V4L/DVB (10252): v4l2 doc: explain why v4l2_device_unregister_subdev() has to be called.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Hans Verkuil 2009-01-15 06:09:05 -03:00 committed by Mauro Carvalho Chehab
parent 6ca187abb2
commit f5360bdc55

View file

@ -340,6 +340,12 @@ Make sure to call v4l2_device_unregister_subdev(sd) when the remove() callback
is called. This will unregister the sub-device from the bridge driver. It is
safe to call this even if the sub-device was never registered.
You need to do this because when the bridge driver destroys the i2c adapter
the remove() callbacks are called of the i2c devices on that adapter.
After that the corresponding v4l2_subdev structures are invalid, so they
have to be unregistered first. Calling v4l2_device_unregister_subdev(sd)
from the remove() callback ensures that this is always done correctly.
The bridge driver also has some helper functions it can use: