cpu fan at maximum after suspend to memory

[Petr Kopač]

Ubuntu 8.10, kernel 2.6.27-11
When I suspend my computer (Intel Core 2 Duo e8400 @ 3.6 GHz) to memory and wake it up, the cpu fan, which is set to Silent mode (low RPM) in BIOS, is rotating at maximum, which is quite loud. I think it is supposed to return to normal state. It's not because some crashed application would take too much processor power, its usage is circa at 0-5 %. The folders /proc/acpi/thermal_zone/ and /proc/acpi/fan/ are empty. But it's probably something with those ACPI things. Any suggestions? Thx

Note: Bug # 37132 seemed similar, but I've got another piece of hardware etc.

[VladimirCZ (vlabla)]

I have the same problem with Ubuntu 10.04 64-bit, kernel 2.6.32-22-generic, fully updated + HP Probook 4510s, Celeron(R) Dual-Core CPU T3000 @ 1.80GHz, Mobile Intel Graphics Media Accelerator 4500MHD integrated graphics, Product Code VQ540EA#AKB.

[VladimirCZ (vlabla)]

I have found that this happens only with a default value of the BIOS option "Fan always on while connected to an AC
outlet" = Enable. If disabled the fan starts resuming at hight speed (BIOS?), but soon it slows down (linux?). It is surprising, that such a value is pre-set on a machine delivered originally with a SLED linux installation. Anyway, I will test also behaviour when on battery ...

[Dave (david-ayres3)]

I also run an HP Probook 4510s and can confirm this issue. If you unplug the power cord, the fan will reduce to the normal rate.

[František Zatloukal (zatloukal-frantisek)]

Can you control fan speed through terminal(manual is here: http://tuxtweaks.com/2008/08/how-to-control-fan-speeds-in-ubuntu/ )?

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.