From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753991Ab1GEXDJ (ORCPT ); Tue, 5 Jul 2011 19:03:09 -0400 Received: from smtp-out.google.com ([74.125.121.67]:29349 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751741Ab1GEXDH (ORCPT ); Tue, 5 Jul 2011 19:03:07 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=dkim-signature:mime-version:sender:in-reply-to:references:from: date:x-google-sender-auth:message-id:subject:to:cc:content-type:x-system-of-record; b=MDTrsltpKUU9WJ4jFcHiFcmWhd3V5UQL8oR/LnGtTEOJ+4HFKVVvIv0mcVwa4q1le /j7dXADo66nAW/qutz57g== MIME-Version: 1.0 In-Reply-To: <20110705180712.GA29224@polaris.bitmath.org> References: <1309324042-22943-1-git-send-email-djkurtz@chromium.org> <1309324042-22943-3-git-send-email-djkurtz@chromium.org> <20110704210838.GA23915@polaris.bitmath.org> <20110705180712.GA29224@polaris.bitmath.org> From: Daniel Kurtz Date: Wed, 6 Jul 2011 07:02:43 +0800 X-Google-Sender-Auth: 1PuACCEbuX2oorfZfJoIMhrAtWk Message-ID: Subject: Re: [PATCH 02/12] Input: synaptics - do not invert y if 0 To: Henrik Rydberg Cc: dmitry.torokhov@gmail.com, chase.douglas@canonical.com, rubini@cvml.unipv.it, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, derek.foreman@collabora.co.uk, daniel.stone@collabora.co.uk, olofj@chromium.org Content-Type: text/plain; charset=ISO-8859-1 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 6, 2011 at 2:07 AM, Henrik Rydberg wrote: >> > > In some cases, however, y = 0 is sent by the touchpad. >> > > In these cases, the kernel driver should not invert, and just report 0. >> > > >> > > This patch also refactors the inversion into a macro, and moves it >> > > into packet processing instead of during position reporting. >> > >> > The patch seems to invert the current output? >> >> By 'current' do you mean referenced from the previous implementation? >> Or referenced from the raw input. >> It does indeed invert the raw input. >> This is the same as the previous implementation did. >> The difference is that it does not also invert the special 'y=0' into >> an arbitrarily large value. >> Is this your concern? > > It would be clearer to just change the argument of the > input_report_abs() instances, would it not? An explanation why zero, > outside the value range, should be output also needs a rationale. It > would seem such packets should be masked somehow. Actually, I think it is clearer to change all the y's in one function, during parsing, rather than scattered about in various output functions. I'm sorry, I think I was misleading in my commit message. This change doesn't affect how packets get masked. The y=0 is not handled differently now that it is no longer inverted. If it wasn't sent to userspace before, it still won't be sent. The older inverted y=0 was also, by definition, out of range, so hopefully those packets are masked, and continue to be masked. Not inverting y=0 just makes it a bit easier to debug the driver, by slightly more accurately parsing the incoming raw data. > > Thanks, > Henrik >