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author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-06-13 13:10:36 +0300 |
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committer | Bjorn Helgaas <bhelgaas@google.com> | 2019-06-15 00:08:36 +0300 |
commit | 151f4e2bdc7a04020ae5c533896fb91a16e1f501 (patch) | |
tree | 20c8504f4fea46bf421107074f511fd51acf44fc /Documentation/power/interface.txt | |
parent | 9595aee2a389be5dfa9a0121a14e8fba70f17278 (diff) | |
download | linux-151f4e2bdc7a04020ae5c533896fb91a16e1f501.tar.xz |
docs: power: convert docs to ReST and rename to *.rst
Convert the PM documents to ReST, in order to allow them to
build with Sphinx.
The conversion is actually:
- add blank lines and indentation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Diffstat (limited to 'Documentation/power/interface.txt')
-rw-r--r-- | Documentation/power/interface.txt | 77 |
1 files changed, 0 insertions, 77 deletions
diff --git a/Documentation/power/interface.txt b/Documentation/power/interface.txt deleted file mode 100644 index 27df7f98668a..000000000000 --- a/Documentation/power/interface.txt +++ /dev/null @@ -1,77 +0,0 @@ -Power Management Interface for System Sleep - -Copyright (c) 2016 Intel Corp., Rafael J. Wysocki <rafael.j.wysocki@intel.com> - -The power management subsystem provides userspace with a unified sysfs interface -for system sleep regardless of the underlying system architecture or platform. -The interface is located in the /sys/power/ directory (assuming that sysfs is -mounted at /sys). - -/sys/power/state is the system sleep state control file. - -Reading from it returns a list of supported sleep states, encoded as: - -'freeze' (Suspend-to-Idle) -'standby' (Power-On Suspend) -'mem' (Suspend-to-RAM) -'disk' (Suspend-to-Disk) - -Suspend-to-Idle is always supported. Suspend-to-Disk is always supported -too as long the kernel has been configured to support hibernation at all -(ie. CONFIG_HIBERNATION is set in the kernel configuration file). Support -for Suspend-to-RAM and Power-On Suspend depends on the capabilities of the -platform. - -If one of the strings listed in /sys/power/state is written to it, the system -will attempt to transition into the corresponding sleep state. Refer to -Documentation/admin-guide/pm/sleep-states.rst for a description of each of -those states. - -/sys/power/disk controls the operating mode of hibernation (Suspend-to-Disk). -Specifically, it tells the kernel what to do after creating a hibernation image. - -Reading from it returns a list of supported options encoded as: - -'platform' (put the system into sleep using a platform-provided method) -'shutdown' (shut the system down) -'reboot' (reboot the system) -'suspend' (trigger a Suspend-to-RAM transition) -'test_resume' (resume-after-hibernation test mode) - -The currently selected option is printed in square brackets. - -The 'platform' option is only available if the platform provides a special -mechanism to put the system to sleep after creating a hibernation image (ACPI -does that, for example). The 'suspend' option is available if Suspend-to-RAM -is supported. Refer to Documentation/power/basic-pm-debugging.txt for the -description of the 'test_resume' option. - -To select an option, write the string representing it to /sys/power/disk. - -/sys/power/image_size controls the size of hibernation images. - -It can be written a string representing a non-negative integer that will be -used as a best-effort upper limit of the image size, in bytes. The hibernation -core will do its best to ensure that the image size will not exceed that number. -However, if that turns out to be impossible to achieve, a hibernation image will -still be created and its size will be as small as possible. In particular, -writing '0' to this file will enforce hibernation images to be as small as -possible. - -Reading from this file returns the current image size limit, which is set to -around 2/5 of available RAM by default. - -/sys/power/pm_trace controls the PM trace mechanism saving the last suspend -or resume event point in the RTC across reboots. - -It helps to debug hard lockups or reboots due to device driver failures that -occur during system suspend or resume (which is more common) more effectively. - -If /sys/power/pm_trace contains '1', the fingerprint of each suspend/resume -event point in turn will be stored in the RTC memory (overwriting the actual -RTC information), so it will survive a system crash if one occurs right after -storing it and it can be used later to identify the driver that caused the crash -to happen (see Documentation/power/s2ram.txt for more information). - -Initially it contains '0' which may be changed to '1' by writing a string -representing a nonzero integer into it. |