Hi Andrea, On 09/28/2018 03:03 PM, Andrea Merello wrote: > I do often use this driver, and I'm interested in working on it for preventing it from being removed. > > I can perform functional test with my HW (usb microscope) on a kernel from current media tree (anyway currently it works on my box with a pretty recent kernel). > > How much effort is expected to be required to port it to vb2? I'm currently hacking on another (recent) v4l2 subdev driver, but my wknowledge of the v4l2/media framework is far from good.. If someone give me some directions then I can try to do that.. > cpia2 has its own streaming I/O implementation. This should be completely replaced by vb2. Easiest is to look at a fairly recent usb driver like usbtv to see how it is done there. The vb2 API is fairly clean (see include/media/videobuf2-core.h), but switching to vb2 is a big-bang action, you can't switch a little bit, it is all or nothing. So that makes this a big unreadable patch in the end. The v4l2-compliance utility is your friend when testing this. If you would be willing to work on this, then it's easiest if you use the #v4l channel on freenode irc to ask questions (which I am sure you'll have). It's a fair amount of work, I'm afraid. It would probably take me 1-2 days to convert depending on how nice the rest of the cpia2 driver is. Regards, Hans
