@all: I just now see this right before the kernel panic:
btrfs: Unknown parameter 'x-systemd.device-timeout'
I added that after this hint I got from @SteeledPick when my system hang at “Starting switch root”.
Could that be the root cause? I’ll temporarily remove that, do a system upgrade, reboot and will let you know.
Edit: no, that wasn’t it
This time I got “Please add correct root option” or something? Here is my current refind-linux.conf:
"Boot with standard options" "quiet zswap.enabled=0 nowatchdog splash rw rootflags=subvol=/@ root=UUID=0b4778d2-2b54-48a9-a184-b2a951e9335a resume=UUID=14b5e04a-1c2f-41c2-a2a5-cd9ffe1ec2a0"
"Boot to single-user mode" "quiet zswap.enabled=0 nowatchdog splash rw rootflags=subvol=/@ root=UUID=0b4778d2-2b54-48a9-a184-b2a951e9335a resume=UUID=14b5e04a-1c2f-41c2-a2a5-cd9ffe1ec2a0" single
"Boot with minimal options" "ro root=/dev/nvme0n1p3"