Laptop is a PackardBell EasyNote TK85. I don't know if it is a bug in NetworkManager or ath9k, but I suppose it's ath9k, I also tried with wicd, same problem. Problem exists since 11.04, I tried a lot to fix it. Tested on Ubuntu and Kubuntu.
UPDATE
Problem still persists in precise.
/UPDATE
PROBLEM:
From time to time the network becomes very slow, often it is like dead. After a few minutes it gets better again. If I restart networking sometimes it helps, sometimes not.
Solutions I tried:
- ath9k.conf in modprobe.d with nohwcrypt=1
- networkboot on top in BIOS (according to the internet sometimes it could help)
- compat-wireless via backport
- power management off
- blacklist acer_wmi, because it activates a second wlan-device
- deactivate BT to exclude interference
After all this trouble I decided to file a bug.
ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: network-manager 0.9.1.90-0ubuntu5.1
ProcVersionSignature: Ubuntu 3.0.0-16.28-generic 3.0.17
Uname: Linux 3.0.0-16-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
CRDA: Error: [Errno 2] Datei oder Verzeichnis nicht gefunden
Date: Thu Mar 1 11:25:53 2012
IfupdownConfig:
auto lo
iface lo inet loopback
InstallationMedia: Kubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
IpRoute:
default via 192.168.0.1 dev wlan0 proto static
169.254.0.0/16 dev wlan0 scope link metric 1000
192.168.0.0/24 dev wlan0 proto kernel scope link src 192.168.0.176 metric 2
NetworkManager.state:
[main]
NetworkingEnabled=true
WirelessEnabled=true
WWANEnabled=true
WimaxEnabled=true
RfKill:
0: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
WifiSyslog:
Status changed to 'Confirmed' because the bug affects multiple users.