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Diffstat (limited to 'Documentation/ABI/testing/sysfs-power')
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diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power deleted file mode 100644 index 31725ffeeb3..00000000000 --- a/Documentation/ABI/testing/sysfs-power +++ /dev/null @@ -1,233 +0,0 @@ -What: /sys/power/ -Date: August 2006 -Contact: Rafael J. Wysocki <rjw@sisk.pl> -Description: - The /sys/power directory will contain files that will - provide a unified interface to the power management - subsystem. - -What: /sys/power/state -Date: August 2006 -Contact: Rafael J. Wysocki <rjw@sisk.pl> -Description: - The /sys/power/state file controls the system power state. - Reading from this file returns what states are supported, - which is hard-coded to 'standby' (Power-On Suspend), 'mem' - (Suspend-to-RAM), and 'disk' (Suspend-to-Disk). - - Writing to this file one of these strings causes the system to - transition into that state. Please see the file - Documentation/power/states.txt for a description of each of - these states. - -What: /sys/power/disk -Date: September 2006 -Contact: Rafael J. Wysocki <rjw@sisk.pl> -Description: - The /sys/power/disk file controls the operating mode of the - suspend-to-disk mechanism. Reading from this file returns - the name of the method by which the system will be put to - sleep on the next suspend. There are four methods supported: - 'firmware' - means that the memory image will be saved to disk - by some firmware, in which case we also assume that the - firmware will handle the system suspend. - 'platform' - the memory image will be saved by the kernel and - the system will be put to sleep by the platform driver (e.g. - ACPI or other PM registers). - 'shutdown' - the memory image will be saved by the kernel and - the system will be powered off. - 'reboot' - the memory image will be saved by the kernel and - the system will be rebooted. - - Additionally, /sys/power/disk can be used to turn on one of the - two testing modes of the suspend-to-disk mechanism: 'testproc' - or 'test'. If the suspend-to-disk mechanism is in the - 'testproc' mode, writing 'disk' to /sys/power/state will cause - the kernel to disable nonboot CPUs and freeze tasks, wait for 5 - seconds, unfreeze tasks and enable nonboot CPUs. If it is in - the 'test' mode, writing 'disk' to /sys/power/state will cause - the kernel to disable nonboot CPUs and freeze tasks, shrink - memory, suspend devices, wait for 5 seconds, resume devices, - unfreeze tasks and enable nonboot CPUs. Then, we are able to - look in the log messages and work out, for example, which code - is being slow and which device drivers are misbehaving. - - The suspend-to-disk method may be chosen by writing to this - file one of the accepted strings: - - 'firmware' - 'platform' - 'shutdown' - 'reboot' - 'testproc' - 'test' - - It will only change to 'firmware' or 'platform' if the system - supports that. - -What: /sys/power/image_size -Date: August 2006 -Contact: Rafael J. Wysocki <rjw@sisk.pl> -Description: - The /sys/power/image_size file controls the size of the image - created by the suspend-to-disk mechanism. It can be written a - string representing a non-negative integer that will be used - as an upper limit of the image size, in bytes. The kernel's - suspend-to-disk code will do its best to ensure the image size - will not exceed this number. However, if it turns out to be - impossible, the kernel will try to suspend anyway using the - smallest image possible. In particular, if "0" is written to - this file, the suspend image will be as small as possible. - - Reading from this file will display the current image size - limit, which is set to 500 MB by default. - -What: /sys/power/pm_trace -Date: August 2006 -Contact: Rafael J. Wysocki <rjw@sisk.pl> -Description: - The /sys/power/pm_trace file controls the code which saves the - last PM event point in the RTC across reboots, so that you can - debug a machine that just hangs during suspend (or more - commonly, during resume). Namely, the RTC is only used to save - the last PM event point if this file contains '1'. Initially - it contains '0' which may be changed to '1' by writing a - string representing a nonzero integer into it. - - To use this debugging feature you should attempt to suspend - the machine, then reboot it and run - - dmesg -s 1000000 | grep 'hash matches' - - If you do not get any matches (or they appear to be false - positives), it is possible that the last PM event point - referred to a device created by a loadable kernel module. In - this case cat /sys/power/pm_trace_dev_match (see below) after - your system is started up and the kernel modules are loaded. - - 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_trace_dev_match -Date: October 2010 -Contact: James Hogan <james@albanarts.com> -Description: - The /sys/power/pm_trace_dev_match file contains the name of the - device associated with the last PM event point saved in the RTC - across reboots when pm_trace has been used. More precisely it - contains the list of current devices (including those - registered by loadable kernel modules since boot) which match - the device hash in the RTC at boot, with a newline after each - one. - - The advantage of this file over the hash matches printed to the - kernel log (see /sys/power/pm_trace), is that it includes - devices created after boot by loadable kernel modules. - - Due to the small hash size necessary to fit in the RTC, it is - possible that more than one device matches the hash, in which - case further investigation is required to determine which - device is causing the problem. Note that genuine RTC clock - values (such as when pm_trace has not been used), can still - match a device and output it's name here. - -What: /sys/power/pm_async -Date: January 2009 -Contact: Rafael J. Wysocki <rjw@sisk.pl> -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. - -What: /sys/power/wakeup_count -Date: July 2010 -Contact: Rafael J. Wysocki <rjw@sisk.pl> -Description: - The /sys/power/wakeup_count file allows user space to put the - system into a sleep state while taking into account the - concurrent arrival of wakeup events. Reading from it returns - the current number of registered wakeup events and it blocks if - some wakeup events are being processed at the time the file is - read from. Writing to it will only succeed if the current - number of wakeup events is equal to the written value and, if - successful, will make the kernel abort a subsequent transition - to a sleep state if any wakeup events are reported after the - write has returned. - -What: /sys/power/reserved_size -Date: May 2011 -Contact: Rafael J. Wysocki <rjw@sisk.pl> -Description: - The /sys/power/reserved_size file allows user space to control - the amount of memory reserved for allocations made by device - drivers during the "device freeze" stage of hibernation. It can - be written a string representing a non-negative integer that - will be used as the amount of memory to reserve for allocations - made by device drivers' "freeze" callbacks, in bytes. - - Reading from this file will display the current value, which is - set to 1 MB by default. - -What: /sys/power/autosleep -Date: April 2012 -Contact: Rafael J. Wysocki <rjw@sisk.pl> -Description: - The /sys/power/autosleep file can be written one of the strings - returned by reads from /sys/power/state. If that happens, a - work item attempting to trigger a transition of the system to - the sleep state represented by that string is queued up. This - attempt will only succeed if there are no active wakeup sources - in the system at that time. After every execution, regardless - of whether or not the attempt to put the system to sleep has - succeeded, the work item requeues itself until user space - writes "off" to /sys/power/autosleep. - - Reading from this file causes the last string successfully - written to it to be returned. - -What: /sys/power/wake_lock -Date: February 2012 -Contact: Rafael J. Wysocki <rjw@sisk.pl> -Description: - The /sys/power/wake_lock file allows user space to create - wakeup source objects and activate them on demand (if one of - those wakeup sources is active, reads from the - /sys/power/wakeup_count file block or return false). When a - string without white space is written to /sys/power/wake_lock, - it will be assumed to represent a wakeup source name. If there - is a wakeup source object with that name, it will be activated - (unless active already). Otherwise, a new wakeup source object - will be registered, assigned the given name and activated. - If a string written to /sys/power/wake_lock contains white - space, the part of the string preceding the white space will be - regarded as a wakeup source name and handled as descrived above. - The other part of the string will be regarded as a timeout (in - nanoseconds) such that the wakeup source will be automatically - deactivated after it has expired. The timeout, if present, is - set regardless of the current state of the wakeup source object - in question. - - Reads from this file return a string consisting of the names of - wakeup sources created with the help of it that are active at - the moment, separated with spaces. - - -What: /sys/power/wake_unlock -Date: February 2012 -Contact: Rafael J. Wysocki <rjw@sisk.pl> -Description: - The /sys/power/wake_unlock file allows user space to deactivate - wakeup sources created with the help of /sys/power/wake_lock. - When a string is written to /sys/power/wake_unlock, it will be - assumed to represent the name of a wakeup source to deactivate. - If a wakeup source object of that name exists and is active at - the moment, it will be deactivated. - - Reads from this file return a string consisting of the names of - wakeup sources created with the help of /sys/power/wake_lock - that are inactive at the moment, separated with spaces. |