Thank you for the quick reply @MaLd0n!
I dont know what is my problem exactly, my special keys (fn+f3 and fn+f4) controls brightness perfectly, but everytime I reboot from Windows, it doesn't work anymore (if I hold power button for 30secs to reset my EC, or something ... then it works again, but always after windows stops working).
I tried this kext but reboots always when I try to load it. I dont use any special SSDT or DSDT patches for this. I tried booting with "-v" and "-brkeysdbg" for debug output, but I got nothing meaningful. Just freezes while booting with this kext.
TY
https://github.com/lonacluka/HP-EliteBook-840-G6-Hackintosh
