net/sched: mqprio: add an extack message to mqprio_parse_opt()

Ferenc reports that a combination of poor iproute2 defaults and obscure
cases where the kernel returns -EINVAL make it difficult to understand
what is wrong with this command:

$ ip link add veth0 numtxqueues 8 numrxqueues 8 type veth peer name veth1
$ tc qdisc add dev veth0 root mqprio num_tc 8 map 0 1 2 3 4 5 6 7 \
        queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7
RTNETLINK answers: Invalid argument

Hopefully with this patch, the cause is clearer:

Error: Device does not support hardware offload.

The kernel was (and still is) rejecting this because iproute2 defaults
to "hw 1" if this command line option is not specified.

Link: https://lore.kernel.org/netdev/[email protected]/
Signed-off-by: Vladimir Oltean <[email protected]>
Reviewed-by: Ferenc Fejes <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Acked-by: Jamal Hadi Salim <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

0 files changed, 0 insertions, 0 deletions