Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754889AbWKQIMT (ORCPT ); Fri, 17 Nov 2006 03:12:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754891AbWKQIMT (ORCPT ); Fri, 17 Nov 2006 03:12:19 -0500 Received: from s131.mittwaldmedien.de ([62.216.178.31]:58199 "EHLO s131.mittwaldmedien.de") by vger.kernel.org with ESMTP id S1754889AbWKQIMT convert rfc822-to-8bit (ORCPT ); Fri, 17 Nov 2006 03:12:19 -0500 From: Holger Schurig To: Daniel Ritz Subject: Re: [PATCH] usb: generic calibration support Date: Fri, 17 Nov 2006 09:12:29 +0100 User-Agent: KMail/1.9.5 Cc: daniel.ritz@gmx.ch, linux-kernel@vger.kernel.org, linux-usb-devel@lists.sourceforge.net, Dmitry Torokhov References: <200611161125.38901.hs4233@mail.mn-solutions.de> <200611170024.33248.daniel.ritz-ml@swissonline.ch> In-Reply-To: <200611170024.33248.daniel.ritz-ml@swissonline.ch> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200611170912.29317.hs4233@mail.mn-solutions.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2002 Lines: 50 > sorry, but i have to give you a big NACK on that one: Hehe, I actually anticipated this NACK :-) > - no more modparam: it should be per-device sysfs attributes > ? (swap_xy is basically only for touchkitusb compatibility and > shoud be converted to per-device sysfs attribute as well. i > ? just never got to do it) That would be okay for me. > - calibration can be handled in userspace just fine Yes it can, and that is the most convinging argument against my patch. However, user-space calibration often sucks. For example, in X11 the calibration values are stored in /etc/X11/xorg.conf, so a calibration program has to parse & write that file. And I've seen binary-only-calibration programs from vendors use /etc/X11/XF86Config, which doesn't exist here. Anyway, once you've calibrated you have to restart X-Windows, so you need to terminate all running X applications just because of a silly re-calibration. Not nice. A calibration at kernel level (may it be input level or driver level) doesn't have this problem. I can make the level persistent via udev, modules.conf or other means. Even when I have a frame-buffer based calibration utility, the calibration would be OK for X11 or GTK/DirectFB as well. For me, this speaks against "Calibration is purely a user-space problem". > - even for in-kernel it's in the wrong place. there are other > devices that report raw absolute data...so it would belong to > the input layer Suppose I have a graphics tabled and a touchscreen connected at the same time. Can I distinguish this easily at the input layer level? I can very easily distinguish this at the device driver level. After all, the individual calibration parameters are a property of this individual device. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/