Comment 22 for bug 1460447

This issue, or variant thereof, has been observed on Ubuntu 20.04 and Linux Mint 20.
I'm not 100% sure yet but it SEEMS to be affecting systems with a floppy drive.

Can end up with bootup-messages:-

[timestamp] Btrfs loaded, crc32c=crc32c-generic
Scanning for Btrfs filesystems
[timestamp] floppy0: floppy_queue_rq: timeout handler died. old request running

removing 'btrfs-progs' (which then removes from initrd) works around the issue reliably.
I need to double-check, i think kernel command line modprobe.blacklist=floppy can also workaround issue.
Last I checked, I didn't find this to be specific to a particular kernel/series.

Certainly experienced this on totally different hardwre, e.g. an intel core-2-duo in compaq Dx2300, but also on a completely different HP motherboard AMD64 machine/chipset. From what I can see this is not particular hardware specific either!.