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[06/14] alps: process_bitmap: Round down when spreading adjescent fingers over 2 points

Message ID 1404919459-23561-7-git-send-email-hdegoede@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Hans de Goede July 9, 2014, 3:24 p.m. UTC 
This fixes 2 fingers at the same height or width on the touchpad getting
reported at different y / x coordinates.

Note num_bits is always at least 1.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/input/mouse/alps.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
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Patch

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index ebf8187..f8c04fc 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -391,13 +391,13 @@  static int alps_process_bitmap(struct alps_data *priv,
 	 * adjacent fingers. Divide the single contact between the two points.
 	 */
 	if (fingers_x == 1) {
-		i = x_low.num_bits / 2;
+		i = (x_low.num_bits - 1) / 2;
 		x_low.num_bits = x_low.num_bits - i;
 		x_high.start_bit = x_low.start_bit + i;
 		x_high.num_bits = max(i, 1);
 	}
 	if (fingers_y == 1) {
-		i = y_low.num_bits / 2;
+		i = (y_low.num_bits - 1) / 2;
 		y_low.num_bits = y_low.num_bits - i;
 		y_high.start_bit = y_low.start_bit + i;
 		y_high.num_bits = max(i, 1);