ath9k roaming for no obvious reason

[Howard Chu <hyc@symas.com>]

I've been seeing this for a couple of months now, and updating to the latest 
wireless-testing git hasn't improved things:

 >>>
Apr 20 07:31:12 violino NetworkManager: <debug> [1240237872.002673] 
periodic_update(): Roamed from BSSID 00:12:17:26:56:10 (HighlandSun) to (none) 
((none))
Apr 20 07:31:18 violino NetworkManager: <debug> [1240237878.004208] 
periodic_update(): Roamed from BSSID (none) ((none)) to 00:12:17:26:56:10 
(HighlandSun)
Apr 20 07:32:12 violino NetworkManager: <debug> [1240237932.003138] 
periodic_update(): Roamed from BSSID 00:12:17:26:56:10 (HighlandSun) to (none) 
((none))
Apr 20 07:32:18 violino NetworkManager: <debug> [1240237938.004280] 
periodic_update(): Roamed from BSSID (none) ((none)) to 00:12:17:26:56:10 
(HighlandSun)
<<<

This is on an HP dv5z laptop, lspci shows
08:00.0 Network controller: Atheros Communications Inc. AR928X Wireless 
Network Adapter (PCI-Express) (rev 01)

It's about 10 feet from a Linksys WRT54G and there's nothing blocking the line 
of sight. I'm running a 2.6.29.1 kernel at the moment; used the 
compat-wireless git to build the wireless stack.

At random intervals (15-20 minutes or so) it loses the association completely 
and NetworkManager asks me to re-authenticate. This behavior seems to have 
gotten worse in the current snapshot. Has anyone else seen this, any ideas?
-- 
   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
   Chief Architect, OpenLDAP  http://www.openldap.org/project/