[media] v4l2-ctrls: Use v4l2_subscribed_event_ops

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[hans.verkuil@cisco.com: Fix a locking bug]
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/ivtv/ivtv-ioctl.c

@@ -1468,8 +1468,9 @@ static int ivtv_subscribe_event(struct v4l2_fh *fh, struct v4l2_event_subscripti
 	switch (sub->type) {
 	case V4L2_EVENT_VSYNC:
 	case V4L2_EVENT_EOS:
-	case V4L2_EVENT_CTRL:
 		return v4l2_event_subscribe(fh, sub, 0, NULL);
+	case V4L2_EVENT_CTRL:
+		return v4l2_event_subscribe(fh, sub, 0, &v4l2_ctrl_sub_ev_ops);
 	default:
 		return -EINVAL;
 	}

drivers/media/video/v4l2-ctrls.c

@@ -2424,9 +2424,13 @@ int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
 }
 EXPORT_SYMBOL(v4l2_ctrl_s_ctrl);
 
-void v4l2_ctrl_add_event(struct v4l2_ctrl *ctrl,
-				struct v4l2_subscribed_event *sev)
+static int v4l2_ctrl_add_event(struct v4l2_subscribed_event *sev)
 {
+	struct v4l2_ctrl *ctrl = v4l2_ctrl_find(sev->fh->ctrl_handler, sev->id);
+
+	if (ctrl == NULL)
+		return -EINVAL;
+
 	v4l2_ctrl_lock(ctrl);
 	list_add_tail(&sev->node, &ctrl->ev_subs);
 	if (ctrl->type != V4L2_CTRL_TYPE_CTRL_CLASS &&
@@ -2440,17 +2444,40 @@ void v4l2_ctrl_add_event(struct v4l2_ctrl *ctrl,
 		v4l2_event_queue_fh(sev->fh, &ev);
 	}
 	v4l2_ctrl_unlock(ctrl);
+	return 0;
 }
-EXPORT_SYMBOL(v4l2_ctrl_add_event);
 
-void v4l2_ctrl_del_event(struct v4l2_ctrl *ctrl,
-				struct v4l2_subscribed_event *sev)
+static void v4l2_ctrl_del_event(struct v4l2_subscribed_event *sev)
 {
+	struct v4l2_ctrl *ctrl = v4l2_ctrl_find(sev->fh->ctrl_handler, sev->id);
+
 	v4l2_ctrl_lock(ctrl);
 	list_del(&sev->node);
 	v4l2_ctrl_unlock(ctrl);
 }
-EXPORT_SYMBOL(v4l2_ctrl_del_event);
+
+void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new)
+{
+	u32 old_changes = old->u.ctrl.changes;
+
+	old->u.ctrl = new->u.ctrl;
+	old->u.ctrl.changes |= old_changes;
+}
+EXPORT_SYMBOL(v4l2_ctrl_replace);
+
+void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new)
+{
+	new->u.ctrl.changes |= old->u.ctrl.changes;
+}
+EXPORT_SYMBOL(v4l2_ctrl_merge);
+
+const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops = {
+	.add = v4l2_ctrl_add_event,
+	.del = v4l2_ctrl_del_event,
+	.replace = v4l2_ctrl_replace,
+	.merge = v4l2_ctrl_merge,
+};
+EXPORT_SYMBOL(v4l2_ctrl_sub_ev_ops);
 
 int v4l2_ctrl_log_status(struct file *file, void *fh)
 {
@@ -2468,7 +2495,7 @@ int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
 				struct v4l2_event_subscription *sub)
 {
 	if (sub->type == V4L2_EVENT_CTRL)
-		return v4l2_event_subscribe(fh, sub, 0, NULL);
+		return v4l2_event_subscribe(fh, sub, 0, &v4l2_ctrl_sub_ev_ops);
 	return -EINVAL;
 }
 EXPORT_SYMBOL(v4l2_ctrl_subscribe_event);

drivers/media/video/v4l2-event.c

@@ -25,7 +25,6 @@
 #include <media/v4l2-dev.h>
 #include <media/v4l2-fh.h>
 #include <media/v4l2-event.h>
-#include <media/v4l2-ctrls.h>
 
