Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764514AbYCEXZw (ORCPT ); Wed, 5 Mar 2008 18:25:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757963AbYCEXZi (ORCPT ); Wed, 5 Mar 2008 18:25:38 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:33102 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756839AbYCEXZg (ORCPT ); Wed, 5 Mar 2008 18:25:36 -0500 From: "Rafael J. Wysocki" To: Alan Stern Subject: Re: [RFC][PATCH] PM: Make PM core handle device registrations concurrent with suspend/hibernation Date: Thu, 6 Mar 2008 00:24:28 +0100 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) Cc: pm list , Alexey Starikovskiy , Pavel Machek , LKML 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: <200803060024.28850.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4093 Lines: 132 On Wednesday, 5 of March 2008, Alan Stern wrote: > On Wed, 5 Mar 2008, Rafael J. Wysocki wrote: > > > On Wednesday, 5 of March 2008, Alan Stern wrote: > > > On Wed, 5 Mar 2008, Rafael J. Wysocki wrote: > > > > > > > -void device_pm_add(struct device *dev) > > > > +int device_pm_add(struct device *dev) > > > > { > > > > + int error = 0; > > > > + > > > > pr_debug("PM: Adding info for %s:%s\n", > > > > dev->bus ? dev->bus->name : "No Bus", > > > > kobject_name(&dev->kobj)); > > > > mutex_lock(&dpm_list_mtx); > > > > - list_add_tail(&dev->power.entry, &dpm_active); > > > > + if (dev->parent && dev->parent->power.sleeping) { > > > > + WARN_ON(true); > > > > > > I would prefer to put a dev_warn() line here, so that people reading > > > the kernel log can easily tell which device caused the problem and what > > > sort of problem it is. Something like this: > > > > > > dev_warn(dev, "device added while parent %s is asleep\n", > > > dev->parent->bus_id); > > > WARN_ON(true); > > > > Added. > > > > > > @@ -426,6 +406,12 @@ static int dpm_suspend(pm_message_t stat > > > > struct list_head *entry = dpm_active.prev; > > > > struct device *dev = to_device(entry); > > > > > > > > + if (dev->parent && dev->parent->power.sleeping) { > > > > + WARN_ON(true); > > > > + error = -EAGAIN; > > > > + break; > > > > > > Again, a dev_warn() would be appropriate. > > > > I chose just "WARN_ON(dev->parent && dev->parent->power.sleeping)", > > which is shorter. :-) > > > > I don't really expect it to appear and if it's reported, it'll be easy to > > figure out everything from the stack trace. > > Okay. > > > Revised patch below. > > It looks good. Let's hope it doesn't mess up ACPI too badly... :-) > > Acked-by: Alan Stern Thanks! Okay, I also have the appended patch on top of this one. :-) Rafael --- From: Rafael J. Wysocki Include dpm_sysfs_add() into device_pm_add(), in analogy with device_pm_remove(), and modify device_add() to call the latter after bus_add_device(), to avoid situations in which the PM core may attempt to suspend a device the registration of which has not been successful. Signed-off-by: Rafael J. Wysocki --- drivers/base/core.c | 15 +++++---------- drivers/base/power/main.c | 4 +++- 2 files changed, 8 insertions(+), 11 deletions(-) Index: linux-2.6/drivers/base/core.c =================================================================== --- linux-2.6.orig/drivers/base/core.c +++ linux-2.6/drivers/base/core.c @@ -812,17 +812,12 @@ int device_add(struct device *dev) error = device_add_attrs(dev); if (error) goto AttrsError; - error = dpm_sysfs_add(dev); - if (error) - goto PMError; - error = device_pm_add(dev); - if (error) { - dpm_sysfs_remove(dev); - goto PMError; - } error = bus_add_device(dev); if (error) goto BusError; + error = device_pm_add(dev); + if (error) + goto PMError; kobject_uevent(&dev->kobj, KOBJ_ADD); bus_attach_device(dev); if (parent) @@ -842,9 +837,9 @@ int device_add(struct device *dev) Done: put_device(dev); return error; - BusError: - device_pm_remove(dev); PMError: + bus_remove_device(dev); + BusError: if (dev->bus) blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_DEL_DEVICE, dev); 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 @@ -75,7 +75,9 @@ int device_pm_add(struct device *dev) WARN_ON(true); error = -EBUSY; } else { - list_add_tail(&dev->power.entry, &dpm_active); + error = dpm_sysfs_add(dev); + if (!error) + list_add_tail(&dev->power.entry, &dpm_active); } mutex_unlock(&dpm_list_mtx); return error; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/