Comment 9 for bug 220857

I found a workaround to this problem.

First, I noticed the following.....

mk@aftermath:/lib/modules/2.6.24-16-generic/ubuntu/media$ find /lib/modules/`uname -r` | grep cx88xx.ko
/lib/modules/2.6.24-16-generic/ubuntu/media/cx88/cx88xx.ko
/lib/modules/2.6.24-16-generic/kernel/drivers/media/video/cx88/cx88xx.ko
mk@aftermath:/lib/modules/2.6.24-16-generic/ubuntu/media$ find /lib/modules/`uname -r` | grep saa7134.ko
/lib/modules/2.6.24-16-generic/ubuntu/media/saa7134/saa7134.ko
/lib/modules/2.6.24-16-generic/kernel/drivers/media/video/saa7134/saa7134.ko

The ubuntu kernel has its own separate copy of the cx88 and saa7134 modules! When we build new modules in the v4l-dvb repository from linuxtv.org, we are adding a second version of these modules.

There are copies of some other v4l modules, too:

mk@aftermath:/lib/modules/2.6.24-16-generic/ubuntu/media$ ls /lib/modules/`uname -r`/ubuntu/media
cx88 gspcav1 lirc ov511 quickcam saa7134 stk11xx usbvideo

It is ubuntu's version of these modules that is loading by default, and that is why we have the symbol version conflict with videobuf_foo.

To workaround the problem, delete the offending ubuntu driver from the directory above, then run "sudo depmod -a"

for example:

sudo rm -rf /lib/modules/`uname -r`/ubuntu/media/cx88
sudo rm -rf /lib/modules/`uname -r`/ubuntu/media/saa7134
sudo depmod -a

So, this issue does indeed seem to have been caused by bug #212100 's "fix".