From mboxrd@z Thu Jan 1 00:00:00 1970 From: Henrik Rydberg Subject: Re: [PATCH 1/3] Input: Fixed ABS_MT_TOUCH_MINOR scale factor in BCM5974 multitouch driver Date: Thu, 21 Nov 2013 10:05:01 +0100 Message-ID: <528DCCBD.80009@euromail.se> References: <1384988052-31898-1-git-send-email-linux@schoeller.se> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from smtprelay-b21.telenor.se ([195.54.99.212]:33475 "EHLO smtprelay-b21.telenor.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753751Ab3KUJBs (ORCPT ); Thu, 21 Nov 2013 04:01:48 -0500 In-Reply-To: <1384988052-31898-1-git-send-email-linux@schoeller.se> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: =?ISO-8859-1?Q?Friedrich_Sch=F6ller?= , Dmitry Torokhov , linux-input@vger.kernel.org Cc: linux-kernel@vger.kernel.org Hi Friedrich, > On wellspring3 devices ABS_MT_TOUCH_MINOR was sometimes reported bigger than > ABS_MT_TOUCH_MAJOR. This is fixed by rescaling ABS_MT_TOUCH_MINOR by a factor of > 0.85 instead of 2. Excessive tapping on the trackpad shows this to be the right > value. Circular touches should now lead to values for ABS_MT_TOUCH_MAJOR and > ABS_MT_TOUCH_MINOR that are similar, with ABS_MT_TOUCH_MINOR never greater than > ABS_MT_TOUCH_MAJOR. > --- > drivers/input/mouse/bcm5974.c | 20 +++++++++++++++++--- > 1 file changed, 17 insertions(+), 3 deletions(-) The major/minor scales are following the aspect ratio of the device, and as such it could happen that minor > major. Most userland drivers do not use the finger width limits, which are estimates, but only the device axes limit, which are accurate. Also, we cannot have floats in the kernel. I would consider a patch which tries to make the finger widths more accurate, but all in all, I think this problem is best solved in userland. Thanks, Henrik