Just a short question about v4l. Why the ioctl "VIDIOCGCHAN" is defined as IOWR(read and write)? It seems just getting data from device. Background: I'm hacking Jeroen Vreeken's vloopback device driver version 0.90. In this driver, ioctls defined IO_IN (writes) supposes that the source of the pipe (called pusher) does not rewrite the arguments of ioctl. But, In the process of VIDIOCGCHAN, the pusher has to write some data to the arguments. Kentarou Fukuchi
