From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266258AbUFPML6 (ORCPT ); Wed, 16 Jun 2004 08:11:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266260AbUFPML5 (ORCPT ); Wed, 16 Jun 2004 08:11:57 -0400 Received: from gprs187-64.eurotel.cz ([160.218.187.64]:62848 "EHLO midnight.ucw.cz") by vger.kernel.org with ESMTP id S266258AbUFPMLl (ORCPT ); Wed, 16 Jun 2004 08:11:41 -0400 Date: Wed, 16 Jun 2004 14:11:49 +0200 From: Vojtech Pavlik To: Andrew Morton Cc: Jun Sun , linux-kernel@vger.kernel.org, linux-mips@linux-mips.org Subject: Re: [PATCH] make ps2 mouse work ... Message-ID: <20040616121149.GA9325@ucw.cz> References: <20040615191023.G28403@mvista.com> <20040615205611.1e9cbfcc.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040615205611.1e9cbfcc.akpm@osdl.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 15, 2004 at 08:56:11PM -0700, Andrew Morton wrote: > > I found this problem on a MIPS machine. The problem is > > likely to happen on other register-rich RISC arches too. > > > > cmdcnt needs to be volatile since it is modified by > > irq routine and read by normal process context. > > volatile is not the preferred way to fix this up. This points at either a > locking error in the psmouse driver or a missing "memory" thingy in the > mips port somewhere. > > Please describe the bug which led to this patch. Where was it getting stuck? My current BK tree has this fixed using atomic bitfields, which do compilation and memory barriers. I plan to sync it to Linus post 2.6.7. -- Vojtech Pavlik SuSE Labs, SuSE CR