diff options
| author | Hans Verkuil <hverkuil@xs4all.nl> | 2009-03-14 08:28:45 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2009-03-30 12:43:22 -0300 |
| commit | ae6cfaace120f4330715b56265ce0e4a710e1276 (patch) | |
| tree | ed01c11218132e92ce8fe4872fe26c572c3c8842 /Documentation/video4linux/v4l2-framework.txt | |
| parent | 6273fda6e32e2cd9a478545d0cbc15ac497b1f4b (diff) | |
V4L/DVB (11044): v4l2-device: add v4l2_device_disconnect
Call v4l2_device_disconnect when the parent of a hotpluggable device
disconnects. This ensures that you do not have a pointer to a device that
is no longer present.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation/video4linux/v4l2-framework.txt')
| -rw-r--r-- | Documentation/video4linux/v4l2-framework.txt | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index 4207590b2ac..a31177390e5 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt @@ -105,6 +105,17 @@ You unregister with: Unregistering will also automatically unregister all subdevs from the device. +If you have a hotpluggable device (e.g. a USB device), then when a disconnect +happens the parent device becomes invalid. Since v4l2_device has a pointer to +that parent device it has to be cleared as well to mark that the parent is +gone. To do this call: + + v4l2_device_disconnect(struct v4l2_device *v4l2_dev); + +This does *not* unregister the subdevs, so you still need to call the +v4l2_device_unregister() function for that. If your driver is not hotpluggable, +then there is no need to call v4l2_device_disconnect(). + Sometimes you need to iterate over all devices registered by a specific driver. This is usually the case if multiple device drivers use the same hardware. E.g. the ivtvfb driver is a framebuffer driver that uses the ivtv |