Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759749Ab0HLMH0 (ORCPT ); Thu, 12 Aug 2010 08:07:26 -0400 Received: from cantor.suse.de ([195.135.220.2]:50572 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753240Ab0HLMHX (ORCPT ); Thu, 12 Aug 2010 08:07:23 -0400 Date: Thu, 12 Aug 2010 14:07:21 +0200 (CEST) From: Jiri Kosina To: Markus Trippelsdorf Cc: Heinz Diehl , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-input@vger.kernel.org, Alan Ott , Arnd Bergmann Subject: Re: [BUG] object: is not initialized, yet kobject_put() is being called In-Reply-To: <20100812115657.GA1611@arch.tripp.de> Message-ID: References: <20100810210941.GA7938@fritha.org> <20100810223215.GA1609@arch.tripp.de> <20100812091659.GA1591@arch.tripp.de> <20100812113624.GB1591@arch.tripp.de> <20100812114513.GA1584@arch.tripp.de> <20100812115657.GA1611@arch.tripp.de> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3258 Lines: 72 On Thu, 12 Aug 2010, Markus Trippelsdorf wrote: > > > > > > Guys, could you please send me your .config with which you are > > > > > > experiencing the problem, so that I can try to reproduce it with it? > > > > > > > > > > Attached. > > > > > > > > So I had to add support for HW of mine (SATA_VIA, PATA_VIA, disabled the > > > > radeon firmware stuff, and, most importantly, enabled UHCI, which is what > > > > is on machine I am using now for testing), and disconnect-connect cycle > > > > works nicely: > > > > > > > > usb 3-2: USB disconnect, address 3 > > > > usb 3-2: new low speed USB device using uhci_hcd and address 4 > > > > input: mouse USB mouse with wheel as /devices/pci0000:00/0000:00:10.1/usb3/3-2/3-2:1.0/input/input6 > > > > generic-usb 0003:05B8:3091.0004: input,hidraw0: USB HID v1.10 Mouse [mouse USB mouse with wheel] on usb-0000:00:10.1-2/input0 > > > > input: mouse USB mouse with wheel as /devices/pci0000:00/0000:00:10.1/usb3/3-2/3-2:1.1/input/input7 > > > > generic-usb 0003:05B8:3091.0005: input,hidraw1: USB HID v1.10 Keyboard [mouse USB mouse with wheel] on usb-0000:00:10.1-2/input1 > > > > > > > > so still no BUG from kobject refcounting, and the hidraw numbers are the > > > > same. The major difference seems to be that I am using UHCI and you have > > > > your HID devices connected through OHCI, is that correct? > > > > > > Correct. And I should add that it very easy to reproduce here; just > > > disconnecting the usb receiver triggers the WARNING. > > > > Disabling USB_HIDDEV in my .config solves the problem (there is no > > WARNING anymore when disconnecting the receiver). > > Reverting bd25f4dd6972755579d0ea50d1a5ace2e9b00d1a with USB_HIDDEV > enabled also solves the problem. So there must be a bug in that patch: > > commit bd25f4dd6972755579d0ea50d1a5ace2e9b00d1a > Author: Arnd Bergmann > Date: Sun Jul 11 15:34:05 2010 +0200 > > HID: hiddev: use usb_find_interface, get rid of BKL > > This removes the private hiddev_table in the usbhid > driver and changes it to use usb_find_interface > instead. > > The advantage is that we can avoid the race between > usb_register_dev and usb_open and no longer need the > big kernel lock. > > This doesn't introduce race condition -- the intf pointer could be > invalidated only in hiddev_disconnect() through usb_deregister_dev(), > but that will block on minor_rwsem and not actually remove the device > until usb_open(). > > Signed-off-by: Arnd Bergmann > Cc: Jiri Kosina > Cc: "Greg Kroah-Hartman" > Signed-off-by: Jiri Kosina Thanks, I had my suspicion about this commit (that's why I asked to you verify with CONFIG_USB_HIDDEV turned off as well). Adding Arnd to CC and will look into it myself as well soon. Arnd, the complete thread can be found at http://lkml.org/lkml/2010/8/10/280 -- Jiri Kosina SUSE Labs, Novell Inc. -- 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/