From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263166AbUE3Lxk (ORCPT ); Sun, 30 May 2004 07:53:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263174AbUE3Lxk (ORCPT ); Sun, 30 May 2004 07:53:40 -0400 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:55561 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S263166AbUE3Lxj (ORCPT ); Sun, 30 May 2004 07:53:39 -0400 Date: Sun, 30 May 2004 12:53:30 +0100 From: Russell King To: Sau Dan Lee Cc: Vojtech Pavlik , linux-kernel@vger.kernel.org Subject: Re: keyboard problem with 2.6.6 Message-ID: <20040530125330.A25212@flint.arm.linux.org.uk> Mail-Followup-To: Sau Dan Lee , Vojtech Pavlik , linux-kernel@vger.kernel.org References: <20040530111847.GA1377@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: ; from danlee@informatik.uni-freiburg.de on Sun, May 30, 2004 at 01:40:03PM +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 30, 2004 at 01:40:03PM +0200, Sau Dan Lee wrote: > Now, what prevents people from connecting terminals to a computer via > the PS/2 mouse port? Apart from electrically blowing the PS/2 port, the data format of PS/2 is well defined and fixed, whereas a UART (8250-based) port is more flexible. PS/2 also has the idea of acknowledgement from the peripheral device for each byte transferred, and is synchronous, whereas UARTs have no acknowledgement and are asyncrhonous. So, any thought that the two ports are similar compatible with each other, either from the electrical or protocol points of view is just a dead loss. How do these mice work on both ports then? They can detect which port they're connected to and the electronics inside automatically configures itself depending on which port they're connected to. > Your approach in the input system completely rules out this > possibility. As from above, its more than just the input system - its the protocol and electrical characteristics which completely rules out the possibility - which in turn makes it nonsensible to support such an idea in software. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 PCMCIA - http://pcmcia.arm.linux.org.uk/ 2.6 Serial core