From mboxrd@z Thu Jan 1 00:00:00 1970 From: Henrik Rydberg Subject: Re: [PATCH 1/2] HID: multitouch: report MT_TOOL_PALM for non-confident touches Date: Fri, 1 Jun 2018 21:03:21 +0200 Message-ID: <72b7120a-d304-0b2f-d04a-473631623f72@bitmath.org> References: <20170811004500.13740-1-dmitry.torokhov@gmail.com> <20180601184330.GD222005@dtor-ws> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180601184330.GD222005@dtor-ws> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Torokhov , Benjamin Tissoires Cc: Jiri Kosina , Jason Gerecke , Dennis Kempin , Andrew de los Reyes , "open list:HID CORE LAYER" , lkml List-Id: linux-input@vger.kernel.org >> However, I interpret a firmware that send (confidence 1, tip switch 1) >> and then (confidence 0, tip switch 0) a simple release, and the >> confidence bit should not be relayed. > This unfortunately leads to false clicks: you start with finger, so > confidence is 1, then you transition the same touch to palm (use your > thumb and "roll" your hand until heel of it comes into contact with the > screen). The firmware reports "no-confidence" and "release" in the same > report and userspace seeing release does not pay attention to confidence > (i.e. it does exactly "simple release" logic) and this results in UI > interpreting this as a click. With splitting no-confidence > (MT_TOOL_PALM) and release event into separate frames we help userspace > to recognize that the contact should be discarded. This is in part why I objected to this patch on August 11th, 2017. Logically, the confidence state is a property of a contact, not a new type of contact. Trying to use it in any other way is bound to lead to confusion. Henrik