Input: synaptics - fix resolution for manually provided min/max

commit d49cb7aeebb974713f9f7ab2991352d3050b095b upstream.

commit 421e08c41fda fixed the reported min/max for the X and Y axis,
but unfortunately, it broke the resolution of those same axis.

On the t540p, the resolution is the same regarding X and Y. It is not
a problem for xf86-input-synaptics because this driver is only interested
in the ratio between X and Y.
Unfortunately, xf86-input-cmt uses directly the resolution, and having a
null resolution leads to some divide by 0 errors, which are translated by
-infinity in the resulting coordinates.

Reported-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
[bwh: Backported to 3.2: I didn't apply the PNP ID changes, so the
 code being moved looks different]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
index d2ce1b4..df8b72b 100644 (file)
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c
@@ -245,14 +245,6 @@ static int synaptics_resolution(struct psmouse *psmouse)
        struct synaptics_data *priv = psmouse->private;
        unsigned char resp[3];
 
-       if (quirk_min_max) {
-               priv->x_min = quirk_min_max[0];
-               priv->x_max = quirk_min_max[1];
-               priv->y_min = quirk_min_max[2];
-               priv->y_max = quirk_min_max[3];
-               return 0;
-       }
-
        if (SYN_ID_MAJOR(priv->identity) < 4)
                return 0;
 
@@ -263,6 +255,14 @@ static int synaptics_resolution(struct psmouse *psmouse)
                }
        }
 
+       if (quirk_min_max) {
+               priv->x_min = quirk_min_max[0];
+               priv->x_max = quirk_min_max[1];
+               priv->y_min = quirk_min_max[2];
+               priv->y_max = quirk_min_max[3];
+               return 0;
+       }
+
        if (SYN_EXT_CAP_REQUESTS(priv->capabilities) >= 5 &&
            SYN_CAP_MAX_DIMENSIONS(priv->ext_cap_0c)) {
                if (synaptics_send_cmd(psmouse, SYN_QUE_EXT_MAX_COORDS, resp)) {