From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753915Ab1KOBFk (ORCPT ); Mon, 14 Nov 2011 20:05:40 -0500 Received: from out2.smtp.messagingengine.com ([66.111.4.26]:58964 "EHLO out2.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752900Ab1KOBFh (ORCPT ); Mon, 14 Nov 2011 20:05:37 -0500 X-Sasl-enc: 11WTaSY5AgTiLIOGM6YpX+8jtjt8y56nMZaCcn1t5prK 1321319136 Date: Mon, 14 Nov 2011 16:59:51 -0800 From: Greg KH To: "Rafael J. Wysocki" Cc: Peter Chen , gregkh@suse.de, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, stern@rowland.harvard.edu, hzpeterchen@gmail.com Subject: Re: [PATCH 1/1] driver core: disable device's runtime pm during shutdown Message-ID: <20111115005951.GB26360@kroah.com> References: <1321231380-11631-1-git-send-email-peter.chen@freescale.com> <201111142327.37524.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201111142327.37524.rjw@sisk.pl> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 14, 2011 at 11:27:37PM +0100, Rafael J. Wysocki wrote: > On Monday, November 14, 2011, Peter Chen wrote: > > There may be an issue when the user issue "reboot/shutdown" command, then > > the device has shut down its hardware, after that, this runtime-pm featured > > device's driver will probably be scheduled to do its suspend routine, > > and at its suspend routine, it may access hardware, but the device has > > already shutdown physically, then the system hang may be occurred. > > > > I ran out this issue using an auto-suspend supported USB devices, like > > 3G modem, keyboard. The usb runtime suspend routine may be scheduled > > after the usb controller has been shut down, and the usb runtime suspend > > routine will try to suspend its roothub(controller), it will access > > register, then the system hang occurs as the controller is shutdown. > > Signed-off-by: Peter Chen > > Greg, do you want me to take this one? Please do: Acked-by: Greg Kroah-Hartman thanks, greg k-h