Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262584AbVDGUIe (ORCPT ); Thu, 7 Apr 2005 16:08:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262586AbVDGUIe (ORCPT ); Thu, 7 Apr 2005 16:08:34 -0400 Received: from digitalimplant.org ([64.62.235.95]:62144 "HELO digitalimplant.org") by vger.kernel.org with SMTP id S262584AbVDGUIZ (ORCPT ); Thu, 7 Apr 2005 16:08:25 -0400 Date: Thu, 7 Apr 2005 13:08:17 -0700 (PDT) From: Patrick Mochel X-X-Sender: mochel@monsoon.he.net To: Alan Stern cc: David Brownell , Kernel development list Subject: Re: klists and struct device semaphores In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1435 Lines: 37 On Wed, 6 Apr 2005, Alan Stern wrote: > The patch looks good. But isn't there still a problem with > device_release_driver()? It doesn't wait for the klist_node to be removed > from the klist before unlocking the device and moving on. As a result, if > another driver was waiting to bind to the device you would corrupt the > list pointers, by calling klist_add_tail() for the new driver before > klist_release() had run for the old driver. > > I'll be interested to see how you manage to solve this. The only way I > can think of is to avoid using driver_for_each_device() in > driver_detach(). I had implemented something along the lines of what you suggested in a previous email: - Add flag to klist_node: n_attached. - Use that in klist_node_attached() - Check during klist_next(), and skip nodes that have been removed. - Reset flag during klist_del(). Based on the deadlock that occurs when using klist_remove() during an iteration over that the list, and the common indirect usage of it (parents and buses unregistering devices, drivers unbinding devices), I've just removed klist_remove() and the embedded completion. I'll post updated patches soon. Thanks, Pat - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/