From mboxrd@z Thu Jan 1 00:00:00 1970 From: Henrik Rydberg Subject: Re: [PATCH 7/7] elantech: average the two coordinates when 2 fingers Date: Mon, 02 Aug 2010 19:15:23 +0200 Message-ID: <4C56FD2B.8040703@euromail.se> References: <4C567F27.7070900@tudelft.nl> <4C5697C4.1020801@euromail.se> <4C56A81E.3040703@tudelft.nl> <4C56AA67.8000902@euromail.se> <4C56AD12.1080106@tudelft.nl> <4C56B00B.50204@euromail.se> <4C56B686.60606@tudelft.nl> <4C56BA13.3030104@euromail.se> <4C56BE30.2070807@tudelft.nl> <4C56C213.2010605@euromail.se> <20100802163913.GB3276@core.coreip.homeip.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from ch-smtp01.sth.basefarm.net ([80.76.149.212]:52734 "EHLO ch-smtp01.sth.basefarm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751330Ab0HBRP1 (ORCPT ); Mon, 2 Aug 2010 13:15:27 -0400 In-Reply-To: <20100802163913.GB3276@core.coreip.homeip.net> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Dmitry Torokhov Cc: =?ISO-8859-1?Q?=C9ric_Piel?= , Chris Bagwell , "linux-input@vger.kernel.org" , Florian Ragwitz On 08/02/2010 06:39 PM, Dmitry Torokhov wrote: > On Mon, Aug 02, 2010 at 03:03:15PM +0200, Henrik Rydberg wrote: >> On 08/02/2010 02:46 PM, =C9ric Piel wrote: >> >> [...] >> >>>> >>>> We can do better in the sense that since the device cannot comply = with MT-A, we >>>> can do as close as possible to MT-B with less cpu usage. But frank= ly, the best >>>> solution at this stage seems to be to drop MT handling altogether,= since there >>>> does not seem to be any plan to use it. >>> Ah, this alternative solution is a bit boring ;-) In addition it's = not >>> compatible with my own master plan to eventually have the "pinch to >>> zoom" and "rotate to rotate" gestures work on my laptop, like in Wi= ndows ;-) >> >> >> Since rotational symmetry is what prevents us from implementing prop= er MT >> support, it is not likely going to work anyways. >> >=20 > Not work at all or not work as good as with other devices? "Not as go= od" > is still OK, hardware is different and we have to make the best of it= =2E > The same elantech does not export pressure (at lest the version in > mainline does not) and thus users are unable to adjust sensitivity. > Still the device is useable with Synaptics X. This whole thread started off as a question how the ABS_X/Y should be r= eported in the presence of two fingers. Given that the elantech driver can repo= rt _some_ point via ABS_X/Y, and the number of fingers, the device should be usab= le with Synaptics X. If there is a problem with a jumping cursor, I have a feel= ing this is a bug that should be fixed in Synaptics X. As far as I can tell, the= MT events are not needed for this case. >>> So, let's agree on just the two patches I'm going to send to suppor= t >>> "better than nothing" MT-protocol for now. When, later, someone has >>> better ideas, he can send patches to improve MT-protocol >>> support/compliance. Fine? >> >> >> No. I think it is fair to say we tried to make it work properly, but= the (known) >> information about the device is simply not enough. As long as MT doe= s not work >> properly, there is no point in adding it at all - in particular not = an elaborate >> solution. I can see that zoom would work even with a poor MT impleme= ntation, but >> that is not what the MT protocol is about. Maybe one day someone wil= l find the >> missing information somewhere in the packets. >> >> For your usecase, perhaps one should add ABS_ZOOM etcetera instead, = and patch up >> synaptics to use those values. >=20 > No, I do not believe that this is the direcion we should be taking. I= 'd > prefer we export as much information as we can for MT to be useful. A= nd > if we discover some missing pieces in proocol (or future firmware > revisioons will be smarter) we can improve MT support. >=20 That is fine per se, I was simply looking for other options. The questi= on then is how much MT support is needed. For existing applications (read Synap= tics X), there should be no need for MT, so we should be able to wait with that = part until the firmware gets smarter. If the idea is to use something like t= he Multitouch X Driver to enable zoom and rotate, this is where I am hesit= ant, given the current capabilities of the device. Henrik -- 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