lsmod
Module                  Size  Used by
st                     68736  0
sr_mod                 42916  0
cdrom                  64784  1 sr_mod
ipv6                  464336  32
apparmor              102332  0
aamatch_pcre           34720  1 apparmor
loop                   41376  0
dm_mod                115288  3
ibmveth                42600  0
sg                     69064  0
ibmvscsic              46952  3
pdc202xx_new           32176  0 [permanent]
sd_mod                 41264  5
scsi_mod              221512  5 st,sr_mod,sg,ibmvscsic,sd_mod

If the module you wanted listed above wasn’t in use, you could unload and load it to refresh:

modproble $modname ; modprobe $modname