From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:54858 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965099AbcA0TGl (ORCPT ); Wed, 27 Jan 2016 14:06:41 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jason Gerecke , Jiri Kosina Subject: [PATCH 4.3 149/157] HID: wacom: Expect touch_max touches if HID_DG_CONTACTCOUNT not present Date: Wed, 27 Jan 2016 10:13:36 -0800 Message-Id: <20160127180940.567265169@linuxfoundation.org> In-Reply-To: <20160127180932.533735338@linuxfoundation.org> References: <20160127180932.533735338@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: stable-owner@vger.kernel.org List-ID: 4.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Gerecke commit df7079380554e6e8e13a0812c7e6c72f669aba5c upstream. When introduced in commit 1b5d514, the check 'if (hid_data->cc_index >= 0)' in 'wacom_wac_finger_pre_report' was intended to switch where the driver got the expected number of contacts from: HID_DG_CONTACTCOUNT if the usage was present, or 'touch_max' otherwise. Unfortunately, an oversight worthy of a brown paper bag (specifically, that 'cc_index' could never be negative) meant that the latter 'else' clause would never be entered. The patch prior to this one introduced a way for 'cc_index' to be negative, but only if HID_DG_CONTACTCOUNT is present in some report _other_ than the one being processed. To ensure the 'else' clause is also entered for devices which don't have HID_DG_CONTACTCOUNT on _any_ report, we add the additional constraint that 'cc_report' be non-zero (which is true only if the usage is present in some report). Signed-off-by: Jason Gerecke Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/wacom_wac.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/hid/wacom_wac.c +++ b/drivers/hid/wacom_wac.c @@ -1740,8 +1740,8 @@ static void wacom_wac_finger_pre_report( } } } - - if (hid_data->cc_index >= 0) { + if (hid_data->cc_report != 0 && + hid_data->cc_index >= 0) { struct hid_field *field = report->field[hid_data->cc_index]; int value = field->value[hid_data->cc_value_index]; if (value)