[ltp] Kick up the Fan - R50e Fan problems

[Thomas Renninger]

Thomas Renninger wrote:
> Thomas Renninger wrote:
>>Hi,
>>
>  ...
>>a friend has a R50e and sever fan problems.
>>
>  ...
> As far as I can say these fan/heat problems only appear in recent
> kernels on a large number of Thinkpads, is that right?
> 
It seems as if this is not right.

Some Thinkpads seem to have a poor thermal design and get hot quite quickly.
I expect that this and newer embedded controller firmware updates (check version with dmidecode)
make things even worse:
_______________
Symptom corrected by version 3.03 - 1RHT70WW
Reduced Fan noise in some models
_______________

The ondemand governor in current kernels is also broken in respect to thermal management.
I could partly fix it (in rare cases it could happen that when passive cooling is left, the
frequency stucks at lowest speed, but this should also be fixed soon).

For now people with critical shutdown problems should go for the userspace governor and
a cpufreq daemon.
There the max frequency is lowered until the temperature sub-ceeds the passive trip point
again. That should work well.

Fiddling around with this I also noticed that fan speed should be able to be set to full-speed with most
Thinkpads.
If I saw things right, you can disable, set automatic and full-speed. Possibly the automatic mode
could be influenced with different values, not sure, the fan speed always was around 3200-3700.

I will send a patch to be able to set the fan to full-speed seperately (you gain some more time you can use the
laptop on highest frequency).


       Thomas

BTW: While debugging this I noticed that the powersave daemon, I stated in my last mail, has a bug
in overwritting the trip points, I'll fix that on Monday.