Red Hat Bugzilla – Bug 129413
CPU fan never shuts down on ThinkPad A31p
Last modified: 2015-01-04 17:08:28 EST
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040510 Description of problem: The CPU fan on my A31p never stops running. It runs 24/7 at full speed, no matter what the cpu load or temperature. I suspect it is an ACPI issue since acpi doesn't seem to detect the cpu fan at all. The path: /proc/acpi/fan/, is completely empty. I've seen other laptops have some kind of sensor information in there. The problem is more evident when the laptop runs on battery, the fan runs at full speed all the time and thus lowers battery life by 10%! Running winblowz on the same machine shows that the cpu fan only comes up at high cpu temperature. Version-Release number of selected component (if applicable): kernel-2.6.7-1.494.2.2 How reproducible: Always Steps to Reproduce: 1. boot Fedora 2. listen to the fan spin 3. forever... Actual Results: fan spins constantly Expected Results: fan spins only when cpu is at a high temperature Additional info: Hardware: IBM ThinkPad A31p 1 gig ram 80 gig hdd 2xDVD drives ATI FireGL 7800 M7 Intel Pentium 4 2.0ghz Software: Fedora Core 2 kernel 2.6.7-1.494.2.2
Same with FC3. Also tested with other kernels... Probably simething in ACPI ....
Yup, indeed. Maybe the IBM Power Management driver for Windowz takes care of that under windoze. In that case, the cpu fan is software controlled and not controlled by the BIOS or some hardware temperature thingy. If the fan is controlled via software, then this is a dead issue. IBM never releases any hardware information for their ThinkPads. One such example is the lm_sensors util that kills ThinkPads, IBM never helped solve the problem.
An update has been released for Fedora Core 3 (kernel-2.6.12-1.1372_FC3) which may contain a fix for your problem. Please update to this new kernel, and report whether or not it fixes your problem. If you have updated to Fedora Core 4 since this bug was opened, and the problem still occurs with the latest updates for that release, please change the version field of this bug to 'fc4'. Thank you.
The ibm-acpi project has managed to control the CPU fan, thus making it possible to turn off and on the fan based on the CPU temperature.