diff options
Diffstat (limited to 'Documentation/power')
| -rw-r--r-- | Documentation/power/00-INDEX | 2 | ||||
| -rw-r--r-- | Documentation/power/devices.txt | 14 | ||||
| -rw-r--r-- | Documentation/power/pci.txt | 10 | ||||
| -rw-r--r-- | Documentation/power/runtime_pm.txt | 2 | ||||
| -rw-r--r-- | Documentation/power/states.txt | 60 | ||||
| -rw-r--r-- | Documentation/power/swsusp-dmcrypt.txt | 2 |
6 files changed, 59 insertions, 31 deletions
diff --git a/Documentation/power/00-INDEX b/Documentation/power/00-INDEX index ad04cc8097ed..7cb6085839f3 100644 --- a/Documentation/power/00-INDEX +++ b/Documentation/power/00-INDEX @@ -6,7 +6,7 @@ basic-pm-debugging.txt - Debugging suspend and resume charger-manager.txt - Battery charger management. -devices.txt +admin-guide/devices.rst - How drivers interact with system-wide power management drivers-testing.txt - Testing suspend and resume support in device drivers diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index 8ba6625fdd63..73ddea39a9ce 100644 --- a/Documentation/power/devices.txt +++ b/Documentation/power/devices.txt @@ -607,7 +607,9 @@ individually. Instead, a set of devices sharing a power resource can be put into a low-power state together at the same time by turning off the shared power resource. Of course, they also need to be put into the full-power state together, by turning the shared power resource on. A set of devices with this -property is often referred to as a power domain. +property is often referred to as a power domain. A power domain may also be +nested inside another power domain. The nested domain is referred to as the +sub-domain of the parent domain. Support for power domains is provided through the pm_domain field of struct device. This field is a pointer to an object of type struct dev_pm_domain, @@ -629,6 +631,16 @@ support for power domains into subsystem-level callbacks, for example by modifying the platform bus type. Other platforms need not implement it or take it into account in any way. +Devices may be defined as IRQ-safe which indicates to the PM core that their +runtime PM callbacks may be invoked with disabled interrupts (see +Documentation/power/runtime_pm.txt for more information). If an IRQ-safe +device belongs to a PM domain, the runtime PM of the domain will be +disallowed, unless the domain itself is defined as IRQ-safe. However, it +makes sense to define a PM domain as IRQ-safe only if all the devices in it +are IRQ-safe. Moreover, if an IRQ-safe domain has a parent domain, the runtime +PM of the parent is only allowed if the parent itself is IRQ-safe too with the +additional restriction that all child domains of an IRQ-safe parent must also +be IRQ-safe. Device Low Power (suspend) States --------------------------------- diff --git a/Documentation/power/pci.txt b/Documentation/power/pci.txt index 44558882aa60..85c746cbab2c 100644 --- a/Documentation/power/pci.txt +++ b/Documentation/power/pci.txt @@ -8,7 +8,7 @@ management. Based on previous work by Patrick Mochel <mochel@transmeta.com> This document only covers the aspects of power management specific to PCI devices. For general description of the kernel's interfaces related to device -power management refer to Documentation/power/devices.txt and +power management refer to Documentation/power/admin-guide/devices.rst and Documentation/power/runtime_pm.txt. --------------------------------------------------------------------------- @@ -417,7 +417,7 @@ pm->runtime_idle() callback. 2.4. System-Wide Power Transitions ---------------------------------- There are a few different types of system-wide power transitions, described in -Documentation/power/devices.txt. Each of them requires devices to be handled +Documentation/power/admin-guide/devices.rst. Each of them requires devices to be handled in a specific way and the PM core executes subsystem-level power management callbacks for this purpose. They are executed in phases such that each phase involves executing the same subsystem-level callback for every device belonging @@ -623,7 +623,7 @@ System restore requires a hibernation image to be loaded into memory and the pre-hibernation memory contents to be restored before the pre-hibernation system activity can be resumed. -As described in Documentation/power/devices.txt, the hibernation image is loaded +As described in Documentation/power/admin-guide/devices.rst, the hibernation image is loaded into memory by a fresh instance of the kernel, called the boot kernel, which in turn is loaded and run by a boot loader in the usual way. After the boot kernel has loaded the image, it needs to replace its own code and data with the code @@ -677,7 +677,7 @@ controlling the runtime power management of their devices. At the time of this writing there are two ways to define power management callbacks for a PCI device driver, the recommended one, based on using a -dev_pm_ops structure described in Documentation/power/devices.txt, and the +dev_pm_ops structure described in Documentation/power/admin-guide/devices.rst, and the "legacy" one, in which the .suspend(), .suspend_late(), .resume_early(), and .resume() callbacks from struct pci_driver are used. The legacy approach, however, doesn't allow one to define runtime power management callbacks and is @@ -1046,5 +1046,5 @@ PCI Local Bus Specification, Rev. 3.0 PCI Bus Power Management Interface Specification, Rev. 1.2 Advanced Configuration and Power Interface (ACPI) Specification, Rev. 3.0b PCI Express Base Specification, Rev. 2.0 -Documentation/power/devices.txt +Documentation/power/admin-guide/devices.rst Documentation/power/runtime_pm.txt diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt index 1fd1fbe9ce95..4870980e967e 100644 --- a/Documentation/power/runtime_pm.txt +++ b/Documentation/power/runtime_pm.txt @@ -674,7 +674,7 @@ left in runtime suspend. If that happens, the PM core will not execute any system suspend and resume callbacks for all of those devices, except for the complete callback, which is then entirely responsible for handling the device as appropriate. This only applies to system suspend transitions that are not -related to hibernation (see Documentation/power/devices.txt for more +related to hibernation (see Documentation/power/admin-guide/devices.rst for more information). The PM core does its best to reduce the probability of race conditions between diff --git a/Documentation/power/states.txt b/Documentation/power/states.txt index 50f3ef9177c1..008ecb588317 100644 --- a/Documentation/power/states.txt +++ b/Documentation/power/states.txt @@ -8,25 +8,41 @@ for each state. The states are represented by strings that can be read or written to the /sys/power/state file. Those strings may be "mem", "standby", "freeze" and -"disk", where the last one always represents hibernation (Suspend-To-Disk) and -the meaning of the remaining ones depends on the relative_sleep_states command -line argument. - -For relative_sleep_states=1, the strings "mem", "standby" and "freeze" label the -available non-hibernation sleep states from the deepest to the shallowest, -respectively. In that case, "mem" is always present in /sys/power/state, -because there is at least one non-hibernation sleep state in every system. If -the given system supports two non-hibernation sleep states, "standby" is present -in /sys/power/state in addition to "mem". If the system supports three -non-hibernation sleep states, "freeze" will be present in /sys/power/state in -addition to "mem" and "standby". - -For relative_sleep_states=0, which is the default, the following descriptions -apply. - -state: Suspend-To-Idle +"disk", where the last three always represent Power-On Suspend (if supported), +Suspend-To-Idle and hibernation (Suspend-To-Disk), respectively. + +The meaning of the "mem" string is controlled by the /sys/power/mem_sleep file. +It contains strings representing the available modes of system suspend that may +be triggered by writing "mem" to /sys/power/state. These modes are "s2idle" +(Suspend-To-Idle), "shallow" (Power-On Suspend) and "deep" (Suspend-To-RAM). +The "s2idle" mode is always available, while the other ones are only available +if supported by the platform (if not supported, the strings representing them +are not present in /sys/power/mem_sleep). The string representing the suspend +mode to be used subsequently is enclosed in square brackets. Writing one of +the other strings present in /sys/power/mem_sleep to it causes the suspend mode +to be used subsequently to change to the one represented by that string. + +Consequently, there are two ways to cause the system to go into the +Suspend-To-Idle sleep state. The first one is to write "freeze" directly to +/sys/power/state. The second one is to write "s2idle" to /sys/power/mem_sleep +and then to wrtie "mem" to /sys/power/state. Similarly, there are two ways +to cause the system to go into the Power-On Suspend sleep state (the strings to +write to the control files in that case are "standby" or "shallow" and "mem", +respectively) if that state is supported by the platform. In turn, there is +only one way to cause the system to go into the Suspend-To-RAM state (write +"deep" into /sys/power/mem_sleep and "mem" into /sys/power/state). + +The default suspend mode (ie. the one to be used without writing anything into +/sys/power/mem_sleep) is either "deep" (if Suspend-To-RAM is supported) or +"s2idle", but it can be overridden by the value of the "mem_sleep_default" +parameter in the kernel command line. + +The properties of all of the sleep states are described below. + + +State: Suspend-To-Idle ACPI state: S0 -Label: "freeze" +Label: "s2idle" ("freeze") This state is a generic, pure software, light-weight, system sleep state. It allows more energy to be saved relative to runtime idle by freezing user @@ -35,13 +51,13 @@ lower-power than available at run time), such that the processors can spend more time in their idle states. This state can be used for platforms without Power-On Suspend/Suspend-to-RAM -support, or it can be used in addition to Suspend-to-RAM (memory sleep) -to provide reduced resume latency. It is always supported. +support, or it can be used in addition to Suspend-to-RAM to provide reduced +resume latency. It is always supported. State: Standby / Power-On Suspend ACPI State: S1 -Label: "standby" +Label: "shallow" ("standby") This state, if supported, offers moderate, though real, power savings, while providing a relatively low-latency transition back to a working system. No @@ -58,7 +74,7 @@ state. State: Suspend-to-RAM ACPI State: S3 -Label: "mem" +Label: "deep" This state, if supported, offers significant power savings as everything in the system is put into a low-power state, except for memory, which should be placed diff --git a/Documentation/power/swsusp-dmcrypt.txt b/Documentation/power/swsusp-dmcrypt.txt index 59931b46ff7e..b802fbfd95ef 100644 --- a/Documentation/power/swsusp-dmcrypt.txt +++ b/Documentation/power/swsusp-dmcrypt.txt @@ -8,7 +8,7 @@ Some prerequisites: You know how dm-crypt works. If not, visit the following web page: http://www.saout.de/misc/dm-crypt/ You have read Documentation/power/swsusp.txt and understand it. -You did read Documentation/initrd.txt and know how an initrd works. +You did read Documentation/admin-guide/initrd.rst and know how an initrd works. You know how to create or how to modify an initrd. Now your system is properly set up, your disk is encrypted except for |