Re: [PATCH net-next v8 2/3] net: dsa: mv88e6xxx: use the hw tx queues

[Jakub Kicinski]

On Tue, 11 Aug 2026 13:45:48 +0200 Cedric Jehasse via B4 Relay wrote:
> When transmitting fill in the PRI field in the dsa tag to select the
> egress queue is sent to.
> From the datasheets i've looked at these switches have 4 or 8 transmit
> queues per port.
> Note: skbs with skb->offload_fwd_mark set use the DSA_CMD_FORWARD
> tag. These are processed as normal ingress frames, meaning the queue
> they end up in can still be altered by other switch config. eg. priority
> overrides, tcam policies.
> This isn't done for vlan tagged frames because this would overwrite the
> PCP value in the vlan tag (The PRI field in the dsa
> tag is used as the PCP value in the vlan tag).

Pretending that a DSA device has multiple Tx queues _from the stack_
makes no sense. You should be offloading PRIO as the root qdisc,
like mlxsw does. Then the rate limiters should be attached as children
of PRIO.