[PATCH 3.4 102/146] Input: elantech - fix semi-mt protocol for v3 HW

lizf
2015-09-15T09:25:05Z

From: Benjamin Tissoires <benjamin.tissoires@redhat.com>

3.4.109-rc1 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@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
---
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 877dbc8..c907f9d 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -313,7 +313,7 @@ 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);
}

/*
--
1.9.1