rpi4 POE+ Hat fan control

[trumee]

Hello,
I have the new rpi poe+ hat and its fan is working with the linux-raspberrypi4 kernel. Unfortunately, the fan comes on even at low temperatures.

I saw this post for raspbian which suggests that the fan speed can be controlled. How can we do it in ALARM running aarch64 and linux-raspberrypi4 kernel?

[graysky]

Did you try the method outlined in the link you cited? What worked? What didn't work?

[trumee]

I set the following,

$this->bbcode_second_pass_code('', '
$ cat /boot/config.txt
# See /boot/overlays/README for all available options

dtoverlay=vc4-kms-v3d
initramfs initramfs-linux.img followkernel
# PoE Hat Fan Speeds
dtparam=poe_fan_temp0=50000
dtparam=poe_fan_temp1=60000
dtparam=poe_fan_temp2=70000
dtparam=poe_fan_temp3=80000
')

The fan is not turning on. I can see '/sys/class/thermal/cooling_device0/cur_state' changing between 1,2 and 3 though. I dont know whether there is a way to check the fan rpm.