[media] ir-nec-decoder: fix repeat key issue

Fixing the problem with NEC protocol and repeating keys under the following
circumstances. The problem occurs when there is a repeat code without
properly decoded scancode. This leads to repeat the wrong (last decoded)
scancode.

An example from real life:
I am pressing volume down, then several minutes later i am pressing
volume up, but the real scancode is wrongly decoded and only a repeat
event is emitted, so as a result volume is going down while i am holding
volume up button.

The patch fixes above problem using rc_keyup timeout (as pointed by Mauro).
It just prevents key repeats if they appear after rc_keyup.

Signed-off-by: Mariusz Białończyk <manio@skyboo.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/rc/ir-nec-decoder.c

@@ -88,9 +88,13 @@ static int ir_nec_decode(struct rc_dev *dev, struct ir_raw_event ev)
 			data->state = STATE_BIT_PULSE;
 			return 0;
 		} else if (eq_margin(ev.duration, NEC_REPEAT_SPACE, NEC_UNIT / 2)) {
-			rc_repeat(dev);
-			IR_dprintk(1, "Repeat last key\n");
-			data->state = STATE_TRAILER_PULSE;
+			if (!dev->keypressed) {
+				IR_dprintk(1, "Discarding last key repeat: event after key up\n");
+			} else {
+				rc_repeat(dev);
+				IR_dprintk(1, "Repeat last key\n");
+				data->state = STATE_TRAILER_PULSE;
+			}
 			return 0;
 		}