[PATCH 3.12 078/111] Input: elantech - fix semi-mt protocol for v3 HW

[Jiri Slaby]

From: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit 3c0213d17a09601e0c6c0ae0e27caf70d988290f upstream.

When the v3 hardware sees more than one finger, it uses the semi-mt
protocol to report the touches. However, it currently works when
num_fingers is 0, 1 or 2, but when it is 3 and above, it sends only 1
finger as if num_fingers was 1.

This confuses userspace which knows how to deal with extra fingers
when all the slots are used, but not when some are missing.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=90101

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 drivers/input/mouse/elantech.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index 04a7d9f00928..71540c0eee44 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -314,7 +314,7 @@ static void elantech_report_semi_mt_data(struct input_dev *dev,
 					 unsigned int x2, unsigned int y2)
 {
 	elantech_set_slot(dev, 0, num_fingers != 0, x1, y1);
-	elantech_set_slot(dev, 1, num_fingers == 2, x2, y2);
+	elantech_set_slot(dev, 1, num_fingers >= 2, x2, y2);
 }
 
 /*
-- 
2.4.2

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