Re: [PATCH net-next v3 2/8] taprio: Add support for frame preemption offload

Vinicius Costa Gomes
2021-01-29T23:14:20Z

Jakub Kicinski <kuba@kernel.org> writes:
>> > First I'm interested in the means: why check for preempt == U32_MAX when
>> > you determine that all traffic classes are preemptible? What if less
>> > than 32 traffic classes are used by the netdev? The check will be
>> > bypassed, won't it?
>>
>> Good catch :-)
>>
>> I wanted to have this (at least one express queue) handled in a
>> centralized way, but perhaps this should be handled best per driver.
>
> Centralized is good. Much easier than reviewing N drivers to make sure
> they all behave the same, and right.

The issue is that it seems that not all drivers/hw have the same
limitation: that at least one queue needs to be configured as
express/not preemptible.

That's the point I was trying to make when I suggested for the check to
be done per-driver, different limitations.

Cheers,
--
Vinicius