Input: alps - improve 2-finger reporting on v3 models

V3 models only report mt bitmap data when there are 2 or more fingers on
the touchpad. So always generate 2 positions in alps_process_bitmap, and
for v3 models only fall back to st data when there was no mt data in a
mt packet (which should never happen).

This fixes 2 finger scrolling not working when using 2 fingers close to
each other.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index e15daea568644e0a08eca3beefe49552bdd7b984..cc197d7473c9f4d1a48253617e728fa892069e37 100644 (file)
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -407,23 +407,20 @@ static int alps_process_bitmap(struct alps_data *priv,
        fingers = max(fingers_x, fingers_y);
 
        /*
-        * If total fingers is > 1 but either axis reports only a single
-        * contact, we have overlapping or adjacent fingers. For the
-        * purposes of creating a bounding box, divide the single contact
-        * (roughly) equally between the two points.
+        * If an axis reports only a single contact, we have overlapping or
+        * adjacent fingers. Divide the single contact between the two points.
         */
-       if (fingers > 1) {
-               if (fingers_x == 1) {
-                       i = x_low.num_bits / 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);
-               } else if (fingers_y == 1) {
-                       i = y_low.num_bits / 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);
-               }
+       if (fingers_x == 1) {
+               i = x_low.num_bits / 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;
+               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);
        }
 
        *x1 = (priv->x_max * (2 * x_low.start_bit + x_low.num_bits - 1)) /
@@ -431,14 +428,12 @@ static int alps_process_bitmap(struct alps_data *priv,
        *y1 = (priv->y_max * (2 * y_low.start_bit + y_low.num_bits - 1)) /
              (2 * (priv->y_bits - 1));
 
-       if (fingers > 1) {
-               *x2 = (priv->x_max *
-                      (2 * x_high.start_bit + x_high.num_bits - 1)) /
-                     (2 * (priv->x_bits - 1));
-               *y2 = (priv->y_max *
-                      (2 * y_high.start_bit + y_high.num_bits - 1)) /
-                     (2 * (priv->y_bits - 1));
-       }
+       *x2 = (priv->x_max *
+              (2 * x_high.start_bit + x_high.num_bits - 1)) /
+             (2 * (priv->x_bits - 1));
+       *y2 = (priv->y_max *
+              (2 * y_high.start_bit + y_high.num_bits - 1)) /
+             (2 * (priv->y_bits - 1));
 
        return fingers;
 }
@@ -607,8 +602,7 @@ static void alps_process_touchpad_packet_v3_v5(struct psmouse *psmouse)
        unsigned char *packet = psmouse->packet;
        struct input_dev *dev = psmouse->dev;
        struct input_dev *dev2 = priv->dev2;
-       int x1 = 0, y1 = 0, x2 = 0, y2 = 0;
-       int fingers = 0, bmap_fn;
+       int x1 = 0, y1 = 0, x2 = 0, y2 = 0, fingers = 0;
        struct alps_fields f = {0};
 
        priv->decode_fields(&f, packet, psmouse);
@@ -629,16 +623,10 @@ static void alps_process_touchpad_packet_v3_v5(struct psmouse *psmouse)
                if (f.is_mp) {
                        fingers = f.fingers;
                        if (priv->proto_version == ALPS_PROTO_V3) {
-                               bmap_fn = alps_process_bitmap(priv, f.x_map,
-                                                             f.y_map, &x1, &y1,
-                                                             &x2, &y2);
-
-                               /*
-                                * We shouldn't report more than one finger if
-                                * we don't have two coordinates.
-                                */
-                               if (fingers > 1 && bmap_fn < 2)
-                                       fingers = bmap_fn;
+                               if (alps_process_bitmap(priv, f.x_map,
+                                                       f.y_map, &x1, &y1,
+                                                       &x2, &y2) == 0)
+                                       fingers = 0; /* Use st data */
 
                                /* Now process position packet */
                                priv->decode_fields(&f, priv->multi_data,