Asus Zenbook Embedded Controller Struggles

in linux, embedded-controller, fedora, note-to-self, mental-health

As a follow-up to my other post about corrupted EC/firmware state on both AMD and INTEL devices during/after updates, I want to focus on the seemingly random EC state corruptions that I only experience on the Intel platform (ultra 9 285h).

The Situation

I rarely reboot my laptop, basically only to apply updates. On my new intel zenbook I noticed that after some time (10-24 hours) the EC state will go corrupt. The issue is subtle but indicates like this:

• reboots take forever, even reaching LUKS screen is >1min
• waking up from suspend is slow
• the login screen transition from user-select to password-input is choppy
• howdy stops working
• touchpad will drop random inputs
• using keyboard hotkeys (brightness up/down etc) hangs the system for ~10sec
• generally bad performance, weird frequency scaling of CPU etc

The immediate fix is of course to just push and hold the power button for a minute or so but I want to find a solution that prevents this from happening.

During the hangs, dmesg produced no output whatsoever. This is significant: it means the freeze did not occur in kernel space, but inside the EC/ACPI firmware itself - at a layer the kernel cannot observe or log. The EC reset being the only possibility to recover confirms the EC entered a corrupted state.

Approach #1: WAPF Setting

Claude 4.6 suggested that I change the WAPF ("WMI ACPI Power Feature") value from 0 to 4 to avoid corrupting the EC state by pressing the FN+F-Keys although I doubt that this causes the issue. I think it is more likely that the weird FN+F-key behaviour is a symptom than the cause. Either way, here are the commands I used to set that value from 0 to 4:

# before
cat /sys/module/asus_nb_wmi/parameters/wapf
# change from current value to 4
echo "options asus_nb_wmi wapf=4" | sudo tee /etc/modprobe.d/asus-nb-wmi.conf
sudo rmmod asus_nb_wmi && sudo modprobe asus_nb_wmi
# after
cat /sys/module/asus_nb_wmi/parameters/wapf

Coping with the issue regardless of a fix

I was thinking of returning the laptop because I was really frustrated with the issue but the retailer I purchased it from declined to take it back with the reasoning that the issue is extremely hard to reproduce and apparently does not occur when running the only supported OS: windows.

Asus may have some windows-driver that constantly resets the EC to avoid such issues but using windows is absolutely out of the question for me.

Maybe I am running into a hardware-too-new-issue with the kernel here, as I have before and maybe this will fix itself down the road.

Next steps

• take a photo of the errors that happen during boot before boot once I enter the corrupted state
• track how of then error occurs and if there is software-related action that may trigger it