Re: [PATCH net-next v2 5/6] net: dsa: mv88e6xxx: MQPRIO support

[Luke Howard]

> On 3 Jun 2026, at 7:12 am, Luke Howard <lukeh@xxxxxxxx> wrote:
> 
>> In case of per port priority mapping, i don't know if this is working as
>> expected, as the IEEE priority mapping is done at ingress.
>> Eg. i think if MQPRIO channel mode is used to configure a pcp to queue mapping
>> on port 1 and a different mapping on port 2. Traffic received on port 1 that
>> gets forwarded to port 2 and egresses port 2 will end up in the queue
>> configured by the mapping on port 1. As mqprio is an egress qdisc, i don't
>> think that's expected.
> 
> Good point, it’s interesting there is egress mapping on the 6390 but only for FPri to DSCP. The Frame Priority Table set ordinal one would expect for egress QPri mapping is “reserved for future use”. (Be nice if it were an undocumented feature.)

I misread the data sheet. Egress PCP to FPRI mapping is possible per-port on the 6390 family. This doesn’t resolve the other issue (MQPRIO-less ports on the 6352 family). But it is good news and I will revise accordingly in the next patch revision.