[dpdk-dev] [PATCH] doc: update new ethdev offload API description

[Thomas Monjalon]

21/03/2018 15:28, Ferruh Yigit:
> On 3/21/2018 2:08 PM, Thomas Monjalon wrote:
> > 21/03/2018 11:54, Ferruh Yigit:
> >> On 3/21/2018 9:47 AM, Andrew Rybchenko wrote:
> >>> IMHO, it should be allowed to specify queue offloads on port level.
> >>> It should simply enable these offloads on all queues. Also it will
> >>> match dev_info [rt]x_offload_capa which include both port and queue
> >>> offloads.
> >>>
> >>> Yes, we lose possibility to enable on port level, but disable on queue
> >>> level by suggested changes, but I think it is OK - if you don't need
> >>> it for all queues, just control separately on queue level.
> >>
> >> What I understand was queue offload can only enable more, but it seems it can
> >> both enable or disable.
> > 
> > Yes, queue offload should only enable more.
> > An offload enabled at port level, cannot be disabled at queue level.
> 
> Agree an offload enabled at port level can't be disabled at queue level, but why
> not have the ability to disable a queue level offload with another queue setup call.

Yes it should be possible to disable a queue offload:
1/ enable offload in queue configuration
2/ later disable this offload in queue configuration

So, when I say "only enable more", I mean queue config should only enable
more than port config. In other words, a port-level offload cannot be
disabled at queue level.

> > A port offload can be repeated in queue configuration.
> > If a port offload is not repeated in queue configuration, there should be
> > no impact: it is still in the port configuration, thus applying to all queues.
> 
> This was a requirement, this patch targets removing the requirement to repeat
> the port offload in queue config.

Understood, and I agree with this change if it is well explained
in sphinx and doxygen.
It is important to say that queue configuration has no impact on offloads
already enabled at port level.

> > About capabilities, the queue offloads must be a subset of port offloads.
> > The queue capabilities show which offloads can be enabled per queue.