Hi Thibaut, Le Sunday 03 May 2015 à 00:33 +0200, Thibaut Verron a écrit :
I am a tumbleweed user, and I have recently (since 20150421 or 20150422) been having issues with my laptop's CPU overheating. Most of the times, the fan does not change speed when the temperature increases, and I cannot control its speed manually with pwm1_enable set to 1.
I reported it on the factory mailing list, and together we could rule out the possibility of a hardware failure (most likely dust on the fan). In particular, through some (seemingly) random changes, I could get the fan to work under manual control. This setting does not appear to be reliably persistent upon reboot, but it proves that the fan can still spin fast enough to cool down the CPU, when the OS has full control on its speed.
The setting I have to mess with to reactivate the fan when it stops working is the "thermal.off=1" parameter of the kernel. I would like to be more accurate, but I can't : in the past few days, I have "reactivated" the fan control twice, and as far as I can tell the procedure was not the same (and the same procedure did not yield the same consequences every time).
For reference, the factory thread is here: http://lists.opensuse.org/opensuse-factory/2015-04/msg00299.html
I read this thread in part, and here are a few random comments: * It is common that low fan speeds are reported incorrectly, this isn't specific to your laptop. The reason is that fan speed control is achieved by either PWM signal (most frequent) or by lowering the voltage. In both cases the rotation feedback signal gets harder to sense, and weaker signal translates to incorrect speed values being reported. While inconvenient, it should in general not result in any issue with thermal management. * If a recent kernel somehow messed up with your system, it is possible that the problem survives warm reboots, including switching to other operating systems or back to older kernels. I urge you to always _cold_ boot the machine before every test your perform. On laptops, cold booting may require unplugging the AC adapter AND removing the battery AND waiting for a couple minutes. * Your problems sound BIOS-related to me. In most BIOS there is an option to load setup or failsafe defaults. If you didn't try that yet, that would be worth trying. * If the previous advice doesn't help, it might be worth re-flashing the BIOS even if no new version is available. If the BIOS code was somehow corrupted, that would restore it. * When did you try manual fan speed control with pwm1_enable for the last time? If you normally don't need to do that, it is entirely possible that this has been broken for a longer time and you did not notice and this issue is unrelated with your current troubles. OTOH is the fan speed controller is hosed somehow, it wouldn't be all that surprising if that affects both manual and automatic modes. FWIW there was no recent change to the eeepc-laptop driver. As a closing note, I don't know how old your model is, but it should be noted that low-priced consumer hardware showing issues after 4-5 years is nothing out of the ordinary. This may not be what's happening here... but it may as well be "just" that.
In particular, I had gathered some information about my hardware on: https://gist.github.com/ThibautVerron/27da7b4da3940f9894c0
If some of this information is irrelevant, or some other is missing, don't hesitate to ask of course.
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