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* hp-wmi: WHCM AE_AML_OPERAND_TYPE and fan init -22 on HP OmniBook 5 16-ag1xxx (board 8DF4)
@ 2026-10-11 16:03 Lorenzo Collevecchio
  2026-10-11 22:45 ` Armin Wolf
  2026-10-12  4:03 ` Krishna Chomal
  0 siblings, 2 replies; 9+ messages in thread
From: Lorenzo Collevecchio @ 2026-10-11 16:03 UTC (permalink / raw)
  To: platform-driver-x86; +Cc: linux-acpi, linux-hwmon

Hello,

I am seeing hp-wmi fan interface failures on an HP OmniBook 5
16-ag1xxx. This is not a gaming model.

Hardware:
  product_name: HP OmniBook 5 Laptop 16-ag1xxx (16-AG1002SL)
  board_name:   8DF4
  BIOS:         F.12, 04/10/2026 (no newer firmware listed on LVFS for
this machine)
  Kernel:       7.2.9-2-cachyos (also tested 6.18.55-2-cachyos-lts;
ACPICA 20250807 vs 20260408)

Symptoms:
1. At boot, \_SB.WMID.WHCM (called via WMAA) fails three times with
   "AE_AML_OPERAND_TYPE: Needed [Buffer/String/Package], found
[Integer]" while resolving operands for [Index].
2. Immediately afterwards: "hp-wmi hp-wmi: Failed to apply initial fan
settings: -22".
3. Later: "Attempt to CreateField of length zero" in \_SB.WMID.WQBC
and WQBE (AE_AML_OPERAND_VALUE).
4. hp_wmi still registers as a platform profile handler (quiet
balanced performance).
5. /sys/devices/platform/hp-wmi/hwmon/*/ contains only pwm1_enable
(rw); there is no pwm1 and no fan1_input.
6. On the LTS kernel the same WHCM error repeats about every 2.2 s
while something polls the hp hwmon device (277 times between 551 s and
1165 s uptime).
7. ACPI thermal: "Invalid critical threshold (-274000)" and "No valid
trip points!" for thermal zone TSZ0.

Fan behaviour:
- acpi_fan (acpi-fan PNP0C0B, "Using Microsoft fan extensions")
exposes fan1_input. It sometimes shows about 2400 RPM and sometimes 0
RPM.
- The fan works normally under Windows on the same machine.
- I once saw the CPU around 95 C with the fan apparently stopped on
Linux; I have not been able to reproduce it yet and am collecting a
temperature/RPM log.

I suspect the WMI query path the driver uses for fan settings is not
implemented by this firmware, so hp-wmi should probably not attempt it
on board 8DF4. I would be glad to test patches or provide acpidump
output, WMI GUID listings or any other data.

Thanks,
Lorenzo

^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2026-10-13  9:33 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-10-11 16:03 hp-wmi: WHCM AE_AML_OPERAND_TYPE and fan init -22 on HP OmniBook 5 16-ag1xxx (board 8DF4) Lorenzo Collevecchio
2026-10-11 22:45 ` Armin Wolf
2026-10-12  4:03 ` Krishna Chomal
2026-10-12  8:08   ` Lorenzo Collevecchio
2026-10-12 15:24     ` Krishna Chomal
2026-10-12 16:04       ` Lorenzo Collevecchio
2026-10-12 17:49         ` Krishna Chomal
2026-10-12 19:34           ` Lorenzo Collevecchio
2026-10-13  9:32             ` Lorenzo Collevecchio

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