1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
index 4207590b2ac8..a31177390e55 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

diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index 4207590b2ac8..a31177390e55 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt
@@ -105,6 +105,17 @@ You unregister with:
105		105
106	Unregistering will also automatically unregister all subdevs from the device.	106	Unregistering will also automatically unregister all subdevs from the device.
107		107
		108	If you have a hotpluggable device (e.g. a USB device), then when a disconnect
		109	happens the parent device becomes invalid. Since v4l2_device has a pointer to
		110	that parent device it has to be cleared as well to mark that the parent is
		111	gone. To do this call:
		112
		113	v4l2_device_disconnect(struct v4l2_device *v4l2_dev);
		114
		115	This does not unregister the subdevs, so you still need to call the
		116	v4l2_device_unregister() function for that. If your driver is not hotpluggable,
		117	then there is no need to call v4l2_device_disconnect().
		118
108	Sometimes you need to iterate over all devices registered by a specific	119	Sometimes you need to iterate over all devices registered by a specific
109	driver. This is usually the case if multiple device drivers use the same	120	driver. This is usually the case if multiple device drivers use the same
110	hardware. E.g. the ivtvfb driver is a framebuffer driver that uses the ivtv	121	hardware. E.g. the ivtvfb driver is a framebuffer driver that uses the ivtv