Why don't we just build the rate control algorithms entirely separate
useing obj-$(FOO) ?  If they're modular that lets them be their own
module, and if they're built-in they'll still go into built-in.o.

Yeah. Except that they can't be built-in if mac80211 isn't, and we've
repeatedly had users f' up their installations and bitterly report to us
that mac80211 doesn't work because no rate control algorithm is
available so we wanted to force having one built into mac80211.ko unless
specifically turned off (only with EMBEDDED).

johannes