Input: alps - fix a mismatch between a condition check and its comment

In the function alps_is_cs19_trackpoint(), we check if the param[1] is
in the 0x20~0x2f range, but the code we wrote for this checking is not
correct:
(param[1] & 0x20) does not mean param[1] is in the range of 0x20~0x2f,
it also means the param[1] is in the range of 0x30~0x3f, 0x60~0x6f...

Now fix it with a new condition checking ((param[1] & 0xf0) == 0x20).

Fixes: 7e4935ccc323 ("Input: alps - don't handle ALPS cs19 trackpoint-only device")
Cc: stable@vger.kernel.org
Signed-off-by: Hui Wang <hui.wang@canonical.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 62ffea00902a6b2257ddbd79fb65f1bed4d581e6..34700eda04290402b1280a619e7917b1bbece407 100644 (file)
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -2876,7 +2876,7 @@ static bool alps_is_cs19_trackpoint(struct psmouse *psmouse)
         * trackpoint-only devices have their variant_ids equal
         * TP_VARIANT_ALPS and their firmware_ids are in 0x20~0x2f range.
         */
-       return param[0] == TP_VARIANT_ALPS && (param[1] & 0x20);
+       return param[0] == TP_VARIANT_ALPS && ((param[1] & 0xf0) == 0x20);
 }
 
 static int alps_identify(struct psmouse *psmouse, struct alps_data *priv)