it's not just 11b/11g.
The following was happening, and it's quite .. annoyingly grr-y.
* create vap, setup wpa_supplicant with no bgscanning, etc - there's
no call to ieee80211_media_change, so vap->iv_des_mode is
IEEE80211_MODE_AUTO;
* do ifconfig wlan0 scan - same thing, media_change doesn't get called,
iv_des_mode stays as auto.
* But then, run wpa_cli and do 'scan' - it'll do a media change.
* if you're on 11ng, vap->iv_des_mode gets changed to IEEE80211_MODE_11NG
* Then makescanlist() is called. There's a block of code that gets
called if iv_des_mode != IEEE80211_MODE_AUTO, and it does this:
if (vap->iv_des_mode != IEEE80211_MODE_11G ||
mode != IEEE80211_MODE_11B)
continue;
mode = IEEE80211_MODE_11G; /* upgrade */
* .. now, iv_des_mode is not IEEE80211_MODE_11G, so it always runs
'continue'
* .. and thus the scan list stays empty and no further channel
scans occur. Ever.(1)
If you then disassociate and try associating to something, your
scan table has likely been purged / aged out and you'll never
see anything in the scan list.
(1) You need to do 'ifconfig wlan0 mode auto' or just destroy/re-create
the VAP to get working wireless again.
Tested:
* iwn(4) - intel 5300 wifi; STA mode; using wpa_supplicant; bgscan
enabled -and- wpa_supplicant scanning.
Thanks to:
* Everyone who kept poking me about this and wondering why the hell
their wifi would eventually stop seeing scan lists. Grr.
I eventually snapped this evening and dug back into this code.
9c75c3d4ba