Thinkfan on Thinkpad E14 Gen 2

limmor1 commented 3 years ago

Hi! Thinkfan seems to be a great program, but I am having one issue - even when I set the fan to work at a single speed for all temperatures I am getting periodic drops in RPM. The fan is running at the specified level, but then periodically switches to "auto" and the RPMs drop for a short moment and then resume again.

Things I tried:

changing thinkfan -s 5 to different periodicity. The periodicity depends on the time, e.g. if I set "1", the RPMs drop more often. If I set "15" the drops are less frequent.
polled/proc/acpi/ibm/thermal to verify that my temperature sensor does not register any drops or spikes (I polled with bash loop, so there there is a limit to how frequently I can poll, but I did not see any sudden changes in temperature)
polled/proc/acpi/ibm/fan to verify that the fan reports the same level all the time, except during the drop it changes to "auto".

My setup:

Thinkpad E14 Gen 2.
Linux Mint, kernel 5.8.0-40 to 43.
thinkfan 0.9.3.2

/etc/thinkfan.conf:

tp_fan /proc/acpi/ibm/fan
tp_thermal /proc/acpi/ibm/thermal (10 0 0 0 0 0 0 0)
(5, -32767, 32767)  # (also tried (127, 0, 256) in case that matters, but same effect

/etc/default/thinkfan: DAEMON_ARGS="-q -b 5.0 -s 5"

vmatare commented 3 years ago

This sounds a lot like this issue: https://github.com/vmatare/thinkfan/issues/114#issuecomment-757535018

That would mean the problem lies with either the thinkpad_acpi kernel module or with the laptop's embedded controller firmware. A possible workaround might be to have thinkfan disable the watchdog. Currently that's not allowed because it's potentially dangerous if thinkfan or your entire userspace freezes.

limmor1 commented 3 years ago

Thanks! This made me aware that apt repository has a very old version of thinkfan. After building new version I no longer experience the issue.

vmatare / thinkfan

Thinkfan on Thinkpad E14 Gen 2 #127