Re: [RFC PATCH 00/12] wifi: AP side locking improvements

[Johannes Berg <johannes@sipsolutions.net>]

On Sun, 2026-10-04 at 23:40 +0200, Johannes Berg wrote:
> This obviously goes on top of my (fixed) RTNL redux series.
> 
> The idea here is that wiphy mutex can be held for quite a bit
> of time (e.g. waiting for firmware), but beacon updates (e.g.
> with the critical update design I had proposed a long while
> back) and other things should be fast.
> 
> So with this not all things require wiphy mutex. These are:
> 
>  - beacon and related template updates
>    (this one needs driver opt-in),
>  - mgmt frame TX,
>  - control port TX, and
>  - peer probe.
> 
> This does make the implementation slightly more complex, but
> the added complexity is almost entirely in mac80211 (and some
> in cfg80211), unless a driver wants to opt in to unlocked
> beacon/template updates, which it has to implement itself for
> obvious reasons.

Thinking about this some more, there are a couple of corner cases I
don't like:

 - the semantics of "only for netdevs" and the get_device() in the
   implementation are strange

 - because of that, we can't do this for non-AP, and NAN would benefit

If we add a refcount_t to wdevs for this, and then use wdev_hold()
instead of dev_hold() (which uses the netdev dev_hold if it's there)
then it starts working for everything and the implementation gets nicer
too.

I'll rework it accordingly for the next round.

johannes