From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265958AbUFDTxs (ORCPT ); Fri, 4 Jun 2004 15:53:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265959AbUFDTxr (ORCPT ); Fri, 4 Jun 2004 15:53:47 -0400 Received: from mail.kroah.org ([65.200.24.183]:32739 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S265958AbUFDTxl (ORCPT ); Fri, 4 Jun 2004 15:53:41 -0400 Date: Fri, 4 Jun 2004 12:52:47 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, "David A. Desrosiers" Cc: linux-usb-devel@lists.sourceforge.net Subject: Re: USBDEVFS_RESET deadlocks USB bus. Message-ID: <20040604195247.GA12688@kroah.com> References: <20040604193911.GA3261@babylon.d2dc.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040604193911.GA3261@babylon.d2dc.net> User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 04, 2004 at 03:39:11PM -0400, Zephaniah E. Hull wrote: > Starting at 2.6.7-rc1 or so (that is when we first noticed it) the new > pilot-link libusb back end started deadlocking the entire USB bus that > the palm device was on. > > I have finally tracked it down to happening when we make the > USBDEVFS_RESET ioctl, we never return from it and from that point on the > bus in question is completely dead, no processing is done, no > notifications of devices being plugged in or unplugged. > > This is still happening in 2.6.7-rc2-mm1. > > It seems to happen with both the UHCI and OHCI back ends, so it is > probably above that. > > Given that there were heavy locking changes, I suspect that the case in > question got screwed up somehow. This needs to go to the linux-usb-devel list, now CC: Anyway, can you look at the output of SysRq-T and see where the processes are hung? thanks, greg k-h