[PATCH 1/2] Input - elantech: fix semi-mt protocol for v3 HW

From: Benjamin Tissoires
Date: Wed Apr 22 2015 - 11:45:20 EST


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

CC: stable@xxxxxxxxxxxxxxx

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
---
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 991dc6b..79363b6 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -315,7 +315,7 @@ 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);
}

/*
--
2.1.0

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