Created attachment 861923 [details]
Kernel Bootup screen

After upgrade from 15.3, kernel version 5.14.21.15400.24.21.2 repeatedly hangs
for 2-3 mins (see attached photo), then udev doesn't appear to have worked
properly as in at least 1 case, bttv pci card not recognized (in dmesg) though
working module config exists from 15.3.

modprobe -r bttv then modprobe bttv once booted, and card is recognised.

Revert to kernel 5.14.21.15400.22.1 and it doesn't halt + udev works as
expected, card is recognised using existing unchanged config.

Hardware is an HP 8300 CMT, with a Kodicom 4400R multi bttv card.
100% repeatable