On Fri, Jun 21, 2024 at 09:25:55AM +0200, Kurt Kanzenbach wrote:
> Add support for offloading MQPRIO. The hardware has four priorities as well
> as four queues. Each queue must be a assigned with a unique priority.
>
> However, the priorities are only considered in TSN Tx mode. There are two
> TSN Tx modes. In case of MQPRIO the Qbv capability is not required.
> Therefore, use the legacy TSN Tx mode, which performs strict priority
> arbitration.
>
> Example for mqprio with hardware offload:
>
> |tc qdisc replace dev ${INTERFACE} handle 100 parent root mqprio num_tc 4 \
> | map 0 0 0 0 0 1 2 3 0 0 0 0 0 0 0 0 \
> | queues 1@0 1@1 1@2 1@3 \
> | hw 1
>
> The mqprio Qdisc also allows to configure the `preemptible_tcs'. However,
> frame preemption is not supported yet.
>
> Tested on Intel i225 and implemented by following data sheet section 7.5.2,
> Transmit Scheduling.
>
> Signed-off-by: Kurt Kanzenbach <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
