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>
diff --git a/include/linux/input/mt.h b/include/linux/input/mt.h
index f583ff6..d7188de 100644
--- a/include/linux/input/mt.h
+++ b/include/linux/input/mt.h
@@ -119,7 +119,8 @@
};
int input_mt_assign_slots(struct input_dev *dev, int *slots,
- const struct input_mt_pos *pos, int num_pos);
+ const struct input_mt_pos *pos, int num_pos,
+ int dmax);
int input_mt_get_slot_by_key(struct input_dev *dev, int key);