media: uvcvideo: Fix driver reference counting (f9ffcb0a) · Commits · 戴 / test

kref_init initializes the reference count to 1, not 0. This additional reference is never released since the conversion to reference counters. As a result, uvc_delete is not called anymore when UVC cameras are disconnected. Fix this by adding an additional kref_put in uvc_disconnect and in the probe error path. This also allows to remove the temporary additional reference in uvc_unregister_video. Fixes: ("media: uvcvideo: Convert from using an atomic variable to a reference count") Signed-off-by:

Philipp Zabel <philipp.zabel@gmail.com> Reviewed-by:

Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by:

Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/usb/uvc/uvc_driver.c

+2 −9

Original line number	Diff line number	Diff line
		@@ -1871,13 +1871,6 @@ static void uvc_unregister_video(struct uvc_device *dev)
		{
		struct uvc_streaming *stream;

		/* Unregistering all video devices might result in uvc_delete() being
		* called from inside the loop if there's no open file handle. To avoid
		* that, increment the refcount before iterating over the streams and
		* decrement it when done.
		*/
		kref_get(&dev->ref);

		list_for_each_entry(stream, &dev->streams, list) {
		if (!video_is_registered(&stream->vdev))
		continue;
		@@ -1887,8 +1880,6 @@ static void uvc_unregister_video(struct uvc_device *dev)

		uvc_debugfs_cleanup_stream(stream);
		}

		kref_put(&dev->ref, uvc_delete);
		}

		int uvc_register_video_device(struct uvc_device *dev,
		@@ -2184,6 +2175,7 @@ static int uvc_probe(struct usb_interface *intf,

		error:
		uvc_unregister_video(dev);
		kref_put(&dev->ref, uvc_delete);
		return -ENODEV;
		}

		@@ -2201,6 +2193,7 @@ static void uvc_disconnect(struct usb_interface *intf)
		return;

		uvc_unregister_video(dev);
		kref_put(&dev->ref, uvc_delete);
		}

		static int uvc_suspend(struct usb_interface *intf, pm_message_t message)

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