[PATCH libinput] touchpad: disable MT for elantech semi-mt touchpads

[Peter Hutterer]

When three fingers are set down on the touchpad, one finger tends to get a 0/0
coordinate, triggering palm detection in the upper left corner. Handle this
like the jumping semi-mt touchpads and disable MT handling and instead
just rely on the x/y axis and the BTN_TOOL_* events.

https://bugs.freedesktop.org/show_bug.cgi?id=93583

This kernel patch is required:
https://lkml.org/lkml/2016/1/11/171

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/evdev-mt-touchpad.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
index 2de2539..f91f839 100644
--- a/src/evdev-mt-touchpad.c
+++ b/src/evdev-mt-touchpad.c
@@ -1496,7 +1496,8 @@ tp_init_slots(struct tp_dispatch *tp,
 	 * explanation.
 	 */
 	if (tp->semi_mt &&
-	    (device->model_flags & EVDEV_MODEL_JUMPING_SEMI_MT)) {
+	    (device->model_flags &
+	     (EVDEV_MODEL_JUMPING_SEMI_MT|EVDEV_MODEL_ELANTECH_TOUCHPAD))) {
 		tp->num_slots = 1;
 		tp->slot = 0;
 		tp->has_mt = false;
-- 
2.5.0