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path: root/drivers/media/video/v4l2-ctrls.c
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Diffstat (limited to 'drivers/media/video/v4l2-ctrls.c')
-rw-r--r--drivers/media/video/v4l2-ctrls.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c
index 5f316667c142..d084cea2b3ba 100644
--- a/drivers/media/video/v4l2-ctrls.c
+++ b/drivers/media/video/v4l2-ctrls.c
@@ -1013,6 +1013,7 @@ static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
insertion is an O(1) operation. */
if (list_empty(&hdl->ctrl_refs) || id > node2id(hdl->ctrl_refs.prev)) {
list_add_tail(&new_ref->node, &hdl->ctrl_refs);
+ hdl->nr_of_refs++;
goto insert_in_hash;
}
@@ -2061,3 +2062,22 @@ void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct v4l2_fh *fh)
v4l2_ctrl_unlock(ctrl);
}
EXPORT_SYMBOL(v4l2_ctrl_del_fh);
+
+int v4l2_ctrl_subscribe_fh(struct v4l2_fh *fh,
+ struct v4l2_event_subscription *sub, unsigned n)
+{
+ struct v4l2_ctrl_handler *hdl = fh->ctrl_handler;
+ int ret = 0;
+
+ if (!fh->events)
+ ret = v4l2_event_init(fh);
+ if (!ret) {
+ if (hdl->nr_of_refs * 2 > n)
+ n = hdl->nr_of_refs * 2;
+ ret = v4l2_event_alloc(fh, n);
+ }
+ if (!ret)
+ ret = v4l2_event_subscribe(fh, sub);
+ return ret;
+}
+EXPORT_SYMBOL(v4l2_ctrl_subscribe_fh);