Asus_wmi sysfs writes block indefinitely on kernel 7.0.3+ — ROG Flow Z13 GZ302EA (Strix Halo)

General
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Hardware:

  • Device: ASUS ROG Flow Z13 GZ302EA
  • CPU: AMD Ryzen AI MAX+ 395 (Strix Halo, Zen 5)
  • GPU: Radeon 8060S (integrated, gfx1151)
  • RAM: 64GB unified
  • OS: CachyOS (KDE Plasma 6.6.4, Wayland)

Symptom:
On kernels 7.0.3 through 7.0.10, any write to /sys/devices/platform/asus-nb-wmi/ blocks for exactly 60 seconds before returning Input/output error. Affected paths include throttle_thermal_policy, ppt_pl1_spl, and ppt_pl2_sppt. The path /sys/firmware/acpi/platform_profile is also affected.

This causes G-Helper (and any tool that writes to these paths on startup) to render the system completely unresponsive. The process cannot be killed even with kill -9 as it is stuck in uninterruptible kernel I/O.

Working kernel: 7.0.2-2-cachyos — all sysfs writes complete instantly.

Regression: Clean bisect between 7.0.2 and 7.0.3. This appears related to the upstream asus_wmi thermal profile initialization regression (commit b012170fed) which was reported on the kernel mailing list in December 2024 and reverted by Arch Linux for their 6.12.1 kernel. It appears this regression or a variant of it is still present in the CachyOS 7.0.x kernel for Strix Halo hardware specifically.

Is there any chance of including a fix or revert for this in the CachyOS 7.0.x kernel patches?

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Update: bisected further. On the same machine, same userspace, same cmdline: vanilla Arch linux 7.0.11-arch1-1 — sysfs write returns instantly. linux-cachyos 7.0.11-1 — blocks ~60s then EIO. Also reproduced on linux-cachyos-lts 6.18.34-1. Conclusion: the regression is in the CachyOS patchset (introduced between your 7.0.2-2 and 7.0.3 builds), not upstream. Suspect the asus-linux/asus_armoury patches.