From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932621AbWFCL4n (ORCPT ); Sat, 3 Jun 2006 07:56:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932622AbWFCL4n (ORCPT ); Sat, 3 Jun 2006 07:56:43 -0400 Received: from smtp109.sbc.mail.mud.yahoo.com ([68.142.198.208]:32437 "HELO smtp109.sbc.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S932621AbWFCL4m (ORCPT ); Sat, 3 Jun 2006 07:56:42 -0400 From: Dmitry Torokhov To: Arjan van de Ven Subject: Re: [patch] Declare explicit, hardware based lock ranking in serio Date: Sat, 3 Jun 2006 07:56:39 -0400 User-Agent: KMail/1.9.1 Cc: Andrew Morton , linux-kernel@vger.kernel.org, mingo@redhat.com, arjanv@redhat.com, Linux Portal References: <20060602161354.687168de.akpm@osdl.org> <1149324621.3109.16.camel@laptopd505.fenrus.org> In-Reply-To: <1149324621.3109.16.camel@laptopd505.fenrus.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200606030756.39861.dtor_core@ameritech.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Saturday 03 June 2006 04:50, Arjan van de Ven wrote: > > Thanks. > > > > So we're taking ps2->cmd_mutex and then we're recurring back into > > ps2_command() and then taking ps2->serio->cmd_mutex. > > > > I suspect that's all correct/natural/expected and needs another > > make-lockdep-shut-up patch. > > > The PS/2 code has a natural device order and there is a one level > recursion in this device order in terms of the cmd_mutex; annotate > this explicit recursion as ok > It is not necessarily single depth - one could have 2 or more pass-through ports chained together, although currently in kernel we only have Synaptics pass-through. If we were ever to implement pass-through port for IBMs trackpoints then we'd have: Synaptics<->pass-through<->TP<->pass-through<->some mouse -- Dmitry