From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161271AbWGJAGb (ORCPT ); Sun, 9 Jul 2006 20:06:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161272AbWGJAGb (ORCPT ); Sun, 9 Jul 2006 20:06:31 -0400 Received: from liaag2af.mx.compuserve.com ([149.174.40.157]:31202 "EHLO liaag2af.mx.compuserve.com") by vger.kernel.org with ESMTP id S1161271AbWGJAGa (ORCPT ); Sun, 9 Jul 2006 20:06:30 -0400 Date: Sun, 9 Jul 2006 20:01:26 -0400 From: Chuck Ebbert <76306.1226@compuserve.com> Subject: Re: Magic Alt-SysRq change in 2.6.18-rc1 To: Alan Stern Cc: linux-kernel , Dmitry Torokhov , linux-input Message-ID: <200607092004_MC3-1-C488-137B@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In-Reply-To: On Sun, 9 Jul 2006 17:06:57 -0400, Alan Stern wrote: > > <...> changes in the behavior of Alt-SysRq? > > Before 2.6.18-rc1, I used to be able to use it as follows: > > Press and hold an Alt key, > Press and hold the SysRq key, > Release the Alt key, > Press and release some hot key like S or T or 7, > Repeat the previous step as many times as desired, > Release the SysRq key. > > This scheme doesn't work any more, or if it does, the timing requirements > are now much stricter. In practice I have to hold down all three keys at > the same time; I can't release the Alt key before pressing the hot key. Look at the change history for keyboard.c: [PATCH] fix magic sysrq on strange keyboards Magic sysrq fails to work on many keyboards, particulary most of notebook keyboards. This patch fixes it. The idea is quite simple: Discard the SysRq break code if Alt is still being held down. This way the broken keyboard can send the break code (or the user with a normal keyboard can release the SysRq key) and the kernel waits until the next key is pressed or the Alt key is released. -- Chuck "You can't read a newspaper if you can't read." --George W. Bush