From mboxrd@z Thu Jan 1 00:00:00 1970 From: Derek Foreman Subject: Re: [PATCH 4/4] Input: Synaptics: Add INPUT_PROP_SYNAPTICS_T3R2 property Date: Mon, 13 Jun 2011 10:36:54 -0400 Message-ID: <4DF62086.3040800@collabora.co.uk> References: <1307735704-30673-1-git-send-email-derek.foreman@collabora.co.uk> <1307735704-30673-5-git-send-email-derek.foreman@collabora.co.uk> <20110610211353.GD5925@polaris.bitmath.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from bhuna.collabora.co.uk ([93.93.128.226]:57353 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753125Ab1FMOhF (ORCPT ); Mon, 13 Jun 2011 10:37:05 -0400 In-Reply-To: <20110610211353.GD5925@polaris.bitmath.org> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Henrik Rydberg Cc: Derek Foreman , linux-input@vger.kernel.org On 06/10/11 17:13, Henrik Rydberg wrote: > On Fri, Jun 10, 2011 at 03:55:04PM -0400, Derek Foreman wrote: >> This new property indicates that the trackpad is able to track more than two contacts, but can only report the positions of two contacts due to bus bandwidth limitations. >> >> Signed-off-by: Derek Foreman >> --- >> drivers/input/mouse/synaptics.c | 3 +++ >> include/linux/input.h | 1 + >> 2 files changed, 4 insertions(+), 0 deletions(-) > > This information is already contained in INPUT_PROP_SEMI_MT, together > with the use of BTN_TRIPLETAP. Please check > Documentation/input/event-codes.txt for further details. I really sorry, but I don't understand how this provides the same information. INPUT_PROP_SEMI_MT, at least according to input.h specifies that the device reports a rectangle only, and not accurate touch co-ordinates. BTN_TOOL_TRIPLETAP indicates that there are 3 fingers on the pad. My intent was to indicate to userspace that the device is reporting co-ordinates like certain synaptics devices do: 3 fingers are accurately tracked 2 fingers are accurately (not bounding box) reported Further, all the idiosyncrasies of the synaptics method of reporting apply: The device has 3 "slots" for tracking data, and once they are all filled, it reports slots 1 and 3. If the slot 1 contact is lifted, slots 2 and 3 will report. If a third finger is once again added to the pad, it will become the new slot 1. INPUT_PROP_SEMI_MT is actually inaccurate for these devices, and in retrospect, the bounding box patch should have removed that bit from the properties of the devices it applies to.