On Mon October 15 2012 13:35:45 Hans Verkuil wrote:
During the Plumbers Conference a few weeks ago we had a session to resolve V4L2 ambiguities. It was very successful, but we didn't manage to tackle two of the harder topics, and a third one (timestamps) cause a lot of discussion on the mailinglist after the conference.
So here is the list I have today. Any other ambiguities or new features that should be added to the list?
I've got another:
Right now there are no standard ioctls that one could call for a v4l-subdev node to discover whether the device node is really a subdev node. For other v4l nodes we have QUERYCAP, but that's not available for subdev nodes.
I propose that QUERYCAP support is added (and will be required) for subdev nodes. The capabilities field will be set to V4L2_CAP_SUBDEVICE only (at least for now). All other fields of v4l2_capability are just as valid for subdevs as they are for normal v4l devices.
Regards,
Hans