bin/46932: wpa_cli reports signal levels as 0

[diro%nixsyspaus.org@localhost]

>Number:         46932
>Category:       bin
>Synopsis:       wpa_cli reports signal levels as 0
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Sep 10 04:20:01 +0000 2012
>Originator:     diro%nixsyspaus.org@localhost
>Release:        NetBSD 6.0_RC1
>Organization:
>Environment:
System: NetBSD gift 6.0_RC1 NetBSD 6.0_RC1 (GIFT) #6: Sat Sep  1 04:44:23 UTC 
2012  root@gift:/usr/obj/sys/arch/amd64/compile/GIFT amd64
Architecture: amd64
Machine: amd64
>Description:

% dmesg | grep iwn
iwn0 at pci2 dev 0 function 0: vendor 0x8086 product 0x4232 (rev. 0x00)
iwn0: interrupting at ioapic0 pin 19
iwn0: MIMO 1T2R, MoW, address $MAC
iwn0: 11a rates: 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
iwn0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
iwn0: 11g rates: 1Mbps 2Mbps 5.5Mbps 11Mbps 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 
36Mbps 48Mbps 54Mbps

> scan
04:06:17.763: OK

> scan_results
04:06:21.825: CTRL-EVENT-DISCONNECTED bssid=$BSSID reason=0
04:06:21.825: CTRL-EVENT-BSS-ADDED 7 $BSSID2
04:06:21.825: CTRL-EVENT-BSS-ADDED 8 $BSSID3
04:06:21.825: CTRL-EVENT-BSS-ADDED 9 $BSSID4
04:06:21.825: CTRL-EVENT-SCAN-RESULTS
04:06:21.825: Trying to associate with $BSSID (SSID='$SSID' freq=2462 MHz)
04:06:21.825: Associated with $BSSID
04:06:21.825: bssid / frequency / signal level / flags / ssid
$BSSID       2462    0       [WPA-PSK-TKIP+CCMP][ESS] $SSID
$BSSID2       2462    0       [WEP][ESS]      $SSID2
$BSSID3       2412    0       [WEP][ESS]      $SSID3
$BSSID4       2462    0       [ESS]   $SSID4

04:06:26.829: WPA: Key negotiation completed with $BSSID [PTK=CCMP GTK=TKIP]
04:06:26.829: CTRL-EVENT-CONNECTED - Connection to $BSSID completed (reauth) 
[id=7 id_str=]
>How-To-Repeat:
        Either use wpa_supplicant from base or build it from pkgsrc (using 
2012Q2
here), run wpa_cli or wpa_gui, and check the signals.
>Fix: