[Bug 221149] hp-wmi: Fan control fails and RPM always reads as zero on HP OMEN 16-wf1xxx (Board 8C76)

bugzilla-daemon
2026-02-27T12:14:41Z

Enderlava (Jie7172585@gmail.com) changed:

What |Removed |Added
----------------------------------------------------------------------------
CC| |Jie7172585@gmail.com

--- Comment #2 from Enderlava (Jie7172585@gmail.com) ---
Hi Krishna,

I successfully applied your patch to the 7.0-rc1 source and recompiled the
kernel. Here are the test results for Board 8C76:

1. Registration: success
`dmesg` shows `hp_wmi: Registered as platform profile handler`. The previous
ACPI/WMI errors (error 0x6) are completely gone.

2. Fan Control (Write): success
Writing 0 to `pwm1_enable` successfully ramps the fans to maximum speed, and
writing 2 returns them to auto mode. The physical fan control works perfectly.

3. Thermal Profile / Power Limits: success
Switching to the performance profile successfully raises the PL1 limit to 130W,
unlocking the CPU:
Profile: low-power -> PL1: 55 W | PL2: 130 W
Profile: balanced -> PL1: 55 W | PL2: 130 W
Profile: performance -> PL1: 130 W | PL2: 130 W

4. Fan RPM Reading (Read): fails
Although the fans physically spin up and the control works, reading the hwmon
nodes (`cat fan1_input`) constantly returns 0 RPM.