Monitor mode is flaky on iwm(4). E.g. switching the device back into
regular operation doesn't always work. I have even seen laptops lock
up while running iwm in monitor mode.
This diff makes our monitor mode code implementation closer to iwlwifi:
- use a distinct station ID for monitor STA
- set station type to "general purpose" instead of "link"
- use "any address" (zero) as station address instead of broadcast address
- use the inject monitor Tx queue, and do not enable regular Tx queues
- accept multicast frames
With this I can reliably switch back and forth between BSS and monitor modes.
Not sure yet if lockups have really disappeared, but this should be an
improvement over our current monitor mode code in any case.
Tested on 7265 and 8265.
I am not sure if the non-DQA case really works but that is not important
since it only matters for outdated firmware.