Kobo Clara: Fails to change CPU frequency

Describe your issue

My Kobo Clara (board revision: 37NB-E60K00+4B0) is unable to change its CPU's frequency and is stuck on the lowest value.

What's the expected behaviour?

The CPU frequency changes in response to the governor, or to requests to manually set the frequency

What's the current behaviour?

The CPU frequency stays locked at the lowest value.

When checkingdmesg there's hundreds of this log:

[83791.375121] DCDC2: unsupportable voltage range: 1175000-1000000uV
[83791.375207] DCDC2: unsupportable voltage range: 1175000-1000000uV
[83791.375257] cpu cpu0: failed to scale vddsoc up: -22
[83791.375298] cpufreq: __target_index: Failed to change cpu frequency: -22

How to reproduce your issue?

What device are you using?

On what postmarketOS version did you encounter the issue?

• edge (master branch)

• v23.12

• v23.06 (supported until 2024-01-18)

• I confirm that the issue still is present after running sudo apk upgrade -a

On what environment did you encounter the issue?

Environments

• GNOME Shell on Mobile
• Phosh
• Plasma Mobile
• Sxmo (Wayland/Sway) Please post the output of sxmo_version.sh
• Other: console

How did you get postmarketOS image?

• from https://images.postmarketos.org
• I built it using pmbootstrap
• It was preinstalled on my device

What's the build date of the image? (in yyyy-mm-dd format)

2024-05-07

Additional information

This revision of the Kobo Clara has a different regulator, and was previously unable to boot, but this was resolved by @akemnade. Issue here

There may be something some other differences with this revision that are causing the frequency scaling to not work?