Input: make events() method return number of events processed

In preparation to consolidating filtering and event processing in the
input core change events() method to return number of events processed
by it.

Reviewed-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240703213756.3375978-4-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/evdev.c

@@ -288,8 +288,8 @@ static void evdev_pass_values(struct evdev_client *client,
 /*
  * Pass incoming events to all connected clients.
  */
-static void evdev_events(struct input_handle *handle,
-			 const struct input_value *vals, unsigned int count)
+static unsigned int evdev_events(struct input_handle *handle,
+				 struct input_value *vals, unsigned int count)
 {
 	struct evdev *evdev = handle->private;
 	struct evdev_client *client;
@@ -306,6 +306,8 @@ static void evdev_events(struct input_handle *handle,
 			evdev_pass_values(client, vals, count, ev_time);
 
 	rcu_read_unlock();
+
+	return count;
 }
 
 static int evdev_fasync(int fd, struct file *file, int on)

include/linux/input.h

@@ -275,7 +275,8 @@ struct input_handle;
  *	it may not sleep
  * @events: event sequence handler. This method is being called by
  *	input core with interrupts disabled and dev->event_lock
- *	spinlock held and so it may not sleep
+ *	spinlock held and so it may not sleep. The method must return
+ *	number of events passed to it.
  * @filter: similar to @event; separates normal event handlers from
  *	"filters".
  * @match: called after comparing device's id with handler's id_table
@@ -312,8 +313,8 @@ struct input_handler {
 	void *private;
 
 	void (*event)(struct input_handle *handle, unsigned int type, unsigned int code, int value);
-	void (*events)(struct input_handle *handle,
-		       const struct input_value *vals, unsigned int count);
+	unsigned int (*events)(struct input_handle *handle,
+			       struct input_value *vals, unsigned int count);
 	bool (*filter)(struct input_handle *handle, unsigned int type, unsigned int code, int value);
 	bool (*match)(struct input_handler *handler, struct input_dev *dev);
 	int (*connect)(struct input_handler *handler, struct input_dev *dev, const struct input_device_id *id);