[BUG REPORT] platform/x86/hp: hp-wmi: Fan control broken on HP OMEN 16-xf0xxx (board 8BCA, BIOS F.31)

[Kavan Bhavsar]

Subject: [BUG REPORT] platform/x86/hp: hp-wmi: Fan control broken on
HP OMEN 16-xf0xxx (board 8BCA, BIOS F.31)

Hi,

I'd like to report a regression in the hp-wmi driver affecting fan
speed reading and thermal profile control on my HP OMEN laptop.

HARDWARE:
  System:  HP OMEN by HP Gaming Laptop 16-xf0xxx
  Board:   8BCA v77.54
  BIOS:    Insyde F.31 (11/20/2025)
  CPU:     AMD Ryzen 7 7840HS w/ Radeon 780M Graphics
  GPU:     NVIDIA GeForce RTX 4060 Mobile
  RAM:     16 GB
  Kernel:  6.18.7-arch1-1 (Arch Linux)

ISSUE:
Fan speeds report 0 RPM and cannot be controlled via hp-wmi. The fans
are physically present and functional (they spin when controlled
directly via EC register writes), but the WMI interface does not
expose them correctly under Linux.

The following ACPI errors appear in dmesg on every boot:

  ACPI Error: Aborting method \_SB.WMID.GTPS due to previous error
(AE_NOT_FOUND)
  ACPI Error: Aborting method \_SB.WMID.RDCF due to previous error
(AE_NOT_FOUND)
  ACPI Error: Aborting method \_SB.WMID.WHCM due to previous error
(AE_NOT_FOUND)
  ACPI Error: Aborting method \_SB.WMID.WMAA due to previous error
(AE_NOT_FOUND)

WHAT I HAVE TRIED:
  - Loading hp-wmi and hp_omen_gaming_wmi modules
  - EC register write (modprobe ec_sys write_support=1, writing 0x31
to register 0x95) — this makes fans spin but RPM still reports 0
  - OmenCore v2.9.0 — detects hardware but reports 0 RPM
  - Building and loading the omen-fan-control patched hp-wmi driver —
driver registers as platform profile handler but fan speeds remain 0
  - Adding board 8BCA to omen_thermal_profile_boards[] manually and
rebuilding — platform profile handler registers successfully but fan
RPM still 0

ROOT CAUSE:
Board ID '8BCA' is not present in omen_thermal_profile_boards[] in
hp-wmi.c. Adding it causes the driver to register as a platform
profile handler, which is progress, but the underlying WMI methods
(GTPS, RDCF) still fail with AE_NOT_FOUND under BIOS F.31.

REQUEST:
  1. Please add board ID '8BCA' to omen_thermal_profile_boards[] in hp-wmi.c
  2. If possible, investigate the AE_NOT_FOUND errors for WMI methods
GTPS and RDCF under BIOS F.31 — this BIOS version appears to have
changed the WMI interface in a way that breaks fan reporting entirely
on Linux

I am happy to test any patches, provide additional logs (acpidump,
DSDT tables, etc.), or run any diagnostic commands needed.

Thank you for your time.

Kavan Bhavsar
kavanbhavsar6@xxxxxxxxx

Attachment: DSDT.dat
Description: Binary data