Usually I get my userspace pointers to work with data after ioctl DQBUF. When buffer is not used anymore (processing is finished) I will call ioctl DQBUF.
Is there an easy way (not consuming to much time) to check the status of a buffer? So whether it is queued or dequeued?
Of course I could collect this information in userspace but I learned that keeping same info at different position is not a good idea.