From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753558Ab0IMP6G (ORCPT ); Mon, 13 Sep 2010 11:58:06 -0400 Received: from cantor.suse.de ([195.135.220.2]:47906 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752250Ab0IMP6E (ORCPT ); Mon, 13 Sep 2010 11:58:04 -0400 Date: Mon, 13 Sep 2010 08:56:08 -0700 From: Greg KH To: Alan Stern Cc: Jiri Slaby , phil@ipom.com, stable@kernel.org, USB list , Linux kernel mailing list Subject: Re: [34-stable regression] USB delay init quirk causes device events loss Message-ID: <20100913155608.GA27853@suse.de> References: <4C8E3C40.50808@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 13, 2010 at 11:37:49AM -0400, Alan Stern wrote: > On Mon, 13 Sep 2010, Jiri Slaby wrote: > > > On 09/13/2010 04:48 PM, Alan Stern wrote: > > > On Mon, 13 Sep 2010, Jiri Slaby wrote: > > >> In other words, what I could do is to add some printks into > > >> hub_port_connect_change if that's called at all. If you need some > > >> thorough debugging printks, please send me a patch to test instead. > > > > > > Hmm. I'd prefer to explain how it's all supposed to work and let you > > > figure out where best to look. Or try to debug it myself. Does this > > > happen with other sorts of USB devices as well, or just wacom? > > > > With some sort of devices (I cannot reproduce myself). It's unrelated to > > wacom -- people with wacom were unable to even start X with this kernel. > > If you look at the bugreport, there are several examples: > > ID 046d:c517 Logitech, Inc. LX710 Cordless Desktop Laser defunct > > Microsoft USB keyboard defunct x Logitech mice OK > > 046a:0021 Cherry GmbH keyboard defunct > > logitech wireless laptop mouse defunct > > A$Tech wireless laptop mouse defunct > > TypeMatrix USB 2030 (ID : 1e54:2030) defunct > > Okay, I see the problem. By moving usb_detect_quirks earlier, we end > up calling usb_disable_autosuspend too soon -- before the > pm_runtime_enable call in usb_new_device. In 2.6.35 this doesn't > matter because the implementation of usb_autosuspend_device has > changed. > > So yes, in the end it looks like the best course is to revert this > patch from 2.6.34.stable. This is unfortunate but I don't see any way > around it without making changes that aren't present in the current > kernel. For example, the pm_runtime_set_active and pm_runtime_enable > calls could also be moved from usb_new_device into > hub_port_connect_change. Ok, I'll go revert that from the .34-stable tree and do a new release, as it's not nice to have a broken tree out there. thanks, greg k-h