Comment 0 for bug 1940553

Still gathering more information about this, but here's what we've noticed so far. We saw several new test failures happening on rpi devices that seemed pretty random, wifi tests failing on rpi4, playback device detection failing on armhf, etc. We also noticed on most armhf devices and some arm64 devices, our testsuite didn't run the cpu scaling test because it failed to find /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors

This is on uc18 images, and the current set of snaps where we can reliably reproduce it is:
Snaps currently installed:
Name Version Rev Tracking Publisher Notes
bluez 5.48-3 286 latest/stable canonical* -
checkbox-snappy 18.16 2102 18/stable ce-certification-qa devmode
checkbox18 1.22 1685 latest/stable ce-certification-qa -
core 16-2.51.3 11425 latest/stable canonical* core
core18 20210816 2140 latest/beta canonical* base,ignore-validation
docker 19.03.13 801 latest/stable canonical* -
pi 18-1 100 18-pi/stable canonical* gadget
pi-bluetooth 1.0 4 latest/stable cwayne18 -
pi-kernel 5.4.0-1042.46~18.04.3 338 18-pi/stable canonical* kernel
snapd 2.51.3 12705 latest/stable canonical* snapd

I was still able to reproduce it by rolling back core18 to earlier revisions. I'm unable to rollback the kernel because of the recent gadget change. However, these errors didn't happen when we tested the current pi-kernel in beta.

Juergh did some excellent investigation and found that it's loading the wrong dtbs.