Input: elantech - fix detection of touchpad on ASUS s301l

Adjust Elantech signature validation to account fo rnewer models of
touchpads.

Cc: stable@vger.kernel.org
Reported-and-tested-by: Màrius Monton <marius.monton@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index da51738eb59e..d71bd3635de1 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -1331,6 +1331,13 @@ static bool elantech_is_signature_valid(const unsigned char *param)
         if (param[1] == 0)
                 return true;
 
+        /*
+         * Some models have a revision higher then 20. Meaning param[2] may
+         * be 10 or 20, skip the rates check for these.
+         */
+        if (param[0] == 0x46 && (param[1] & 0xef) == 0x0f && param[2] < 40)
+                return true;
+
         for (i = 0; i < ARRAY_SIZE(rates); i++)
                 if (param[2] == rates[i])
                         return false;