9.2.2 Fan control

[errcl65]

I use passive cooling, but have a fan.   Prior to 9.2.2 my config.txt was setup
to turn the fan off.   I guess the new release wrote new stuff in config.txt.

VCGENCMD measure_temp give me 47C (under 50C).

With 55,50,75, the fans still runs all the time.   My reading, fan should off and
run only at "75" speed between 50-55C

For now I turned the fan off with pinctrl FAN_PWM op dh

[Tim Curtis]

My understanding is that for 55,50,75 when the temp exceeds 55 the fan turns on at speed 75 and stays on until the temp goes back down to 50.

The dtparam looks like this
dtparam=fan_temp0=55000,fan_temp0_hyst=5000,fan_temp0_speed=75

Here's the documentation I used. There was one other article but I can't find the link.
https://github.com/raspberrypi/firmware/...EADME#L271
https://www.raspberrypi.com/documentatio...-pi-5-fans