1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index fbe29fcb15c5..f4b58f77c524 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:
@@ -430,6 +433,8 @@ 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)
 {
@@ -444,7 +449,7 @@ 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;
                 }