[media] rc: do not wake up rc thread unless there is something to do

The TechnoTrend USB IR Receiver sends 125 ISO URBs per second, even when
there is no IR activity. Reduce the number of wake ups from the other
drivers too.

This saves about 0.25ms/s on a 2.4GHz Core 2 according to powertop.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/rc/ir-raw.c b/drivers/media/rc/ir-raw.c
index a820251..97dc8d1 100644
--- a/drivers/media/rc/ir-raw.c
+++ b/drivers/media/rc/ir-raw.c
@@ -157,7 +157,9 @@
  * This routine (which may be called from an interrupt context) works
  * in similar manner to ir_raw_event_store_edge.
  * This routine is intended for devices with limited internal buffer
- * It automerges samples of same type, and handles timeouts
+ * It automerges samples of same type, and handles timeouts. Returns non-zero
+ * if the event was added, and zero if the event was ignored due to idle
+ * processing.
  */
 int ir_raw_event_store_with_filter(struct rc_dev *dev, struct ir_raw_event *ev)
 {
@@ -184,7 +186,7 @@
 	    dev->raw->this_ev.duration >= dev->timeout)
 		ir_raw_event_set_idle(dev, true);
 
-	return 0;
+	return 1;
 }
 EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter);