From 971cb7fba0c84dd74c39020f4596b08398f58199 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 23 Jan 2010 22:03:22 +0100 Subject: PM: Document device power attributes in sysfs There are sysfs attributes in /sys/devices/.../power/ that haven't been documented yet in Documentation/ABI/. Document them as appropriate. Signed-off-by: Rafael J. Wysocki --- Documentation/ABI/testing/sysfs-devices-power | 53 +++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-devices-power (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power new file mode 100644 index 000000000000..431bfd7e65c7 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-power @@ -0,0 +1,53 @@ +What: /sys/devices/.../power/ +Date: January 2009 +Contact: Rafael J. Wysocki +Description: + The /sys/devices/.../power directory contains attributes + allowing the user space to check and modify some power + management related properties of given device. + +What: /sys/devices/.../power/wakeup +Date: January 2009 +Contact: Rafael J. Wysocki +Description: + The /sys/devices/.../power/wakeup attribute allows the user + space to check if the device is enabled to wake up the system + from sleep states, such as the memory sleep state (suspend to + RAM) and hibernation (suspend to disk), and to enable or disable + it to do that as desired. + + Some devices support "wakeup" events, which are hardware signals + used to activate the system from a sleep state. Such devices + have one of the following two values for the sysfs power/wakeup + file: + + + "enabled\n" to issue the events; + + "disabled\n" not to do so; + + In that cases the user space can change the setting represented + by the contents of this file by writing either "enabled", or + "disabled" to it. + + For the devices that are not capable of generating system wakeup + events this file contains "\n". In that cases the user space + cannot modify the contents of this file and the device cannot be + enabled to wake up the system. + +What: /sys/devices/.../power/control +Date: January 2009 +Contact: Rafael J. Wysocki +Description: + The /sys/devices/.../power/control attribute allows the user + space to control the run-time power management of the device. + + All devices have one of the following two values for the + power/control file: + + + "auto\n" to allow the device to be power managed at run time; + + "on\n" to prevent the device from being power managed; + + The default for all devices is "auto", which means that they may + be subject to automatic power management, depending on their + 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. -- cgit v1.2.3-70-g09d2 From 0e06b4a891c6a108412fe24b4500f499da2cf8a1 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 23 Jan 2010 22:25:15 +0100 Subject: PM: Add a switch for disabling/enabling asynchronous suspend/resume 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(-) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index dcff4d0623ad..d6a801f45b48 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/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. diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 3b44c201ddad..7e79201b09bb 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -201,7 +201,7 @@ static void dpm_wait(struct device *dev, bool async) 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 *dev) { 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 *dev) { 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; diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h index b8fa1aa5225a..c0bd03c83b9c 100644 --- a/drivers/base/power/power.h +++ b/drivers/base/power/power.h @@ -12,10 +12,10 @@ static inline void pm_runtime_remove(struct device *dev) {} #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) diff --git a/kernel/power/main.c b/kernel/power/main.c index 0998c7139053..b58800b21fc0 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -44,6 +44,32 @@ int pm_notifier_call_chain(unsigned long val) == 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; @@ -208,8 +234,11 @@ 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, }; -- cgit v1.2.3-70-g09d2 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 'Documentation') 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 v1.2.3-70-g09d2 From b694e52ebdd439e4591d4a6651658026196174f6 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Wed, 27 Jan 2010 23:47:50 +0100 Subject: PM / Hibernate: Really deprecate deprecated user ioctls They were deprecated and removed from exported headers more than 2 years ago. Inform users about their removal in the future now. (Switch cases needed to be reorderded for an easy fall through.) And add an entry to feature-removal-schedule. Signed-off-by: Jiri Slaby Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki --- Documentation/feature-removal-schedule.txt | 11 +++++++++++ kernel/power/user.c | 23 +++++++++++++++++++---- 2 files changed, 30 insertions(+), 4 deletions(-) (limited to 'Documentation') diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 0a46833c1b76..b9eba900e0f0 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -64,6 +64,17 @@ Who: Robin Getz & Matt Mackall --------------------------- +What: Deprecated snapshot ioctls +When: 2.6.36 + +Why: The ioctls in kernel/power/user.c were marked as deprecated long time + ago. Now they notify users about that so that they need to replace + their userspace. After some more time, remove them completely. + +Who: Jiri Slaby + +--------------------------- + What: The ieee80211_regdom module parameter When: March 2010 / desktop catchup diff --git a/kernel/power/user.c b/kernel/power/user.c index bf0014d6a5f0..4d2289626a84 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -195,6 +195,15 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf, return res; } +static void snapshot_deprecated_ioctl(unsigned int cmd) +{ + if (printk_ratelimit()) + printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will " + "be removed soon, update your suspend-to-disk " + "utilities\n", + __builtin_return_address(0), cmd); +} + static long snapshot_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { @@ -246,8 +255,9 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, data->frozen = 0; break; - case SNAPSHOT_CREATE_IMAGE: case SNAPSHOT_ATOMIC_SNAPSHOT: + snapshot_deprecated_ioctl(cmd); + case SNAPSHOT_CREATE_IMAGE: if (data->mode != O_RDONLY || !data->frozen || data->ready) { error = -EPERM; break; @@ -275,8 +285,9 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, data->ready = 0; break; - case SNAPSHOT_PREF_IMAGE_SIZE: case SNAPSHOT_SET_IMAGE_SIZE: + snapshot_deprecated_ioctl(cmd); + case SNAPSHOT_PREF_IMAGE_SIZE: image_size = arg; break; @@ -290,15 +301,17 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, error = put_user(size, (loff_t __user *)arg); break; - case SNAPSHOT_AVAIL_SWAP_SIZE: case SNAPSHOT_AVAIL_SWAP: + snapshot_deprecated_ioctl(cmd); + case SNAPSHOT_AVAIL_SWAP_SIZE: size = count_swap_pages(data->swap, 1); size <<= PAGE_SHIFT; error = put_user(size, (loff_t __user *)arg); break; - case SNAPSHOT_ALLOC_SWAP_PAGE: case SNAPSHOT_GET_SWAP_PAGE: + snapshot_deprecated_ioctl(cmd); + case SNAPSHOT_ALLOC_SWAP_PAGE: if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { error = -ENODEV; break; @@ -321,6 +334,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, break; case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */ + snapshot_deprecated_ioctl(cmd); if (!swsusp_swap_in_use()) { /* * User space encodes device types as two-byte values, @@ -362,6 +376,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, break; case SNAPSHOT_PMOPS: /* This ioctl is deprecated */ + snapshot_deprecated_ioctl(cmd); error = -EINVAL; switch (arg) { -- cgit v1.2.3-70-g09d2