Recent fan control problem.

petelewis · 2010-06-27 13:22:04

Hi,

Since a recent update - I'm sorry I'm not sure when, but I think the last couple of weeks - I've noticed that my laptop (Samsung Q35) has been getting rather hot. Occasionally it turns itself off since it hits a critical temperature.

I've not changed anything that I've had installed on this laptop power-wise since I first installed Arch a couple of years ago, so something must have changed.

There is *a* fan on, but it used to increase the fan / fire up a second (not sure) when the temperature went up, usually triggered by compiling things etc. Now, it doesn't seem to be able to do this, and instead I get the overheating. Here's some info:

% lspci
00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03)
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03)
00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 02)
00:1c.0 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 1 (rev 02)
00:1c.1 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 2 (rev 02)
00:1d.0 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #1 (rev 02)
00:1d.1 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #2 (rev 02)
00:1d.2 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #3 (rev 02)
00:1d.3 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #4 (rev 02)
00:1d.7 USB Controller: Intel Corporation 82801G (ICH7 Family) USB2 EHCI Controller (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev e2)
00:1f.0 ISA bridge: Intel Corporation 82801GBM (ICH7-M) LPC Interface Bridge (rev 02)
00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE Controller (rev 02)
00:1f.3 SMBus: Intel Corporation 82801G (ICH7 Family) SMBus Controller (rev 02)
02:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG [Golan] Network Connection (rev 02)
05:09.0 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev b4)
05:09.1 FireWire (IEEE 1394): Ricoh Co Ltd R5C552 IEEE 1394 Controller (rev 09)
05:09.2 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 18)
05:09.3 System peripheral: Ricoh Co Ltd R5C592 Memory Stick Bus Host Adapter (rev 09)
05:09.4 System peripheral: Ricoh Co Ltd xD-Picture Card Controller (rev 04)

% cat /proc/acpi/thermal_zone/TZ00/temperature
temperature:             87 C

% sensors
acpitz-virtual-0
Adapter: Virtual device
temp1:       +87.0°C  (crit = +95.0°C)                  
temp2:       +87.0°C  (crit = +95.0°C)                  

coretemp-isa-0000
Adapter: ISA adapter
Core 0:      +82.0°C  (high = +100.0°C, crit = +100.0°C)  

coretemp-isa-0001
Adapter: ISA adapter
Core 1:      +84.0°C  (high = +100.0°C, crit = +100.0°C)

% cat /proc/acpi/fan/FAN0/state
status:                  off

I have the coretemp module loaded (as recommended by lm_sensors), but it doesn't give me any output at all in dmesg.

I've tried echoing things to /proc/acpi/fan/FAN0/state but it just gives me permission denied.

I'm a bit worried that it's not getting turned on automatically any more. Should this be managed by the BIOS (there are no power management options in there)? Or by software? I found the fan speed control page on the wiki, but that seems more like a bit of hacking to get extra fine grained control, rather than just making the thing work in the first place.

As I said, this worked before a week or two ago. Now I'm afraid to compile anything since it might fry my hardware! :-/

Thanks in advance, and please let me know if more info would help diagnose the problem.

Pete.

petelewis · 2010-06-27 13:27:50

Additional info after finding this related post: http://bbs.archlinux.org/viewtopic.php?pid=782442

% pwmconfig

# pwmconfig revision 5770 (2009-09-16)
This program will search your sensors for pulse width modulation (pwm)
controls, and test each one to see if it controls a fan on
your motherboard. Note that many motherboards do not have pwm
circuitry installed, even if your sensor chip supports pwm.

We will attempt to briefly stop each fan using the pwm controls.
The program will attempt to restore each fan to full speed
after testing. However, it is ** very important ** that you
physically verify that the fans have been to full speed
after the program has completed.

/usr/sbin/pwmconfig: There are no pwm-capable sensor modules installed

Do I now need a kernel module that I didn't before? I should point out though that I've never used this program to control the fan speed before, it just seemed to happen and I'd never thought about it.

Has something changed in the kernel, or perhaps with acpid? (I'm running acpid).

Thanks.

petelewis · 2010-06-27 16:01:03

Okay, I've made some progress. I realised that the cpu frequency governor wasn't running, since I didn't have cpufreq in DAEMONS. Starting that meant that the CPUs were throttled back somewhat and the temperature dropped significantly. I've been keeping a graph of the core temperature (the scale isn't meaningful) but take a look at this if you want to see the effect this had! http://petesodyssey.org/files/temperature.png

So, this has fixed the problem with overheating, but I do find it interesting that the system isn't able to cool itself enough if the CPU is running at full speed for a reasonable amount of time. Is this normal? I'm guessing this means that there's still a problem with the fan.

/proc/acpi/fan/FAN0/state still says the fan is off, so I'm guessing the OS isn't aware of the fan and hence has no ability to control it. (Perhaps this is what the error given by pwmconfig in my previous post is pointing to).

Arch Linux

#1 2010-06-27 13:22:04

Recent fan control problem.

#2 2010-06-27 13:27:50

Re: Recent fan control problem.

#3 2010-06-27 16:01:03

Re: Recent fan control problem.

Board footer