cooler in laptop model Lenovo N100 doesn't work after resuming from hibernate state

I can confirm that this is also an issue in the Lenovo 3000 N100 with the (I think) Intel duo T2300 and the latest Feisty upgrades. I can't confirm whether this was present in Dapper (new laptop) but it has been occurring from the end of March - it's not related to a recent upgrade.

Hibernate works just fine, but upon resume the fan does not work and the CPU overheats regularly (causing the laptop to shut down).

Normal operating temperature BEFORE hibernation tends to be about 48C, and when I jack up the CPU to 100% and watch some flash videos that rises to 61C. The fan kicks in above 50C and the temperature does not rise above 61C (in my brief tests). After turning down CPU back to ~0%, temperature returns to 48C within 20 seconds.

AFTER hibernate, jacking CPU usage up to 100% and watching flash videos rapidly sent the temperature above 70C, and no fan. The temperature continued to rise about 1 degree every few seconds, so I stopped the test (otherwise it would have shut down). The temperature has remained constant at 76C for about 10 minutes now since conducting the test.

The following outputs are taken after hibernation, as is the lsmod attachment (note that the fan and thermal modules are loaded, even after resume from hibernation).

[robert@mujuno: ~] cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 14
model name : Genuine Intel(R) CPU T2300 @ 1.66GHz
[snip]

[robert@mujuno: ~] uname -a
Linux mujuno 2.6.20-15-386 #2 Sun Apr 15 07:34:00 UTC 2007 i686 GNU/Linux

[robert@mujuno: ~] cat /proc/acpi/thermal_zone/TZ00/*
cooling mode: active
<polling disabled>
state: ok
temperature: 76 C
critical (S5): 102 C
passive: 87 C: tc1=0 tc2=4 tsp=4 devices=0xde07c6bc 0xde07c6a8

Bugs 6729 and 7122 on the acpi-support bugzilla seem related, as does bug 72360 on Launchpad:

https://bugs.launchpad.net/ubuntu/+source/acpi-support/+bug/72360
http://bugzilla.kernel.org/buglist.cgi?short_desc_type=allwordssubstr&short_desc=fan&product=ACPI&long_desc_type=allwordssubstr

The problem with some HP laptops appears to have been the firmware, and the fan being reported as always on (or some incorrect signal like that). My BIOS is from September 2006 and I see the Lenovo website has an updated BIOS from 28 February 2007. Unfortunately the IBM website is inaccessible at the moment, so I can't test their update - will post here when I have tried that out.

i have applied the latest firmware (upgraded 61ET32WW to 61ET35WW) and the fan still does not work after resume from hibernate. Latest firmware information is from

http://www-307.ibm.com/pc/support/site.wss/document.do?sitestyle=lenovo&lndocid=MIGR-67008

I've noticed the same on my ASUS A6000U.

[Expired for linux-source-2.6.20 (Ubuntu) because there has been no activity for 60 days.]

My battery has now failed due to this overheating problem. I'm adding a comment and marking this bug as a duplicate of other (confirmed) bugs.