Input: elants_i2c - fix division by zero if firmware reports zero phys size

Touchscreen firmware of ASUS Transformer TF700T reports zeros for the phys
size. Hence check whether the size is zero and don't set the resolution in
this case.

Reported-by: Jasper Korten <jja2000@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20210302100824.3423-1-digetx@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
index 4c2b579f6c8bf35a07a22ca0d95db620defff79a..78172c31529a4e4b9d0bd949fb31603e7334c301 100644 (file)
--- a/drivers/input/touchscreen/elants_i2c.c
+++ b/drivers/input/touchscreen/elants_i2c.c
@@ -1441,7 +1441,7 @@ static int elants_i2c_probe(struct i2c_client *client,
 
        touchscreen_parse_properties(ts->input, true, &ts->prop);
 
-       if (ts->chip_id == EKTF3624) {
+       if (ts->chip_id == EKTF3624 && ts->phy_x && ts->phy_y) {
                /* calculate resolution from size */
                ts->x_res = DIV_ROUND_CLOSEST(ts->prop.max_x, ts->phy_x);
                ts->y_res = DIV_ROUND_CLOSEST(ts->prop.max_y, ts->phy_y);