Fan control completely non-functional on Linux due to broken ACPI tables - OMEN 16-xf0xxx (Board 8BC

[Sreyas_28]

Product: OMEN by HP Gaming Laptop 16-xf0xxx
Board ID: 8BCA
BIOS Version: F.29 (latest available, updated from F.20 - issue persists on both)
OS: Arch Linux, Kernel 6.19.10-arch1-1
CPU: AMD Ryzen 9 7940HS
GPU: NVIDIA RTX 4070 Laptop

ISSUE:
Fan control is completely inaccessible on Linux due to broken ACPI tables in the BIOS. The symbol [\_SB.PEP.DETY] is missing from the ACPI tables, which causes all WMI thermal management methods to fail.

ERRORS FROM DMESG:
ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PEP.DETY], AE_NOT_FOUND
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)
ACPI Error: Aborting method \_SB.WMID.WQBC due to previous error (AE_AML_OPERAND_VALUE)
ACPI Error: Aborting method \_SB.WMID.WQBE due to previous error (AE_AML_OPERAND_VALUE)

WHAT THIS MEANS:
The hp_wmi kernel module loads successfully and registers hotkeys, but cannot register platform_profile (thermal/fan control) because the underlying ACPI WMI methods abort due to the missing PEP.DETY symbol.

STEPS TO REPRODUCE:
1. Boot any Linux distribution on OMEN 16-xf0xxx
2. Run: sudo dmesg | grep -i "WMID\|PEP"
3. All WMI thermal methods will show AE_NOT_FOUND errors
4. /sys/firmware/acpi/platform_profile does not exist
5. Fan speed reads 0 RPM at all times regardless of CPU/GPU load
6. No fan control software works (tested: nbfc-linux, fancontrol, hp_wmi patch)

IMPACT:
Under heavy workloads (running LLM models on RTX 4070), GPU reaches 76°C+ causing thermal throttling and display flickering. Since fans cannot be controlled or even monitored from Linux, there is no way to run fans more aggressively to prevent throttling.

WHAT WORKS ON WINDOWS:
OMEN Gaming Hub correctly controls fans and thermal profiles on Windows, proving the hardware is fully capable. The issue is exclusively in the BIOS ACPI implementation for Linux.

REQUESTED FIX:
Please add the missing [\_SB.PEP.DETY] symbol to the ACPI tables in a future BIOS update, or properly expose the WMI thermal management interface for Linux. Board 8BCA should also be added to the supported board list in the hp_wmi kernel driver alongside 8BAD and 8E35.

This issue affects all Linux users on the OMEN 16-xf0xxx and likely other recent OMEN models with board 8BCA.

[Jerry_57]

Hi @Sreyas_28,

Welcome to the HP Support Community.

Thank you for posting your query. I will be glad to help you.

I understand you are facing an issue with the fan on your OMEN 16-xf0xxx.

May I know if you are using the Linux OS on your laptop?

 Note: HP supports only Windows OS.

Take care and have a good day.

Jerry_57
HP Support

[Sreyas_28]

Thank you for your response. I understand HP officially supports
Windows only. However, this is a BIOS/ACPI bug - the symbol
\_SB.PEP.DETY is missing from the ACPI tables which violates the
ACPI specification. This affects ALL operating systems that follow
the ACPI standard. I have documented this technically here:
Board 8BCA (OMEN 16-xf0xxx) - platform_profile not registered due to missing \_SB.PEP.DETY in ACPI t...

Could this be forwarded to your BIOS engineering team?

[Jerry_57 · Accepted solution]

Hi @Sreyas_28,

Thank you for your response.

Please install Windows 11 on your laptop and then check if the same error appears.

Regards
Jerry_57
HP Support

[Raghavendrakk]

I fixed the HP OMEN 16 fan control issue on Linux/Ubuntu dual-boot systems.

I built a working fix and pushed it to GitHub since many people are facing the same problem.

You can install and run it from here:
https://github.com/Raghavendrak81622/hp-wmi-omen-fix