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Diffstat (limited to 'Documentation/ABI/testing/sysfs-power')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-power | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index 64c9276e9421..f4551816329e 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/Documentation/ABI/testing/sysfs-power @@ -7,19 +7,30 @@ Description: subsystem. What: /sys/power/state -Date: August 2006 +Date: May 2014 Contact: Rafael J. Wysocki <rjw@rjwysocki.net> 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 'freeze' (Low-Power Idle), 'standby' - (Power-On Suspend), 'mem' (Suspend-to-RAM), and 'disk' - (Suspend-to-Disk). + The /sys/power/state file controls system sleep states. + Reading from this file returns the available sleep state + labels, which may be "mem", "standby", "freeze" and "disk" + (hibernation). The meanings of the first three labels depend on + the relative_sleep_states command line argument as follows: + 1) relative_sleep_states = 1 + "mem", "standby", "freeze" represent non-hibernation sleep + states from the deepest ("mem", always present) to the + shallowest ("freeze"). "standby" and "freeze" may or may + not be present depending on the capabilities of the + platform. "freeze" can only be present if "standby" is + present. + 2) relative_sleep_states = 0 (default) + "mem" - "suspend-to-RAM", present if supported. + "standby" - "power-on suspend", present if supported. + "freeze" - "suspend-to-idle", always present. 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. + transition into the corresponding state, if available. See + Documentation/power/states.txt for a description of what + "suspend-to-RAM", "power-on suspend" and "suspend-to-idle" mean. What: /sys/power/disk Date: September 2006 |