1d94aa369d
If the ioctl was defined without direction (e.g. _IO('o', 25)), then the arg as passed to vidioc_default was NULL instead of the original argument. Several ioctls in e.g. include/linux/dvb/video.h and audio.h use this type of ioctl to pass simple numerical values to the driver. Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>