From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752921Ab0H1QIx (ORCPT ); Sat, 28 Aug 2010 12:08:53 -0400 Received: from ch-smtp01.sth.basefarm.net ([80.76.149.212]:52973 "EHLO ch-smtp01.sth.basefarm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752737Ab0H1QIv (ORCPT ); Sat, 28 Aug 2010 12:08:51 -0400 Message-ID: <4C79346F.4050409@euromail.se> Date: Sat, 28 Aug 2010 18:08:15 +0200 From: Henrik Rydberg User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.8) Gecko/20100820 Thunderbird/3.1.2 MIME-Version: 1.0 To: =?ISO-8859-1?Q?St=E9phane_Chatty?= CC: Jiri Kosina , Dmitry Torokhov , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] hid: 3m: Correct touchscreen emulation References: <1283005748-3293-1-git-send-email-rydberg@euromail.se> <1283005748-3293-3-git-send-email-rydberg@euromail.se> <2A410207-8AAA-4D5A-846A-B69F007E6800@enac.fr> In-Reply-To: <2A410207-8AAA-4D5A-846A-B69F007E6800@enac.fr> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Originating-IP: 83.248.196.134 X-Scan-Result: No virus found in message 1OpNx2-0007fx-4d. X-Scan-Signature: ch-smtp01.sth.basefarm.net 1OpNx2-0007fx-4d 2913d83f0bc2a983713a8354c0f09b95 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/28/2010 05:56 PM, Stéphane Chatty wrote: > > Le 28 août 10 à 16:29, Henrik Rydberg a écrit : > >> The current code sometimes misses to report the last BTN_TOUCH event >> when multiple fingers are lifted simultaneously. With the >> introduction of MT slots, the tracking id is available to determine >> the oldest active contact. > > Hi Henrik, > > good job on exploiting the sync quirk! > > About the oldest active contact, I'm not so sure though. I don't have the device > with me but I remember that 3M recycle IDs, giving the lowest available ID to > any new finger; this means that the lowest ID is not always the oldest finger. Hi Stéphane, I think we use the term tracking id differently here. The HID_DG_CONTACTID is actually the slot id, and the tracking id is a sequential number, increased whenever the touch is new. I believe the patchset works correctly as long as there is less than 32768 new touches before releasing the oldest one. :-) Cheers, Henrik