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

commit d49cb7ae upstream.

commit 421e08c4 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>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

drivers/input/mouse/synaptics.c

@@ -347,15 +347,6 @@ static int synaptics_resolution(struct psmouse *psmouse)
 	unsigned char resp[3];
 	int i;
 
-	for (i = 0; min_max_pnpid_table[i].pnp_ids; i++)
-		if (matches_pnp_id(psmouse, min_max_pnpid_table[i].pnp_ids)) {
-			priv->x_min = min_max_pnpid_table[i].x_min;
-			priv->x_max = min_max_pnpid_table[i].x_max;
-			priv->y_min = min_max_pnpid_table[i].y_min;
-			priv->y_max = min_max_pnpid_table[i].y_max;
-			return 0;
-		}
-
 	if (SYN_ID_MAJOR(priv->identity) < 4)
 		return 0;
 
@@ -366,6 +357,16 @@ static int synaptics_resolution(struct psmouse *psmouse)
 		}
 	}
 
+	for (i = 0; min_max_pnpid_table[i].pnp_ids; i++) {
+		if (matches_pnp_id(psmouse, min_max_pnpid_table[i].pnp_ids)) {
+			priv->x_min = min_max_pnpid_table[i].x_min;
+			priv->x_max = min_max_pnpid_table[i].x_max;
+			priv->y_min = min_max_pnpid_table[i].y_min;
+			priv->y_max = min_max_pnpid_table[i].y_max;
+			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)) {