From 6cbf82148ff286ec22a55be6836c3a5bffc489c1 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 17 Feb 2010 23:44:58 +0100 Subject: PCI PM: Run-time callbacks for PCI bus type Introduce run-time PM callbacks for the PCI bus type. Make the new callbacks work in analogy with the existing system sleep PM callbacks, so that the drivers already converted to struct dev_pm_ops can use their suspend and resume routines for run-time PM without modifications. Signed-off-by: Rafael J. Wysocki Signed-off-by: Jesse Barnes --- kernel/power/Kconfig | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel/power/Kconfig') diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 91e09d3b2eb2..4c9cffcf69c7 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -222,3 +222,8 @@ config PM_RUNTIME and the bus type drivers of the buses the devices are on are responsible for the actual handling of the autosuspend requests and wake-up events. + +config PM_OPS + bool + depends on PM_SLEEP || PM_RUNTIME + default y -- cgit From 5a2eb8585f3b38e01e30aacaa8b985a1520a993d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 23 Jan 2010 22:25:23 +0100 Subject: PM: Add facility for advanced testing of async suspend/resume Add configuration switch CONFIG_PM_ADVANCED_DEBUG for compiling in extra PM debugging/testing code allowing one to access some PM-related attributes of devices from the user space via sysfs. If CONFIG_PM_ADVANCED_DEBUG is set, add sysfs attribute power/async for every device allowing the user space to access the device's power.async_suspend flag and modify it, if desired. Signed-off-by: Rafael J. Wysocki --- Documentation/ABI/testing/sysfs-devices-power | 26 ++++++++++++++ drivers/base/power/sysfs.c | 49 +++++++++++++++++++++++++++ include/linux/device.h | 11 ++++++ kernel/power/Kconfig | 14 ++++++++ 4 files changed, 100 insertions(+) (limited to 'kernel/power/Kconfig') diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power index 431bfd7e65c7..6123c523bfd7 100644 --- a/Documentation/ABI/testing/sysfs-devices-power +++ b/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. diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c index c011ff15632c..86fd9373447e 100644 --- a/drivers/base/power/sysfs.c +++ b/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 device_attribute *attr, 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 = { diff --git a/include/linux/device.h b/include/linux/device.h index 70adc5f3f50a..b30527db3ac0 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -478,6 +478,17 @@ static inline void device_enable_async_suspend(struct device *dev) 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); /* diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 4c9cffcf69c7..5c36ea9d55d2 100644 --- a/kernel/power/Kconfig +++ b/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 -- cgit