Whenever a device node is created some attributes are also created for you.
If you look in /sys/class/video4linux you see the devices. Go into e.g.
-video0 and you will see 'name', 'debug' and 'index' attributes. The 'name'
-attribute is the 'name' field of the video_device struct. The 'debug' attribute
+video0 and you will see 'name', 'dev_debug' and 'index' attributes. The 'name'
+attribute is the 'name' field of the video_device struct. The 'dev_debug' attribute
can be used to enable core debugging. See the next section for more detailed
information on this.
video device debugging
----------------------
-The 'debug' attribute that is created for each video, vbi, radio or swradio
+The 'dev_debug' attribute that is created for each video, vbi, radio or swradio
device in /sys/class/video4linux/<devX>/ allows you to enable logging of
file operations.