Hello Gregoire,
Are you sure you have used the v4l2 "videodev.o" (backported from 2.5) that comes from the "build-2.4" directory from the "dvb-kernel" cvs tree?as already repported with older ac and older CVS of dvb-kernel, same Oops with 2.4.21-rc7-ac1:
Please don't CC the linux kernel mailing list the next time, since this is a dvd only issue. Thanks!Grégoire