Hi Bart, On Friday 05 March 2010 23:28:22 Bart Koppe wrote: > (sorry for my empty reply just before this one) > > Hi Paulo, > > I got vloopback running in the first place with this link. I remember > insmod did not work, but 'make install' and then 'modprobe vloopback' > did. So I didn't bother with it, untill after installing uvc-video it > stopped working. > Maybe i got the same message as now, but i don't remember. > # insmod vloopback.ko > insmod: error inserting 'vloopback.ko': -1 Unknown symbol in module > > In the readme of vloopback they mention this error and the solution: > > Solution : You must load videodev module : > 'insmod videodev ; insmod ./vloopback.ko' > > Also they mention: > > To compile and install : > make ; su - ; make install > /sbin/modprobe videodev > /sbin/modprobe vloopback > > > But I now don't have videodev and it is not included in > svn co http://www.lavrsen.dk/svn/vloopback/trunk/ vloopback
The videodev.ko module provides the V4L2 core. If you're running a distro kernel the module was shipped with your kernel. For backward-compatibility reasons (to make the latest driver work on older kernels), the uvcvideo driver ships with a copy of the whole V4L2 subsystem source. When installing the uvcvideo module, you've also installed the latest version of the V4L2 core and other V4L2 drivers. > Basically I have no clue why it ever worked, I had no videodev module > installed unless it came with another software package, could that be? > I also remember having videdodev in the last few days, so maybe somehow > I removed it.. I guess installed uvc-version over it, and then with > 'make rminstall' i deleted it. Does that make sense? It could make sense yes. > Trying to install the uvc-video version of videodev (I already ran 'make > minstall', then 'make') I get: > # insmod v4l/videodev.ko > insmod: error inserting 'v4l/videodev.ko': -1 Unknown symbol in module This kind of message is caused by incompatibilities between driver versions. Basically, the videodev.ko module you're trying to load depends on other modules, but the version of those modules that are already loaded came from your distro and are not recent enough. To solve this problem, you need to either: - install the V4L2 subsystem that comes with uvcvideo, replacing the one that came with your distro (you might need to remove the distro one manually, as the new one might probably installs in a new location), or - load all the required V4L2 modules in order using insmod (in this case you would need to load v4l/v4l2-compat-ioctl32.ko before loading v4l/videodev.ko). The first solution is easier. > When i run just 'make install' as in the uvc-video readme, it installs > and I can 'modprobe videodev'. > Then back to my vloopback source and > # insmod vloopback.ko > insmod: error inserting 'vloopback.ko': -1 Unknown symbol in module This is because the vloopback.ko module has been compiled against your kernel distro, while the loaded videodev.ko module came with uvcvideo and is more recent. > When I do 'make install' instead of insmod I get the same old error again > # modprobe vloopback > FATAL: Error inserting vloopback > (/lib/modules/2.6.26-2-686/kernel/drivers/misc/vloopback.ko): Unknown > symbol in module, or unknown parameter (see dmesg) > > Any idea? To solve your problem, you need to recompile vloopback against the uvcvideo tree. -- Regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list Linux-uvc-devel@lists.berlios.de https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
