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UPSTREAM: media: uvcvideo: Fix driver reference counting

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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.

Change-Id: Ief203c8e090b57174ab76e9b0a8f88b7afd17cbb
Fixes: 9d15cd958c ("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>
Signed-off-by: William Wu <william.wu@rock-chips.com>
(cherry picked from commit f9ffcb0a21)
This commit is contained in:
Philipp Zabel
2018-05-21 06:24:58 -04:00
committed by Tao Huang
parent 64d870b993
commit 72b334d84d
1 changed files with 2 additions and 9 deletions
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11
drivers/media/usb/uvc/uvc_driver.c
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@@ -1844,13 +1844,6 @@ 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;
@@ -1860,8 +1853,6 @@ 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,
@@ -2138,6 +2129,7 @@ static int uvc_probe(struct usb_interface *intf,
error:
uvc_unregister_video(dev);
kref_put(&dev->ref, uvc_delete);
return -ENODEV;
}
@@ -2155,6 +2147,7 @@ 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)