From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756522Ab1KNWZV (ORCPT ); Mon, 14 Nov 2011 17:25:21 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:39276 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752354Ab1KNWZU (ORCPT ); Mon, 14 Nov 2011 17:25:20 -0500 From: "Rafael J. Wysocki" To: Peter Chen , gregkh@suse.de Subject: Re: [PATCH 1/1] driver core: disable device's runtime pm during shutdown Date: Mon, 14 Nov 2011 23:27:37 +0100 User-Agent: KMail/1.13.6 (Linux/3.1.0-rc10+; KDE/4.6.0; x86_64; ; ) Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, stern@rowland.harvard.edu, hzpeterchen@gmail.com References: <1321231380-11631-1-git-send-email-peter.chen@freescale.com> In-Reply-To: <1321231380-11631-1-git-send-email-peter.chen@freescale.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-2" Content-Transfer-Encoding: 7bit Message-Id: <201111142327.37524.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? Rafael > --- > drivers/base/core.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index bc8729d..78445f4 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -22,6 +22,7 @@ > #include > #include > #include > +#include > > #include "base.h" > #include "power/power.h" > @@ -1742,6 +1743,8 @@ void device_shutdown(void) > */ > list_del_init(&dev->kobj.entry); > spin_unlock(&devices_kset->list_lock); > + /* Disable all device's runtime power management */ > + pm_runtime_disable(dev); > > if (dev->bus && dev->bus->shutdown) { > dev_dbg(dev, "shutdown\n"); >