Input: MT - add support for balanced slot assignment

Some devices are not fast enough to differentiate between a fast-moving
contact and a new contact. This problem cannot be fully resolved because
information is truly missing, but it is possible to safe-guard against
obvious mistakes by restricting movement with a maximum displacement.

The new problem formulation for dmax > 0 cannot benefit from the speedup
for positive definite matrices, but since the convergence is faster, the
result is about the same. For a handful of contacts, the latency difference
is truly negligible.

Suggested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Henrik Rydberg <rydberg@bitmath.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index f719f28d370c..f205b8be2ce4 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -435,7 +435,7 @@ static void alps_report_mt_data(struct psmouse *psmouse, int n)
         struct alps_fields *f = &priv->f;
         int i, slot[MAX_TOUCHES];
 
-        input_mt_assign_slots(dev, slot, f->mt, n);
+        input_mt_assign_slots(dev, slot, f->mt, n, 0);
         for (i = 0; i < n; i++)
                 alps_set_slot(dev, slot[i], f->mt[i].x, f->mt[i].y);