From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ping Cheng Subject: Re: [RFC] Multi-Touch (MT) support - arbitration or not Date: Thu, 11 Nov 2010 10:23:55 -0800 Message-ID: References: <20101108035121.GA4630@barra.bne.redhat.com> <4CD7B012.1030809@cena.fr> <20101109033149.GC19313@barra.redhat.com> <20101110044608.GA29110@barra.bne.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-wy0-f174.google.com ([74.125.82.174]:63092 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754614Ab0KKSX6 convert rfc822-to-8bit (ORCPT ); Thu, 11 Nov 2010 13:23:58 -0500 Received: by wyb28 with SMTP id 28so984483wyb.19 for ; Thu, 11 Nov 2010 10:23:56 -0800 (PST) In-Reply-To: Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Chris Bagwell Cc: Peter Hutterer , Benjamin Tissoires , "X.Org Devel List" , Dmitry Torokhov , Daniel Stone , linux-input On Wed, Nov 10, 2010 at 7:57 PM, Chris Bagwell w= rote: > On Tue, Nov 9, 2010 at 10:46 PM, Peter Hutterer > wrote: >> On Mon, Nov 08, 2010 at 10:14:56PM -0600, Chris Bagwell wrote: >>> >>> I've copied #2 below and added my own text in "[]" to be sure and >>> clarify text in context of case #2. >>> >>> 2. =A0 =A0 Report first finger touch as ABS_X/Y events [on touch in= put >>> device] when pen is not in >>> prox. =A0Arbitrating single touch data [on touch input device] when= pen >>> is in prox. Pen data is >>> reported as ABS_X/Y events [on pen input device]. Both ABS_X/Y for = pen >>> or the first finger >>> and ABS_MT_* for MT data are reported [each MT send]. =A0[MT are ev= en >>> sent on touch device even though only 1 in proximity tool possible = so >>> that client can combine both inputs' events and see same behaviour = as >>> if it was a single input device.] >> >> Assuming a split device - why do any filtering at all? >> Report ABS_X/Y for pen on the pen device, touch as MT events on the = touch >> device _and_ first finger touch as ABS_X/Y on the touch device. If u= serspace >> can somehow couple the two devices then it's easy enough to filter t= ouch >> events when necessary. > > Who is audience of these ABS_X/Y events? =A0We are not sending them f= or > MT-aware application benefit. =A0Matter of fact, it slightly complica= tes > MT-aware apps because they have to filter them in addition to > filtering MT events. > > The real audience of ABS_X/Y is either older apps or "simple" apps > (people that chose to keep it simple and not support MT events). =A0T= his > class of apps can't really be expected to bind two devices logically > and mask. =A0So without filtering ABS_X/Y on kernel side, we've > basically made Bamboo drivers unusable with a range of apps; which > probably means xf86-input-{evdev|synaptics} (I can't justify adding > binding logic to those two). I agree with Chris. Filtering touch ABS_X/Y when pen in prox is necessary for non-MT aware apps. It also eases backward support. Ping -- To unsubscribe from this list: send the line "unsubscribe linux-input" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html