[coreboot] fan too slow ; speeds incorrect? ; here's how i enabled the x60t fan

[Andrew Engelbrecht]

the fan of my x60 tablet wasn't working under coreboot. i got it
spinning by adding the following:[1]

$ cat /etc/modprobe.d/thinkpad-fan.conf
options thinkpad_acpi fan_control=1

(then reboot.) you can then see something like the following here:

$ cat /proc/acpi/ibm/fan
status:		enabled
speed:		2488
level:		auto
commands:	level <level> (<level> is 0-7, auto, disengaged, full-speed)
commands:	enable, disable
commands:	watchdog <timeout> (<timeout> is 0 (off), 1-120 (seconds))

$ cd /sys/class/hwmon/hwmon1/device ; ls


problem: fan speeds appear to be incorrect. my fan also seems too slow.

i've been tinkering with thinkfan and fancontrol, but they don't survive
a full stress test.[2]

does anyone else have slow fan problems? is it something i should
replace? i may have mildly borked my EC by flashing the EC for an x60
then the correct x60t EC over it. any advice is welcome.

thanks,
-andrew


p.s. (it seems like kernel fan control is disabled without the module
option, when using coreboot or the oem bios. the vendor bios gives some
auto fan action, but it's often too slow.)

[1] source: https://bbs.archlinux.org/viewtopic.php?pid=1169414#p1169414
[2] resource: https://wiki.archlinux.org/index.php/Fan_Speed_Control