From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [PATCH 2/5] tsc2007: Add max_rt module parameter. Date: Tue, 17 May 2011 00:24:29 -0700 Message-ID: <20110517072429.GA12015@core.coreip.homeip.net> References: <1305534783-4917-1-git-send-email-thierry.reding@avionic-design.de> <1305534783-4917-2-git-send-email-thierry.reding@avionic-design.de> <20110516165300.GB21232@core.coreip.homeip.net> <20110517065947.GA7521@avionic-0098.mockup.avionic-design.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pv0-f174.google.com ([74.125.83.174]:37962 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752551Ab1EQHYf (ORCPT ); Tue, 17 May 2011 03:24:35 -0400 Received: by pvg12 with SMTP id 12so112516pvg.19 for ; Tue, 17 May 2011 00:24:35 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20110517065947.GA7521@avionic-0098.mockup.avionic-design.de> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Thierry Reding Cc: linux-input@vger.kernel.org, Kwangwoo Lee On Tue, May 17, 2011 at 08:59:47AM +0200, Thierry Reding wrote: > * Dmitry Torokhov wrote: > > Hi Thierry, > > > > On Mon, May 16, 2011 at 10:33:00AM +0200, Thierry Reding wrote: > > > Finger touch events or very quick stylus events on low-quality panels > > > can cause the tsc2007 to read bogus values. Looking at oscilloscope > > > snapshots, this seems to be caused by the touch event disappearing > > > during the measurements. These bogus values result in misclicks, where > > > the X and Y values deviate from the real position. > > > > > > Most of these misclicks can be filtered out by setting a low enough > > > threshold for the maximum resistance (which is loosely the inverse of > > > the pressure) allowed to consider a set of values valid. Since this > > > behaviour is largely dependent on the type and quality of the panel, > > > this commit introduces the max_rt parameter. The default value is kept > > > at MAX_12BIT. > > > > I expect that the values, once selected, will not be changed for a given > > panel, so why don't we pass max_rt (and poll_delay and poll_interval) vi > > platform (board) data instead of being module parameters? > > How do I best handle keeping the default values? Should I check whether the > value has been set at all in the platform data and set the default otherwise? > That would reserve the value 0 as special. Or should I just assume that all > the values must be set explicitly? We need to try and keep being compatible with existing setups. Treating 0 as "unset" seems reasonable. Thanks. -- Dmitry