Monitor mode not working for iwi(4) on 7.X

[Alexey Dokuchaev]

On Sat, Oct 09, 2010 at 08:46:41PM +0200, Bernhard Schmidt wrote:
> On Saturday 09 October 2010 08:02:39 Alexey Dokuchaev wrote:
> > Much better!  "airodump-ng iwi0" now sees stations in addition to APs,
> > which means it can utilize monitor mode.  "ifconfig iwi0 scan" however
> > does not work after that (and "list scan" returns no results) even if I
> > put adapter back to normal (from promisc and monitor modes) with
> > ifconfig(8).  kldunloading and loading module again fixes the issue.
> 
> Due to enqueueing the scan command in an infinite loop (yeah.. scanning 
> returns every frame, that's monitor mode for that device.. *sigh*) we might 
> increment a queue index but never actually dequeueing the command. On 'down' 
> we clear the command queue but not the indices resulting in the cur index
> not pointing to a filled entry. Attached patch should fix that.

It does, thanks!  "list scan" gets populated after I -mediaopt monitor
after scan; module reload is not required anymore.  Do I read you correctly
that seeing no results for "list scan" is OK while card is in monitor mode?

> On a side note, you should never be required to run 'ifconfig dev scan', 
> because after 'ifconfig dev up' the device is always in SCAN state (at least 
> in station mode). Using 'ifconfig dev list scan' is sufficient enough.

Certainly.  I was meant to say that "list scan" returned no results, and
"forcing" the scan (despite that background scan is in progress) would
never return either.

> It might be possible with lots of ugly hacks to get that device sending some 
> kind of frames, 'injecting' those frames via net80211 shouldn't be that hard. 
> At least the code is there according to comments in ieee80211_output.c. I do 
> not consider this worth the effort though, if someone wants to work on that, 
> let me know.

I might want to take a look when time permits.

> > Apart from that, machine seems stable, and monitor mode is fixed.  Thanks
> > a lot!
> 
> You're welcome :)

Hope to see the final set of patches in RELENG_7 soon.  ;-)

./danfe