We assumed all touch interfaces report touch data. But, Bamboo and Intuos non-touch devices report express keys on touch interface. We need to check touch_max before counting touches. Reported-by: Tasos Sahanidis <tasos@xxxxxxxxxxxx> Signed-off-by: Ping Cheng <pingc@xxxxxxxxx> --- Hi Jiri, this patch is based on for-4.1/wacom. The issue was initially introduced in 4.1. --- drivers/hid/wacom_wac.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c index 69c7df7..1cd80d2 100644 --- a/drivers/hid/wacom_wac.c +++ b/drivers/hid/wacom_wac.c @@ -1072,6 +1072,9 @@ static int wacom_wac_finger_count_touches(struct wacom_wac *wacom) int count = 0; int i; + if (!touch_max) + return 0; + /* non-HID_GENERIC single touch input doesn't call this routine */ if ((touch_max == 1) && (wacom->features.type == HID_GENERIC)) return wacom->hid_data.tipswitch && -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html