kern/154157: [ath] Monitor mode is broken on at least the AR9280

[Adrian Chadd]

>Number:         154157
>Category:       kern
>Synopsis:       [ath] Monitor mode is broken on at least the AR9280
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Jan 20 07:20:08 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Adrian Chadd
>Release:        HEAD r217622
>Organization:
Xenion Pty Ltd
>Environment:
FreeBSD-head r217622, i386 eeepc of some description
>Description:
Monitor mode with if_ath on at least the AR9280 is broken. It hasn't been tried on earlier cards.

After a short period, frames stop being received.
>How-To-Repeat:
# ifconfig wlan0 create wlandev ath0 wlanmode monitor
# ifconfig wlan0 channel 6
# ifconfig wlan0 up
# tcpdump -ni wlan0 -y IEEE802_11_RADIO

[wait a short period]

>Fix:
Sometimes bouncing the interface is enough. Other times unloading/reloading the interface is enough.

>Release-Note:
>Audit-Trail:
>Unformatted: