fan stops spinning after booting into linux

startover · 01-26-2011, 06:46 AM

I have got an Acer 3820T laptop. Among many problems that it seems to have with linux, the most critical one is that when I boot into linux, the fan stops spinning. I have already verified that the relevant modules are loaded into the kernel,

Code:

~$ modprobe --first-time -a processor thermal fan acpi-cpufreq coretemp
Password: 
WARNING: Module processor already in kernel (builtin).
WARNING: Module thermal already in kernel (builtin).
WARNING: Module fan already in kernel (builtin).
WARNING: Module acpi_cpufreq already in kernel.
WARNING: Module coretemp already in kernel.

BIOS does not have any fan relevant option either.

Running sensors-detect I would get

Code:

Sorry, no sensors were detected.
This is relatively common on laptops, where thermal management is
handled by ACPI rather than the OS.

Code:

$ uname -a
Linux acer.timelinex 2.6.35.10-74.fc14.x86_64 #1 SMP Thu Dec 23 16:04:50 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux

startover · 01-26-2011, 08:33 AM

update:

Although when I want to insert modules processor, thermal, fan into the kernel it gives the warning that the module is already in the kernel (builtin), when I run the commands

Code:

$ lsmod | grep processor
$ lsmod | grep thermal
$ lsmod | grep fan

I get nothing in the output.

I am confused in here, how can this happen that I get two contradicting outputs!

frieza · 01-26-2011, 10:32 AM

if the machine isn't suffering from overheating issues then I wouldn't worry too much, perhaps the fan is merely shut down to save power on the battery. I've seen that on some laptops, the fan will only run when the laptop is hot enough to need the fan to cool it, otherwise it stays off. Either way have you tried looking at energy saving settings in either bios or Linux?

startover · 01-26-2011, 02:25 PM

Quote:

Originally Posted by frieza

Either way have you tried looking at energy saving settings in either bios or Linux?

There is no energy savings setting in the BIOS. How can I find the energy saving settings in Linux, there is nothing I can find about the fans. I am running a Fedora 14 with Gnome desktop.

linus72 · 01-26-2011, 03:29 PM

I had to compile a custom kernel for my Toshiba 7000CT PentiumII for the fans to work with fnfx on ARCH linux

TobiSGD · 01-26-2011, 04:06 PM

Quote:

Originally Posted by startover

update:

Although when I want to insert modules processor, thermal, fan into the kernel it gives the warning that the module is already in the kernel (builtin), when I run the commands

Code:

$ lsmod | grep processor
$ lsmod | grep thermal
$ lsmod | grep fan

I get nothing in the output.

I am confused in here, how can this happen that I get two contradicting outputs!

These outputs are not contradicting. lsmod lists the loaded modules, but processor, thermal and fan are compiled into the kernel (a.k.a. builtin) and therefore are not loaded as modules.

My laptop also stops the fan, if the temperature of the CPU is below a certain value (for me it is 50° C). Have a look at your temperatures, maybe there is nothing wrong.

startover · 01-26-2011, 06:10 PM

Quote:

Originally Posted by TobiSGD

My laptop also stops the fan, if the temperature of the CPU is below a certain value (for me it is 50° C). Have a look at your temperatures, maybe there is nothing wrong.

according to acpi -ti :

Code:

Thermal 0: trip point 0 switches to mode critical at temperature 96.0 degrees C
Thermal 1: trip point 0 switches to mode critical at temperature 88.0 degrees C
Thermal 1: trip point 1 switches to mode passive at temperature 85.0 degrees C

A couple of times I noticed that the sensors indicate a temperature of 86.0 degrees (just above the passive trip point) and the fan is not yet working.
Can it have any thing to do with acpi trip points?
Does this configuration of trip points seem correct to you?

TobiSGD · 01-26-2011, 06:22 PM

At first, I find the value of 85° for enabling the fan a bit high, and I think that only a gap of 3° to switch to critical mode is a very small gap. On my laptop I have much more trip points, almost every 10°.
May be that your ACPI-tables in BIOS are incorrect, I have already heard somewhere that this may be the case, but only for Linux, they work on Windows. Sadly, I think I am stuck here and can't help anymore.