From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264455AbTLLCRs (ORCPT ); Thu, 11 Dec 2003 21:17:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264456AbTLLCRs (ORCPT ); Thu, 11 Dec 2003 21:17:48 -0500 Received: from mta7.pltn13.pbi.net ([64.164.98.8]:7657 "EHLO mta7.pltn13.pbi.net") by vger.kernel.org with ESMTP id S264455AbTLLCRr (ORCPT ); Thu, 11 Dec 2003 21:17:47 -0500 Message-ID: <3FD92632.50200@pacbell.net> Date: Thu, 11 Dec 2003 18:21:38 -0800 From: David Brownell User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20030225 X-Accept-Language: en-us, en, fr MIME-Version: 1.0 To: Duncan Sands CC: Alan Stern , Vince , "Randy.Dunlap" , mfedyk@matchmail.com, zwane@holomorphy.com, linux-kernel@vger.kernel.org, USB development list Subject: Re: [linux-usb-devel] Re: [OOPS, usbcore, releaseintf] 2.6.0-test10-mm1 References: <200312081859.03773.baldrick@free.fr> In-Reply-To: <200312081859.03773.baldrick@free.fr> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > PS: Here is the patch that fixed the original usbfs Oops, but gained the new > one Vince reported: Good -- more locks vanishing from usbcore; it's about time! This is a case where fewer locks are better. My main patch feedback here would be that it should merge most of the usbfs patch I sent (second URL below). There's a driver model locking requirement that you didn't know about, it needs to bubble up (subsys.rwsem writelock must be held if you're going to change driver bindings). And there were a few other rough spots, which I think you've mentioned (and I don't think they were new issues). The more I think about it, the more I like your idea of changing device->serialize to be an rwsem. Changing config, or resetting the device, would get the writelock. All other uses should share, with readlocks -- that's the right model. Likely not before 2.6.1 though ... ;) - Dave [1] http://marc.theaimsgroup.com/?l=linux-usb-devel&m=107100212612153&w=2 [2] http://marc.theaimsgroup.com/?l=linux-usb-devel&m=107102580404037&w=2