From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755341AbYBTWS0 (ORCPT ); Wed, 20 Feb 2008 17:18:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755140AbYBTWSD (ORCPT ); Wed, 20 Feb 2008 17:18:03 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:60146 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755219AbYBTWSA (ORCPT ); Wed, 20 Feb 2008 17:18:00 -0500 From: "Rafael J. Wysocki" To: Alan Stern Subject: Re: [Bug 10030] Suspend doesn't work when SD card is inserted Date: Wed, 20 Feb 2008 23:15:48 +0100 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) Cc: Pierre Ossman , Zdenek Kabelac , Kernel development list References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200802202315.49032.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, 20 of February 2008, Alan Stern wrote: > On Wed, 20 Feb 2008, Pierre Ossman wrote: > > > > And why not simply fail the suspend if the resume routine doesn't exist > > > and the suspend routine does? Maybe with an error message in the > > > system log. > > > > For the asymmetric case, I guess that would do. But I still want to remove devices when the bus handler has no suspend handling. > > Then it appears the correct approach is to use the new > device_pm_schedule_removal() routine. It schedules the removal of a > suspended device for a time when the system suspend is over. Well, below is an uncompiled and untested but illustrating the idea that might allow people not to bother with device_pm_schedule_removal() explicitly and can fix the issue at hand. [There are some cases that need handling and are not covered here.] Please have a look. Thanks, Rafael --- drivers/base/core.c | 5 ++++- drivers/base/power/main.c | 22 ++++++++++++++++++++++ drivers/base/power/power.h | 5 +++++ 3 files changed, 31 insertions(+), 1 deletion(-) Index: linux-2.6/drivers/base/power/main.c =================================================================== --- linux-2.6.orig/drivers/base/power/main.c +++ linux-2.6/drivers/base/power/main.c @@ -59,6 +59,26 @@ static DECLARE_RWSEM(pm_sleep_rwsem); int (*platform_enable_wakeup)(struct device *dev, int is_on); +static struct task_struct *suspending_task; +static DEFINE_MUTEX(suspending_task_mtx); + +bool in_suspend_context(void) +{ + bool result; + + mutex_lock(&suspending_task_mtx); + result = (suspending_task == current); + mutex_unlock(&suspending_task_mtx); + return result; +} + +static void set_suspending_task(struct task_struct *task) +{ + mutex_lock(&suspending_task_mtx); + suspending_task = task; + mutex_unlock(&suspending_task_mtx); +} + /** * device_pm_add - add a device to the list of active devices * @dev: Device to be added to the list @@ -272,6 +292,7 @@ static void dpm_resume(void) mutex_lock(&dpm_list_mtx); } mutex_unlock(&dpm_list_mtx); + set_suspending_task(NULL); } /** @@ -460,6 +481,7 @@ static int dpm_suspend(pm_message_t stat { int error = 0; + set_suspending_task(current); mutex_lock(&dpm_list_mtx); while (!list_empty(&dpm_locked)) { struct list_head *entry = dpm_locked.prev; Index: linux-2.6/drivers/base/core.c =================================================================== --- linux-2.6.orig/drivers/base/core.c +++ linux-2.6/drivers/base/core.c @@ -1162,7 +1162,10 @@ void device_destroy(struct class *class, dev = class_find_device(class, &devt, __match_devt); if (dev) { put_device(dev); - device_unregister(dev); + if (in_suspend_context()) + device_pm_schedule_removal(dev); + else + device_unregister(dev); } } EXPORT_SYMBOL_GPL(device_destroy); Index: linux-2.6/drivers/base/power/power.h =================================================================== --- linux-2.6.orig/drivers/base/power/power.h +++ linux-2.6/drivers/base/power/power.h @@ -11,6 +11,7 @@ static inline struct device *to_device(s return container_of(entry, struct device, power.entry); } +extern bool in_suspend_context(void); extern void device_pm_add(struct device *); extern void device_pm_remove(struct device *); extern int pm_sleep_lock(void); @@ -18,6 +19,10 @@ extern void pm_sleep_unlock(void); #else /* CONFIG_PM_SLEEP */ +static inline bool in_suspend_context(void) +{ + return false; +} static inline void device_pm_add(struct device *dev) {