Ribadisco che:
"Now /etc/modprobe.d/ is processed by modprobe. This means that
/etc/modprobe.conf and /lib/modules/modprobe.conf are not needed
anymore and update-modules is now a no-op. Executable scripts in
/etc/modprobe.d/ are not supported anymore.
/etc/modprobe.conf will be removed or moved to /etc/modprobe.d/."

ma a quanto pare il kernel e modconf cercano comunque il file modprobe.conf.