[00/40] wifi: cfg80211/mac80211: locking cleanups

Message

Johannes Berg Aug. 28, 2023, 11:59 a.m. UTC

Hi,

So ... I mentioned a few months ago this was the direction I was
going in, and now here I have it. We've been running with it for
a while, and it looks good.

There's a kind of pointless commit in there that adds some wiphy
locking assertions to the wdev as an intermediate step, I can
remove that if you think that's better. We ran with it at that
intermediate stage for a while to test things.

As you can see in the list of patches, mutexes are removed:

 * in mac80211: sta_mtx, key_mtx, chanctx_mtx, ampdu_mlme.mtx,
                local->mtx, and iflist_mtx is reduced to just
                a driver helper mutex basically
 * in cfg80211, and was used by mac80211, the wdev mutex

This also fixes a number of potential deadlocks lockdep would
report in multi-link scenarios, but generally of course radically
simplifies locking, no more worries about dependencies between
the different mutexes in mac80211, etc.

johannes