ath9k: scanning kills unicast

["Richard Schütz" <r.schtz@t-online.de>]

When I receive data with the highest possible speed in my 802.11g 
network and simultaneously scan for available networks (NetworkManager 
does this all the time in the background) ath9k enters a strange state: 
unicast data transfer is stalled, but broadcast is still working. This 
state lasts for a while. Then it ends after deauthentication (Reason: 6) 
and reauthentication. ATH_DEBUG_FATAL logs nothing.


$ lspci -nn|grep Atheros
05:00.0 Network controller [0280]: Atheros Communications Inc. AR9285 
Wireless Network Adapter (PCI-Express) [168c:002b] (rev 01)

$ dmesg|grep -i ath
ath9k 0000:05:00.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16
ath9k 0000:05:00.0: setting latency timer to 64
ath: EEPROM regdomain: 0x65
ath: EEPROM indicates we should expect a direct regpair map
ath: Country alpha2 being used: 00
ath: Regpair used: 0x65
ieee80211 phy0: Selected rate control algorithm 'ath9k_rate_control'
Registered led device: ath9k-phy0::radio
Registered led device: ath9k-phy0::assoc
Registered led device: ath9k-phy0::tx
Registered led device: ath9k-phy0::rx
ieee80211 phy0: Atheros AR9285 Rev:2 mem=0xffffc90012260000, irq=16

$ uname -r
2.6.37-ARCH