 #include <linux/sched.h>
 #include <linux/slab.h>
@@ -203,30 +202,11 @@ int v4l2_event_pending(struct v4l2_fh *fh)
 }
 EXPORT_SYMBOL_GPL(v4l2_event_pending);
 
-static void ctrls_replace(struct v4l2_event *old, const struct v4l2_event *new)
-{
-	u32 old_changes = old->u.ctrl.changes;
-
-	old->u.ctrl = new->u.ctrl;
-	old->u.ctrl.changes |= old_changes;
-}
-
-static void ctrls_merge(const struct v4l2_event *old, struct v4l2_event *new)
-{
-	new->u.ctrl.changes |= old->u.ctrl.changes;
-}
-
-static const struct v4l2_subscribed_event_ops ctrl_ops = {
-	.replace = ctrls_replace,
-	.merge = ctrls_merge,
-};
-
 int v4l2_event_subscribe(struct v4l2_fh *fh,
 			 struct v4l2_event_subscription *sub, unsigned elems,
 			 const struct v4l2_subscribed_event_ops *ops)
 {
 	struct v4l2_subscribed_event *sev, *found_ev;
-	struct v4l2_ctrl *ctrl = NULL;
 	unsigned long flags;
 	unsigned i;
 
@@ -235,11 +215,6 @@ int v4l2_event_subscribe(struct v4l2_fh *fh,
 
 	if (elems < 1)
 		elems = 1;
-	if (sub->type == V4L2_EVENT_CTRL) {
-		ctrl = v4l2_ctrl_find(fh->ctrl_handler, sub->id);
-		if (ctrl == NULL)
-			return -EINVAL;
-	}
 
 	sev = kzalloc(sizeof(*sev) + sizeof(struct v4l2_kevent) * elems, GFP_KERNEL);
 	if (!sev)
@@ -251,9 +226,6 @@ int v4l2_event_subscribe(struct v4l2_fh *fh,
 	sev->flags = sub->flags;
 	sev->fh = fh;
 	sev->ops = ops;
-	if (ctrl) {
-		sev->ops = &ctrl_ops;
-	}
 
 	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
 	found_ev = v4l2_event_subscribed(fh, sub->type, sub->id);
@@ -275,10 +247,6 @@ int v4l2_event_subscribe(struct v4l2_fh *fh,
 		}
 	}
 
-	/* v4l2_ctrl_add_event uses a mutex, so do this outside the spin lock */
-	if (ctrl)
-		v4l2_ctrl_add_event(ctrl, sev);
-
 	/* Mark as ready for use */
 	sev->elems = elems;
 
@@ -338,13 +306,6 @@ int v4l2_event_unsubscribe(struct v4l2_fh *fh,
 	if (sev && sev->ops && sev->ops->del)
 		sev->ops->del(sev);
 
-	if (sev && sev->type == V4L2_EVENT_CTRL) {
-		struct v4l2_ctrl *ctrl = v4l2_ctrl_find(fh->ctrl_handler, sev->id);
-
-		if (ctrl)
-			v4l2_ctrl_del_event(ctrl, sev);
-	}
-
 	kfree(sev);
 
 	return 0;

include/media/v4l2-ctrls.h

@@ -491,10 +491,9 @@ s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
 int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
 
 /* Internal helper functions that deal with control events. */
-void v4l2_ctrl_add_event(struct v4l2_ctrl *ctrl,
-		struct v4l2_subscribed_event *sev);
-void v4l2_ctrl_del_event(struct v4l2_ctrl *ctrl,
-		struct v4l2_subscribed_event *sev);
+extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
+void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
+void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
 
 struct file;
 /* Can be used as a vidioc_log_status function that just dumps all controls