View Full Version : [ubuntu] Hard freeze when connecting to secure wireless! (8.10 Intrepid, Lenovo R61, Intel)

January 26th, 2009, 09:43 PM
I just upgraded to Ubuntu 8.10 Intrepid Ibex (from Hardy Heron). I'm on a Lenovo R61 laptop with an Intel wireless card.

When I connect to a secure wireless network, it works for a short time.
But after about 5 minutes, my CPU usage shoots up to 100%. Soon afterwards, my laptop freezes completely!
I can only hold down the power button to turn it off. :(

(Also, a couple of times when my laptop was frozen, my wireless and caps-lock LEDs were blinking rhythmically. Does this indicate a kernel panic or something?)

If I can quickly run top before my laptop locks up, it shows me that the CPU-eating processes are:


Looking at my logs, /var/log/syslog, /var/log/messages, and /var/log/kernlog are all huge (>300 megabytes each!) and growing rapidly.
There are many many many repeats of the following:

Jan 26 14:09:53 rhyme kernel: [ 2750.930565] =======================
Jan 26 14:09:53 rhyme kernel: [ 2750.932978] bad: scheduling from the idle thread!
Jan 26 14:09:53 rhyme kernel: [ 2750.932982] Pid: 0, comm: swapper Not tainted 2.6.27-9-generic #1
Jan 26 14:09:53 rhyme kernel: [ 2750.932984] [<c037c4b6>] ? printk+0x1d/0x1f
Jan 26 14:09:53 rhyme kernel: [ 2750.932988] [<c0122b8a>] dequeue_task_idle+0x2a/0x40
Jan 26 14:09:53 rhyme kernel: [ 2750.932990] [<c012107f>] dequeue_task+0xcf/0x130
Jan 26 14:09:53 rhyme kernel: [ 2750.932993] [<c012112a>] deactivate_task+0x1a/0x30
Jan 26 14:09:53 rhyme kernel: [ 2750.932996] [<c037cad3>] schedule+0x4b3/0x790
Jan 26 14:09:53 rhyme kernel: [ 2750.932999] [<c01028cd>] cpu_idle+0xbd/0x140
Jan 26 14:09:53 rhyme kernel: [ 2750.933002] [<c036ee83>] rest_init+0x53/0x60

See the attachment for more details.

lspci -v gives me:

03:00.0 Network controller: Intel Corporation PRO/Wireless 4965 AG or AGN [Kedron] Network Connection (rev 61)
Subsystem: Intel Corporation Device 1110
Flags: fast devsel, IRQ 17
Memory at df3fe000 (64-bit, non-prefetchable) [size=8K]
Capabilities: <access denied>
Kernel driver in use: iwlagn
Kernel modules: iwlagn

I have no problems with my wired connection, or with wireless on an unsecured network.
(And I never had problems with any of this when I was using Hardy Heron.)

What's going on? Can someone help me?


January 27th, 2009, 07:55 PM
I am having the same problem on a Thinkpad T61p. It seems whenever I try to switch on/off the wireless for a few times(or just simply suspend/resume for a couple of times), something weird would happen.

January 27th, 2009, 08:02 PM
Further investigation reveals https://wiki.ubuntu.com/IntrepidReleaseNotes#System%20lock-ups%20with%20Intel%204965%20wireless

and https://bugs.launchpad.net/ubuntu/+source/linux/+bug/276990

So it looks like:
1) it is indeed a kernel panic, and
2) many other people with Intel wireless are experiencing the same problem.

Installing linux-backports-modules-intrepid, as suggested in the release notes, does not fix this problem for me. :(
I'll keep searching for more information.

January 28th, 2009, 01:13 PM
I also found another bug reporting regarding this issue:
#286285 (https://bugs.launchpad.net/ubuntu/+source/linux/+bug/286285), and according to this bug report:

***Important summary for those experiencing this bug***
Kernel versions where this bug is fixed:
1) 2.6.27-10 from intrepid-proposed

Kernel versions where this bug is NOT fixed (if you are running one of these, please upgrade to known working kernel):
1) 2.6.27-7 from intrepid
2) 2.6.27-9 from intrepid-updates and intrepid-security

A side note: I found there is 2.6.27-11 kernel in the Intrepid proposed repo, not sure if it is stable enough though.

January 28th, 2009, 07:58 PM
Good call! The bug you found is almost certainly the same one I'm getting.

I think 2.6.27-11 just came out on -updates this morning.
I'm using it right now, and it seems to be working; I haven't had a kernel panic yet. Tentative yay! :D

(Note: I also uninstalled linux-backports-modules-intrepid, as suggested on https://bugs.launchpad.net/ubuntu/+source/linux/+bug/286285, before applying the update.)