Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753707Ab0AWXmp (ORCPT ); Sat, 23 Jan 2010 18:42:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753306Ab0AWXmN (ORCPT ); Sat, 23 Jan 2010 18:42:13 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:43515 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753078Ab0AWXmC (ORCPT ); Sat, 23 Jan 2010 18:42:02 -0500 From: "Rafael J. Wysocki" To: LKML Subject: [PATCH 3/8] PM: Add a switch for disabling/enabling asynchronous suspend/resume Date: Sun, 24 Jan 2010 00:36:26 +0100 User-Agent: KMail/1.12.3 (Linux/2.6.33-rc4-rjw; KDE/4.3.3; x86_64; ; ) Cc: Alan Stern , Linus Torvalds , Linux PCI , pm list , linux-usb@vger.kernel.org, Greg KH , Jesse Barnes , James Bottomley , Linux SCSI , Arjan van de Ven , ACPI Devel Maling List , Len Brown , Nigel Cunningham References: <201001240033.34253.rjw@sisk.pl> In-Reply-To: <201001240033.34253.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201001240036.27069.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4516 Lines: 141 From: Rafael J. Wysocki Add sysfs attribute /sys/power/pm_async allowing the user space to disable/enable asynchronous suspend/resume of devices. Signed-off-by: Rafael J. Wysocki --- Documentation/ABI/testing/sysfs-power | 13 +++++++++++++ drivers/base/power/main.c | 7 ++++--- drivers/base/power/power.h | 6 +++--- kernel/power/main.c | 31 ++++++++++++++++++++++++++++++- 4 files changed, 50 insertions(+), 7 deletions(-) Index: linux-2.6/kernel/power/main.c =================================================================== --- linux-2.6.orig/kernel/power/main.c +++ linux-2.6/kernel/power/main.c @@ -44,6 +44,32 @@ int pm_notifier_call_chain(unsigned long == NOTIFY_BAD) ? -EINVAL : 0; } +/* If set, devices may be suspended and resumed asynchronously. */ +int pm_async_enabled = 1; + +static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", pm_async_enabled); +} + +static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr, + const char *buf, size_t n) +{ + unsigned long val; + + if (strict_strtoul(buf, 10, &val)) + return -EINVAL; + + if (val > 1) + return -EINVAL; + + pm_async_enabled = val; + return n; +} + +power_attr(pm_async); + #ifdef CONFIG_PM_DEBUG int pm_test_level = TEST_NONE; @@ -208,9 +234,12 @@ static struct attribute * g[] = { #ifdef CONFIG_PM_TRACE &pm_trace_attr.attr, #endif -#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG) +#ifdef CONFIG_PM_SLEEP + &pm_async_attr.attr, +#ifdef CONFIG_PM_DEBUG &pm_test_attr.attr, #endif +#endif NULL, }; 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 @@ -12,10 +12,10 @@ static inline void pm_runtime_remove(str #ifdef CONFIG_PM_SLEEP -/* - * main.c - */ +/* kernel/power/main.c */ +extern int pm_async_enabled; +/* drivers/base/power/main.c */ extern struct list_head dpm_list; /* The active device list */ static inline struct device *to_device(struct list_head *entry) 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 @@ -201,7 +201,7 @@ static void dpm_wait(struct device *dev, if (!dev) return; - if (async || dev->power.async_suspend) + if (async || (pm_async_enabled && dev->power.async_suspend)) wait_for_completion(&dev->power.completion); } @@ -563,7 +563,8 @@ static int device_resume(struct device * { INIT_COMPLETION(dev->power.completion); - if (dev->power.async_suspend && !pm_trace_is_enabled()) { + if (pm_async_enabled && dev->power.async_suspend + && !pm_trace_is_enabled()) { get_device(dev); async_schedule(async_resume, dev); return 0; @@ -867,7 +868,7 @@ static int device_suspend(struct device { INIT_COMPLETION(dev->power.completion); - if (dev->power.async_suspend) { + if (pm_async_enabled && dev->power.async_suspend) { get_device(dev); async_schedule(async_suspend, dev); return 0; Index: linux-2.6/Documentation/ABI/testing/sysfs-power =================================================================== --- linux-2.6.orig/Documentation/ABI/testing/sysfs-power +++ linux-2.6/Documentation/ABI/testing/sysfs-power @@ -101,3 +101,16 @@ Description: CAUTION: Using it will cause your machine's real-time (CMOS) clock to be set to a random invalid time after a resume. + +What: /sys/power/pm_async +Date: January 2009 +Contact: Rafael J. Wysocki +Description: + The /sys/power/pm_async file controls the switch allowing the + user space to enable or disable asynchronous suspend and resume + of devices. If enabled, this feature will cause some device + drivers' suspend and resume callbacks to be executed in parallel + with each other and with the main suspend thread. It is enabled + if this file contains "1", which is the default. It may be + disabled by writing "0" to this file, in which case all devices + will be suspended and resumed synchronously. -- 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/