I'm having trouble with the thinkpad_acpi module on my Thinkpad T400. While the processor temperature can vary, depending on the CPU activity, from 40 to 85 deg. Celsius, my fan speed remains almost constant, in the range of 2600-3000 rpm. I was expecting the fan to speed up as the temperature rises, but it's not happening.
Before digging deeper into why it doesn't work as one would expect, I tried to check if manually increasing the fan speed works. According to this README, I should be able to control the fan speed by writing level [1-7]
to /proc/acpi/ibm/fan
, but I get the "Invalid argument" error whatever the value.
I realize this is an obscure problem, but may be someone has an idea what might be valid arguments. Here are some of my attempts:
# cat /proc/acpi/ibm/fan
status: enabled
speed: 2966
level: auto
# echo 5 >/proc/acpi/ibm/fan
bash: echo: write error: Invalid argument
# echo 'level 5' >/proc/acpi/ibm/fan
bash: echo: write error: Invalid argument
# echo 'enable' >/proc/acpi/ibm/fan
bash: echo: write error: Invalid argument
# echo 'level auto' >/proc/acpi/ibm/fan
bash: echo: write error: Invalid argument