Intermittent fan failure on Lenovo Yoga Slim 7 ProX (ACPI H_EC errors)

[domozurek]

System details

System:
Kernel: 6.17.8-arch1-1 arch: x86_64 bits: 64
Desktop: Hyprland v: 0.52.1 Distro: Arch Linux
Machine:
Type: Laptop System: LENOVO product: 82TK v: Yoga Slim 7 ProX 14IAH7
serial:
Mobo: LENOVO model: LNVNB161216 v: SDK0T76461 WIN
serial: UEFI: LENOVO v: HMCN50WW date: 06/28/2024
Graphics:
Device-1: Intel Alder Lake-P GT2 [Iris Xe Graphics] driver: i915 v: kernel
Device-2: NVIDIA GA107BM [GeForce RTX 3050 Mobile] driver: nvidia
v: 580.105.08
Display: wayland server: X.org v: 1.21.1.20 with: Xwayland v: 24.1.9
compositor: Hyprland v: 0.52.1 driver: X: loaded: modesetting,nvidia
dri: iris gpu: i915 resolution: 1: 2560x1440120Hz 2: 3072x1920120Hz
API: EGL v: 1.5 drivers: iris,nvidia,swrast
platforms: gbm,wayland,x11,surfaceless,device
API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: nvidia mesa v: 580.105.08
renderer: NVIDIA GeForce RTX 3050 Laptop GPU/PCIe/SSE2
Info: Tools: api: eglinfo,glxinfo gpu: gputop, intel_gpu_top, lsgpu,
nvidia-smi wl: wlr-randr x11: xprop,xrandr

What's wrong?

Description: Since the last update (to Omarchy 3.2.0), I've been experiencing intermittent issues where the laptop fans stop working completely. CPU temperatures rise to 90°C+ with no active cooling response.

Symptoms:

• Happens randomly, not consistent.
• Restarting the ideapad_laptop kernel module does NOT help.

Workaround: Suspending (s2idle) and resuming (or restarting) the laptop immediately fixes the issue and fans start spinning again.

Logs: I found specific ACPI errors in dmesg/journalctl pointing to the Embedded Controller and Fan Status (_FST) failing due to a missing symbol. This error correlates with the issue:

[176543.209727] ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PC00.LPCB.HEC.CFSP], AE_NOT_FOUND (20250404/psargs-332)
[176543.209735] ACPI Error: Aborting method \_SB.PC00.LPCB.H_EC.TFN1._FST due to previous error (AE_NOT_FOUND) (20250404/psparse-529)

I also see repeated NVIDIA power source change failures in the logs:

NVRM: rm_power_source_change_event: rm_power_source_change_event: Failed to handle Power Source change event, status=0x11

KWy8.log