1 files changed, 24 insertions, 11 deletions

diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index cb150a1dbaff..54fce56c8023 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -88,10 +88,13 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
 			goto err_mem;
 	}
 
-	/* Mark slots as 'unused' */
+	/* Mark slots as 'inactive' */
 	for (i = 0; i < num_slots; i++)
 		input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1);
 
+	/* Mark slots as 'unused' */
+	mt->frame = 1;
+
 	dev->mt = mt;
 	return 0;
 err_mem:
@@ -365,27 +368,35 @@ static void input_mt_set_slots(struct input_mt *mt,
 			       int *slots, int num_pos)
 {
 	struct input_mt_slot *s;
-	int *w = mt->red, *p;
+	int *w = mt->red, j;
 
-	for (p = slots; p != slots + num_pos; p++)
-		*p = -1;
+	for (j = 0; j != num_pos; j++)
+		slots[j] = -1;
 
 	for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
 		if (!input_mt_is_active(s))
 			continue;
-		for (p = slots; p != slots + num_pos; p++)
-			if (*w++ < 0)
-				*p = s - mt->slots;
+
+		for (j = 0; j != num_pos; j++) {
+			if (w[j] < 0) {
+				slots[j] = s - mt->slots;
+				break;
+			}
+		}
+
+		w += num_pos;
 	}
 
 	for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
 		if (input_mt_is_active(s))
 			continue;
-		for (p = slots; p != slots + num_pos; p++)
-			if (*p < 0) {
-				*p = s - mt->slots;
+
+		for (j = 0; j != num_pos; j++) {
+			if (slots[j] < 0) {
+				slots[j] = s - mt->slots;
 				break;
 			}
+		}
 	}
 }
 
@@ -439,6 +450,8 @@ EXPORT_SYMBOL(input_mt_assign_slots);
  * set the key on the first unused slot and return.
  *
  * If no available slot can be found, -1 is returned.
+ * Note that for this function to work properly, input_mt_sync_frame() has
+ * to be called at each frame.
  */
 int input_mt_get_slot_by_key(struct input_dev *dev, int key)
 {
@@ -453,7 +466,7 @@ int input_mt_get_slot_by_key(struct input_dev *dev, int key)
 			return s - mt->slots;
 
 	for (s = mt->slots; s != mt->slots + mt->num_slots; s++)
-		if (!input_mt_is_active(s)) {
+		if (!input_mt_is_active(s) && !input_mt_is_used(mt, s)) {
 			s->key = key;
 			return s - mt->slots;
 		}