PMFE_RADIO_TOGGLE events

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

Hello,
pmf(9) defines a PMFE_RADIO_TOGGLE event, but it seems that actually nothing
listen to it.

On my previous laptop there is a switch, which turns on/off the transmitter
in hardware. The wpi(4) driver reports radio_button to userland and
powerd does see it (I use a script to stop/start wpa_supplicant).

On my new laptop there is a hotkey, which is now properly handled by
the wmi_dell driver. It injects a PMFE_RADIO_TOGGLE pmf event. But it seems
that nothing actually listen to this event, and powerd doens't see it either.
Note that this is just a hotkey, without software handling it doens't
have any effect on the radio transmitter state (I tried: pressing the
hotkey doens't stop wifi traffic).

Now I'm wondering what we should do with this event, and where it should be
handled. I can think of two solutions:
- handle it in kenrel: have all wifi and bluetooth interfaces listen to
  the event and act on it. One problem is synchronisation: the event
  doesn't carry information on radio state (on or off), so in machines
  with multiple radio, we could end up with some on and some off, and
  the event toggles everything so we can never have all radios on or off.
  So we'd need a global radio state.

- handle it in userland. This can give more flexibility on what and how
  to turn on/off. It may also be more difficult to control all the radio
  at once (how do we get a list of all radio interfaces in userland?)

Any idea on how to handle this ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
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