sense to continue on those patches. This also answers your other question: i haven't submitted another patch set for hardware offloaded MQPRIO. 
I'm trying to upstream changes one topic at a time. Eg. this CBS patch is only for configuring the shaper. How traffic ends up in a certain queue is not relevant for this patch.

Cedric