Sorry for just disappearing / not answering.
My grandmother has gotten bowel cancer and is going into surgery tomorrow, so I have helped her a lot and haven’t had time to write here.
I don’t have time to try to submit patches to either the kernel or OpenWrt for the next few weeks either - can someone else here please do it for me ? 
I’m sorry to hear that. Unfortunately I also don’t have much time right now to pick up your work. Anyone?
Thank you for your Work!
Don’t care about the project so much, care about your grandmother 
.
I believe this is not a 3-PIN PWM fan. The third pin from the fan is output to the host for reporting fan speed.
Do you have a way to measure PWM signal? If so, do you get pulses from the 3rd PIN of this fan in your experiment? I would like some assurance that this fan is indeed a 3-pin PWM fan…lol
Update
@Hypnotize confirms the fan is indeed PWM fan in this post
I want to have this question also in this chat:
I think it is really important that Frank and/or dangowrt gets your code into the actual Openwrt snapshot. I was really happy to hear about your progress. Some people will not find this chat, this is why it is so important to get it into the snapshot!
How I can update kernel on this one to 6.1.8 ? Because :
Version: 6.1.86-r1
Size: ~180.00 KiB installed
Dependencies:
kernel VERSION INCOMPATIBLE
kmod-hwmon-core INSTALLED
Description
Kernel module for NVM Express solid state drives directly connected to the PCI or PCI Express bus.
The installed version of package kernel is not compatible, require 6.1.86~0dc73eff…-r1 while 6.1.82~c31a377a…-r1 is installed.
I guess you use openwrt snapshot,right? Please make own topic as this is for bpi-r4 fan setup,not nvme.
I’m using compiled image from Hypnotize. So exactly with PWM fan patch. But if I want keep this build and add as example nvme, I cannot due to compatibility.
Independ from this it is unrelated to cpu fan setup…you can link to the image and maybe hypnotize build an image to include the nvme part or upgrade to actual openwrt where you maybe can install additional packages
setup 1: at /BPI-R4-OPENWRT-V21.02/target/linux/mediatek/mt7988/base-files/etc/init.d/fanspeed if [ ! -d /sys/devices/platform/pwm-fan ]; then exit 0 fi
setup 2: at //home/jiang/BPI/BPI-R4-OPENWRT-V21.02/target/linux/mediatek/mt7988/base-files/sbin/fan-speed
USE this file and replace it fan-speed (5.7 KB)
Then rebuild
or edit and replace
setup 1: the file in /etc/init.d/fanspeed. find and edit it
setup 2 : replace fan-speed with my file in /sbin/
Where can we set these values before compiling?
example: /sys/class/thermal/thermal_zone0/trip_point_1_temp
I cannot for my life find that info, and it’s not in the notes and patches on getting the pwm working.
The trip-point temperatures are already set in mt7988a.dtsi so not part of the patches…
Got it, thank you. Now to move on to other items on my list.
This looks like the r3 heatsink…i saw it on aliexpress but more expensive than r4 heatsink
Indeed apparently it’s the R3 heatsink, but hey if it works it doesn’t matter.
Yes thats the same i have and it is working with my latest patches for dts. Daniel will add them to openwrt too.
PWM is working now? Sweet.
