Input: MT - make slot assignment work for overcovered solutions

The recent inclusion of a deassignment cost in the slot assignment
algorithm did not properly account for the corner cases where the
solutions are overcovered. This change makes sure the resulting
assignment is unique, allocating new slots when necessary.

Signed-off-by: Henrik Rydberg <rydberg@bitmath.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index cb150a1dbaff9c9e788885747113e83e8f1dbe52..b097af269e0097ae314c9c57c2aca05c4eb5f948 100644 (file)
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -365,27 +365,35 @@ 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;
                        }
+               }
        }
 }