Playing around with scantv and xawtv and the analog module of my
Fujitsu-Siemens ff card, I got the following oops on kernel 2.6.6.
The reason is that a call to format_by_fourcc() returns NULL. To me it
looks like scantv does a VIDIOC_STREAMON ioctl, and the pixelformat is
set to something not supported. As to why pixelformat is set to
something the driver doesn't like and why it needs to BUG_ON that
condition, I've only been able to make bad guesses...
The BUG_ON() is there, because the format should be valid at every time.
After the driver has been loaded, a default format is used and
afterwards, setting an unsupported format should be prohibited.