[ltp] 2.6 kernel kills the CPU fan

[Richard Neill]

>> Helen Borrie wrote:
>>
>>> Hello all,
>>> I'm trying to track down a solution on my TP390E to a problem that 
>>> seems rife:  that Linux causes the CPU fan to stop as soon as you 
>>> begin to boot the OS.  

> And, yes, the machine is getting hot enough to put itself into suspend 
> (which one can't get out of) and to not want to complete POST when 
> rebooted after doing this.  I seem to get about 30 minutes "life" before 
> this happens;  and need about 10 mins for cool-down.  The bottom of the 
> case feels hand-hot when this occurs (i.e. about 60-65 Celcius) and I 
> think I can sometimes smell hot fumes (the latter could be my el cheapo 
> gel mousepad, though, it's pretty smelly, even at 5 Celcius).

That's definitely a bug. There is no way that this should be deliberate.
At least it's an Intel CPU - and so it shuts down when overheated. AMDs 
(at least in some cases), just catch fire!

However, on reflection, the BIOS shouldn't let the OS mess up the fan 
speed anyway. [Eg, what happens when the OS crashes?]

If it is the OS, are you running APM or ACPI?  If you run either the apm 
or acpi commands, what do you get?

> 
> The respective home dirs of the logged in users, i.e. root and one 
> other, contained bunches of coredump files.  Unfortunately, I wouldn't 
> have a clue about interpreting them.

You can ignore them - they won't tell you anything useful. The crash was 
caused by an overheated CPU, so the coredump info is irrelevant.

However, when testing, it would be safer to:

init 1    (or shut down as many services as you can)
umount home
mount -o remount,ro /

That way, when it crashes, it won't harm your data.  Or boot into single 
user mode with "linux single" at the lilo command prompt.

Running "yes" will put the CPU at full load, to help test.

> 
> I will take your advice and get hold of the Knoppix distro.  Actually, I 
> may be able to test the Knoppix behaviour as I have the Ulitmate Boot CD 
> here.

Good luck. Knoppix is useful, since it does give you an extra datapoint 
for very little effort!

Best wishes

Richard

P.S. You could also check for an updated BIOS.