From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261642AbVEZRey (ORCPT ); Thu, 26 May 2005 13:34:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261634AbVEZRey (ORCPT ); Thu, 26 May 2005 13:34:54 -0400 Received: from ylpvm01-ext.prodigy.net ([207.115.57.32]:12949 "EHLO ylpvm01.prodigy.net") by vger.kernel.org with ESMTP id S261642AbVEZRee (ORCPT ); Thu, 26 May 2005 13:34:34 -0400 From: David Brownell To: linux-usb-devel@lists.sourceforge.net Subject: Re: [linux-usb-devel] Re: [linux-pm] potential pitfall? changing configuration while PC in hibernate (fwd) Date: Thu, 26 May 2005 10:34:27 -0700 User-Agent: KMail/1.7.1 Cc: Andrew Morton , cijoml@volny.cz, linux-kernel@vger.kernel.org References: <20050321184512.GA1390@elf.ucw.cz> <200503212310.37801.cijoml@volny.cz> <20050525164701.52a45680.akpm@osdl.org> In-Reply-To: <20050525164701.52a45680.akpm@osdl.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200505261034.28186.david-b@pacbell.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 25 May 2005 4:47 pm, Andrew Morton wrote: > Michal Semler wrote: > > > > It is real stupid, that Linux kernel freezes when simply during hibernate I > > change Bluetooth dongle to USB mouse in my USB port. That is, you unplug the dongle -- breaking the USB power session -- and then plug in a mouse? And the kernel does something other than disconnecting the dongle, and then enumerate a new mouse? That'd be a bug. Somewhere. It'd probably help a lot if the bluetooth USB driver had a suspend() method. It's not clear to me what you mean by "hibernate". If that's an "everything powered off" pseudo-suspend state, then the dongle should always be getting disconnected, and USB always re-enumerated by Linux. Only "real suspend" states, like suspend-to-RAM, can normally maintain USB power sessions. And even then, the device drivers need to be prepared to maintain them ... and do things like stop active I/O requests, and resume them later. You said this was an all-Intel system. So which host controller driver is in use here ... UHCI? EHCI? With RC5 and CONFIG_USB_DEBUG, what do the USB debug messages say is happening? Does CONFIG_USB_SUSPEND change things? Try this with purely modular USB for now. - Dave