From mboxrd@z Thu Jan 1 00:00:00 1970 From: Henrik Rydberg Subject: Re: [PATCH 2/2] elantech: Report multitouch with proper ABS_MT messages Date: Wed, 05 May 2010 20:26:20 +0200 Message-ID: <4BE1B84C.1040903@euromail.se> References: <4BE1629E.50901@tudelft.nl> <20100505163832.GA7337@core.coreip.homeip.net> <4BE1B289.2040204@euromail.se> <4BE1B595.9090705@tudelft.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from ch-smtp03.sth.basefarm.net ([80.76.149.214]:52536 "EHLO ch-smtp03.sth.basefarm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757371Ab0EES0h (ORCPT ); Wed, 5 May 2010 14:26:37 -0400 In-Reply-To: <4BE1B595.9090705@tudelft.nl> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: =?ISO-8859-1?Q?=C9ric_Piel?= Cc: Dmitry Torokhov , Florian Ragwitz , "linux-input@vger.kernel.org" =C9ric Piel wrote: > Op 05-05-10 20:01, Henrik Rydberg schreef: >> Dmitry Torokhov wrote: >>>> @@ -253,7 +253,6 @@ static void elantech_report_absolute_v2(struct= psmouse *psmouse) >>>> =20 >>>> /* byte 0: n1 n0 . . . . R L */ >>>> fingers =3D (packet[0] & 0xc0) >> 6; >>>> - input_report_key(dev, BTN_TOUCH, fingers !=3D 0); >>> Mousedev works a tad better if BTN_TOUCH is reported first. Otherwi= se >>> looks good. >>> >>> Henrik, should we report "tool width" as ABS_MT_WIDTH_MAJOR? >> I might be missing some context here, I see no prior use of width in= the driver. >> The answer is either ABS_MT_TOUCH_MAJOR or ABS_MT_WIDTH_MAJOR depend= ing on how >> the width is actually computed. Generally, it makes little sense to = have >> ABS_MT_WIDTH_MAJOR (width of approaching finger) without ABS_MT_TOUC= H_MAJOR >> (width of touching finger), but it is ok to have only ABS_MT_TOUCH_M= AJOR. Things >> like thumb detection requires both values to be reliable. > Ok, so it seems in this case, ABS_MT_TOUCH_MAJOR is the most > appropriate... if we care at all. >=20 > Let me give you some more details. From what is seems, the hardware c= an > reports the width of a touch, but only when there is one single touch= =2E > So far we report it via ABS_TOOL_WIDTH. When there is 2 or 3 touches, > the width is unknown. So the precise question is: > Should we report also ABS_MT_TOUCH_MAJOR in addition to ABS_TOOL_WIDT= H, > whenever it is known (ie: one finger), or just not bother and only > report ABS_TOOL_WIDTH? With only partial information available it will not be of much use anyw= ay, so omitting ABS_MT_TOUCH is probably best. The ABS_TOOL_WIDTH will most li= kely not be used by a driver either (it wont in the Multitouch X Driver anyways)= =2E The synaptics driver cares for palm detection, but the scale has to be very= specific to work properly (i.e., requires testing with synaptics to be useful). 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