Missing module in initramfs : haw to know which one, and how to add it.

[Erwan David]

Hi,

Some times ago I went from modules=most to modules=dep in initramfs, 
because /boot was too small.

the machine is a laptop usually standalone but from time to time 
connected to a dock with external USB keyboard

Today at boot : external keyboard worked for grub, did not work for 
entering LUKS key, and works once system is started. This I deduce I 
need some supplementary module(s) in the initrd. Is there a way to 
identify those modules and add them ?