From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1754512AbcEPRxr (ORCPT <rfc822;w@1wt.eu>);
	Mon, 16 May 2016 13:53:47 -0400
Received: from mail-pa0-f68.google.com ([209.85.220.68]:34279 "EHLO
	mail-pa0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1754398AbcEPRxp (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Mon, 16 May 2016 13:53:45 -0400
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
X-Google-Original-From: Dmitry Torokhov <Dmitry.torokhov@gmail.com>
Date: Mon, 16 May 2016 10:53:42 -0700
To: =?utf-8?B?5buW5bSH5qau?= <kt.liao@emc.com.tw>
Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
        zac.hsieh@emc.com.tw,
        =?utf-8?B?6buD5LiW6bWsIOe2k+eQhg==?= <phoenix@emc.com.tw>,
        "'Charles Mooney'" <charliemooney@google.com>,
        "'Agnes Cheng'" <agnescheng@google.com>
Subject: Re: [PATCH] Input: Change BTN_TOOL_FINGER flag when hover event
 trigger
Message-ID: <20160516175342.GD12752@dtor-ws>
References: <C2DEC699-8A1A-484D-83F2-637F5EF94C7B@emc.com.tw>
 <006901d1acea$8207d090$861771b0$@emc.com.tw>
 <00be01d1af65$ec37c290$c4a747b0$@emc.com.tw>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <00be01d1af65$ec37c290$c4a747b0$@emc.com.tw>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi Kt,

On Mon, May 16, 2016 at 07:27:25PM +0800, 廖崇榮 wrote:
> 
> Only ABS_DISTANCE is not enough for upper OS to distingiush hover event be
> triggered from object from faraway to and close touchpad surface or from
> object prepare to leave the touchpad surface. Add BTN_TOOL_FINGER flag to
> help it.
> 
>                  object_from_faraway    object_inside_hover_area
> object_touch_surface
> BTN_TOUCH                 0                          0             1
> BTN_TOOL_FINGER           0                          1              1
> ABS_DISTANCE               0                           1             0
> 
> Signed-off by: Duson Lin <dusonlin@emc.com.tw>

I was wondering if we could do without modifying all the drivers that
are using input_mt_report_pointer_emulation(), by figuring out if we
should be emitting BTN_TOOL_FINGER right there:

"If device supports ABS_DISTANCE and does not support ABS_MT_DISTANCE and
ABS_DISTANCE != 0 is reported in current frame and there are no other
contacts then report BTN_TOOL_FINGER."

Thanks.

-- 
Dmitry