From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753052Ab1GESUD (ORCPT ); Tue, 5 Jul 2011 14:20:03 -0400 Received: from adelie.canonical.com ([91.189.90.139]:58889 "EHLO adelie.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751847Ab1GESUB (ORCPT ); Tue, 5 Jul 2011 14:20:01 -0400 Message-ID: <4E1355CB.9070504@canonical.com> Date: Tue, 05 Jul 2011 11:19:55 -0700 From: Chase Douglas User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.17) Gecko/20110516 Thunderbird/3.1.10 MIME-Version: 1.0 To: Henrik Rydberg CC: Daniel Kurtz , dmitry.torokhov@gmail.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 Subject: Re: [PATCH 05/12] Input: synaptics - process button bits in AGM packets References: <1309324042-22943-1-git-send-email-djkurtz@chromium.org> <1309324042-22943-6-git-send-email-djkurtz@chromium.org> <20110704212404.GC23915@polaris.bitmath.org> <20110705181843.GA29296@polaris.bitmath.org> In-Reply-To: <20110705181843.GA29296@polaris.bitmath.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/05/2011 11:18 AM, Henrik Rydberg wrote: >>> Any particular reason to move these and leave them unassigned for clickpads? >> >> Yes. The current implementation incorrectly parses the x, y, z of AGM >> packets and assigns junk values to the corresponding fields of the >> temporary hw struct. Luckily, this struct is then just discarded upon >> return (synaptics_parse_hw_state returns 1 causing >> synaptics_process_packet() to exit immediately). >> >> Instead, this patch parses the w value first to determine the packet >> type, and then use this packet type information to parse the remaining >> position and pressure fields correctly... >> >> Notice that the "else" clause is taken for SGM packets (w != 2), even >> for clickpads. > > Functionally, there is no difference between assigning new junk or > reusing old junk, hence that part of the patch is not strictly needed. True, it's not necessary, but I do like the new flow better. I was reviewing the patch myself when I started wondering why we ever assigned junk that was incorrect. I think this will help clean up the code and make it more readable. -- Chase