Re: [RFC PATCH v3 08/12] iwlwifi: dvm - EXT_KEY_ID A-MPDU API update

[Johannes Berg <johannes@sipsolutions.net>]

On Fri, 2019-02-22 at 22:15 +0100, Alexander Wetzel wrote:

> I hoped that the HW would already enforce the key border. 

I don't think so.

> But ok: The 
> cards will still be able to use NATIVE mode. Only now the driver will 
> have to request to disable Tx aggregation when finding a key border. 

It doesn't really have to even completely disable it, it'd just have to
send and LQ_CMD with agg_params.agg_frame_cnt_limit = 1, temporarily,
until the relevant frames were transmitted (this is a global config, so
it'd have to track the key border on each TID, but that's not _too_
hard).

> Since Tx aggregation is disabled per default anyhow many users will not 
> even see a difference.

Good point, I forgot all about that.

> (Off topic here, but I suspect the not reproducible problems leading to 
> change the Tx aggregation default to off could also have been ptk0 rekey 
> freezes. In that case we could now allow it again. But I've not found 
> raw error reports and guess it's not worth the efforts/risks to change 
> the default again.)

I wouldn't be so sure - PTK rekeying should still be a pretty uncommon
configuration. But I also don't recall the exact decision making going
into this.

johannes