From patchwork Sat Jan 23 23:38:07 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rafael Wysocki X-Patchwork-Id: 74974 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.2) with ESMTP id o0NNjKln017213 for ; Sat, 23 Jan 2010 23:45:21 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753075Ab0AWXm0 (ORCPT ); Sat, 23 Jan 2010 18:42:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932131Ab0AWXmV (ORCPT ); Sat, 23 Jan 2010 18:42:21 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:43525 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753112Ab0AWXmD (ORCPT ); Sat, 23 Jan 2010 18:42:03 -0500 Received: from localhost (localhost.localdomain [127.0.0.1]) by ogre.sisk.pl (Postfix) with ESMTP id DF823174DC6; Sun, 24 Jan 2010 00:30:36 +0100 (CET) Received: from ogre.sisk.pl ([127.0.0.1]) by localhost (ogre.sisk.pl [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 04578-03; Sun, 24 Jan 2010 00:30:17 +0100 (CET) Received: from tosh.localnet (220-bem-13.acn.waw.pl [82.210.184.220]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ogre.sisk.pl (Postfix) with ESMTP id 7F00F174DDA; Sun, 24 Jan 2010 00:30:17 +0100 (CET) From: "Rafael J. Wysocki" To: LKML Subject: [PATCH 4/8] PM: Add facility for advanced testing of async suspend/resume Date: Sun, 24 Jan 2010 00:38:07 +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 Message-Id: <201001240038.07571.rjw@sisk.pl> X-Virus-Scanned: amavisd-new at ogre.sisk.pl using MkS_Vir for Linux Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Index: linux-2.6/drivers/base/power/sysfs.c =================================================================== --- linux-2.6.orig/drivers/base/power/sysfs.c +++ linux-2.6/drivers/base/power/sysfs.c @@ -54,6 +54,24 @@ * wakeup events internally (unless they are disabled), keeping * their hardware in low power modes whenever they're unused. This * saves runtime power, without requiring system-wide sleep states. + * + * async - Report/change current async suspend setting for the device + * + * Asynchronous suspend and resume of the device during system-wide power + * state transitions can be enabled by writing "enabled" to this file. + * Analogously, if "disabled" is written to this file, the device will be + * suspended and resumed synchronously. + * + * All devices have one of the following two values for power/async: + * + * + "enabled\n" to permit the asynchronous suspend/resume of the device; + * + "disabled\n" to forbid it; + * + * NOTE: It generally is unsafe to permit the asynchronous suspend/resume + * of a device unless it is certain that all of the PM dependencies of the + * device are known to the PM core. However, for some devices this + * attribute is set to "enabled" by bus type code or device drivers and in + * that cases it should be safe to leave the default value. */ static const char enabled[] = "enabled"; @@ -125,12 +143,43 @@ wake_store(struct device * dev, struct d static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store); +#ifdef CONFIG_PM_SLEEP_ADVANCED_DEBUG +static ssize_t async_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%s\n", + device_async_suspend_enabled(dev) ? enabled : disabled); +} + +static ssize_t async_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t n) +{ + char *cp; + int len = n; + + cp = memchr(buf, '\n', n); + if (cp) + len = cp - buf; + if (len == sizeof enabled - 1 && strncmp(buf, enabled, len) == 0) + device_enable_async_suspend(dev); + else if (len == sizeof disabled - 1 && strncmp(buf, disabled, len) == 0) + device_disable_async_suspend(dev); + else + return -EINVAL; + return n; +} + +static DEVICE_ATTR(async, 0644, async_show, async_store); +#endif /* CONFIG_PM_SLEEP_ADVANCED_DEBUG */ static struct attribute * power_attrs[] = { #ifdef CONFIG_PM_RUNTIME &dev_attr_control.attr, #endif &dev_attr_wakeup.attr, +#ifdef CONFIG_PM_SLEEP_ADVANCED_DEBUG + &dev_attr_async.attr, +#endif NULL, }; static struct attribute_group pm_attr_group = { Index: linux-2.6/include/linux/device.h =================================================================== --- linux-2.6.orig/include/linux/device.h +++ linux-2.6/include/linux/device.h @@ -478,6 +478,17 @@ static inline void device_enable_async_s dev->power.async_suspend = true; } +static inline void device_disable_async_suspend(struct device *dev) +{ + if (dev->power.status == DPM_ON) + dev->power.async_suspend = false; +} + +static inline bool device_async_suspend_enabled(struct device *dev) +{ + return !!dev->power.async_suspend; +} + void driver_init(void); /* Index: linux-2.6/kernel/power/Kconfig =================================================================== --- linux-2.6.orig/kernel/power/Kconfig +++ linux-2.6/kernel/power/Kconfig @@ -27,6 +27,15 @@ config PM_DEBUG code. This is helpful when debugging and reporting PM bugs, like suspend support. +config PM_ADVANCED_DEBUG + bool "Extra PM attributes in sysfs for low-level debugging/testing" + depends on PM_DEBUG + default n + ---help--- + Add extra sysfs attributes allowing one to access some Power Management + fields of device objects from user space. If you are not a kernel + developer interested in debugging/testing Power Management, say "no". + config PM_VERBOSE bool "Verbose Power Management debugging" depends on PM_DEBUG @@ -85,6 +94,11 @@ config PM_SLEEP depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE default y +config PM_SLEEP_ADVANCED_DEBUG + bool + depends on PM_ADVANCED_DEBUG + default n + config SUSPEND bool "Suspend to RAM and standby" depends on PM && ARCH_SUSPEND_POSSIBLE Index: linux-2.6/Documentation/ABI/testing/sysfs-devices-power =================================================================== --- linux-2.6.orig/Documentation/ABI/testing/sysfs-devices-power +++ linux-2.6/Documentation/ABI/testing/sysfs-devices-power @@ -51,3 +51,29 @@ Description: drivers. Changing this attribute to "on" prevents the driver from power managing the device at run time. Doing that while the device is suspended causes it to be woken up. + +What: /sys/devices/.../power/async +Date: January 2009 +Contact: Rafael J. Wysocki +Description: + The /sys/devices/.../async attribute allows the user space to + enable or diasble the device's suspend and resume callbacks to + be executed asynchronously (ie. in separate threads, in parallel + with the main suspend/resume thread) during system-wide power + transitions (eg. suspend to RAM, hibernation). + + All devices have one of the following two values for the + power/async file: + + + "enabled\n" to permit the asynchronous suspend/resume; + + "disabled\n" to forbid it; + + The value of this attribute may be changed by writing either + "enabled", or "disabled" to it. + + It generally is unsafe to permit the asynchronous suspend/resume + of a device unless it is certain that all of the PM dependencies + of the device are known to the PM core. However, for some + devices this attribute is set to "enabled" by bus type code or + device drivers and in that cases it should be safe to leave the + default value.