There's a fun problem with (at least) the AR9331 in (at least) monitor mode:
* ar9300_load_nf: *** TIMEOUT while waiting for nf to load: AR_PHY_AGC_CONTROL=0x1d0dda ***
* .. then no further RX happens.
* resetting the NIC works.
So, hm, what's causing this? And until that's found, can this trigger a cold reset, just in case?