Comment # 1 on bug 100666 from Sergey Kochneff

You should try kernel 4.12. There is some progress with pwm1_enable: now we
have not only "1" which is manual control but "0" (full speed) and "2" (this
should be FW control, although it doesn’t look so for me: fans are still
spinning and pwm1 reads 0 or 122-124 randomly). Still have to use userspace
control (mode "1").