I've installed Ubuntu 12.04.5 LTS on an (quite old) IBM ThinkPad T40.
Connecting to the internet using LAN works perfectly fine, but as soon as I "Enable Wireless" in the Network Manager, choose a (WPA2-encrypted) network, enter a password (doesn't matter whether it is correct or not) and hit the "Connect" button, the laptop becomes unbearably slow and unusable. The problem persists after a reboot.
The laptop can be made reusable by deleting Network Managers's configuration file using Ubuntu's Recovery Mode: root@laptop:~# rm /etc/NetworkManager/system-connections/NameOfNetworkIWantToConnectTo.
Here are some details about my wifi adapter.
me@laptop:~$ lspci | grep Wireless
02:02.0 Ethernet controller: Qualcomm Atheros AR5211 Wireless Network Adapter [AR5001X 802.11ab] (rev 01)
me@laptop:~$ rfkill list all
0: tpacpi_bluetooth_sw: Bluetooth
Soft blocked: yes
Hard blocked: no
1: phy0: Wireless LAN
Soft blocked: yes
Hard blocked: no
Unblocking phy0 using sudo rfkill unblock 1 didn't help (edited on 2016-07-14).
Googling has brought me to some hypotheses on the problem but not yet to a solution:
- The driver might be buggy
- There might be an issue with the kernel or in the interaction of the driver and the kernel: when the OS froze, I was able to switch to the console and something like "task wpa_supplicant blocked for more than 120 seconds" appeared on screen ⇒ kernel panic?
wpa_supplicantmight be the cause of the problem- There was one post on deactivating the hardware encryption of the wireless adapter. But it was for another device and I didn't know how to adapt that for my case.
- As it's an old device with an old processor (Intel Pentium M), the installation of Ubuntu was made using the forcepae option. Might this cause the problem?
- Installation crashed for later versions of Ubuntu (USB drive was deactivated during installation which consequently led to reading errors)
Previously, installing all updates led to a crashed dependency stack because of some kernel-related packages. Therefore, I've installed all updates except for those affecting the kernel.
Do you have any ideas on how I could solve the problem? If yes, I'd kindly ask you to share them with me. ^-^
Best wishes