From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757601AbYLFMkq (ORCPT ); Sat, 6 Dec 2008 07:40:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755522AbYLFMkj (ORCPT ); Sat, 6 Dec 2008 07:40:39 -0500 Received: from cavan.codon.org.uk ([93.93.128.6]:57190 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752331AbYLFMki (ORCPT ); Sat, 6 Dec 2008 07:40:38 -0500 Date: Sat, 6 Dec 2008 12:40:31 +0000 From: Matthew Garrett To: Parav Pandit Cc: Linux kernel Subject: Re: mechanism to syncronise device access from user and kernel Message-ID: <20081206124031.GB4821@srcf.ucam.org> References: <377462.57009.qm@web30107.mail.mud.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <377462.57009.qm@web30107.mail.mud.yahoo.com> User-Agent: Mutt/1.5.12-2006-07-14 X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mjg59@codon.org.uk X-SA-Exim-Scanned: No (on vavatch.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 05, 2008 at 10:28:27AM -0800, Parav Pandit wrote: > Hi, > > I have a device whose registers are accessed by driver as well as user space application via mmap() area. > > How to synchronize the access (avoid race condition) between user space driver and kernel mode driver, in single CPU and multi-CPU systems? Rewrite userspace to use the kernel driver? -- Matthew Garrett | mjg59@srcf.ucam.org