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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-11-06 13:54:47 +0100 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-11-06 13:54:47 +0100 |
commit | 69a10ca747c2d2d7c0354a883335e097c067ed35 (patch) | |
tree | a8b1f56f95af55a4d9bd826b7e5e6d31b8cd6b98 /Documentation | |
parent | 96428e98aebe5db8a164711f102808651c7f518d (diff) | |
parent | a192aa923b66a435aae56983c4912ee150bc9b32 (diff) | |
download | linux-stable-69a10ca747c2d2d7c0354a883335e097c067ed35.tar.gz linux-stable-69a10ca747c2d2d7c0354a883335e097c067ed35.tar.bz2 linux-stable-69a10ca747c2d2d7c0354a883335e097c067ed35.zip |
Merge branch 'acpi-pm' into pm-core
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/ABI/testing/sysfs-devices-power | 16 | ||||
-rw-r--r-- | Documentation/acpi/lpit.txt | 25 | ||||
-rw-r--r-- | Documentation/power/pm_qos_interface.txt | 13 |
3 files changed, 31 insertions, 23 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power index 676fdf5f2a99..f4b24c327665 100644 --- a/Documentation/ABI/testing/sysfs-devices-power +++ b/Documentation/ABI/testing/sysfs-devices-power @@ -258,19 +258,3 @@ Description: This attribute has no effect on system-wide suspend/resume and hibernation. - -What: /sys/devices/.../power/pm_qos_remote_wakeup -Date: September 2012 -Contact: Rafael J. Wysocki <rjw@rjwysocki.net> -Description: - The /sys/devices/.../power/pm_qos_remote_wakeup attribute - is used for manipulating the PM QoS "remote wakeup required" - flag. If set, this flag indicates to the kernel that the - device is a source of user events that have to be signaled from - its low-power states. - - Not all drivers support this attribute. If it isn't supported, - it is not present. - - This attribute has no effect on system-wide suspend/resume and - hibernation. diff --git a/Documentation/acpi/lpit.txt b/Documentation/acpi/lpit.txt new file mode 100644 index 000000000000..b426398d2e97 --- /dev/null +++ b/Documentation/acpi/lpit.txt @@ -0,0 +1,25 @@ +To enumerate platform Low Power Idle states, Intel platforms are using +“Low Power Idle Table” (LPIT). More details about this table can be +downloaded from: +http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf + +Residencies for each low power state can be read via FFH +(Function fixed hardware) or a memory mapped interface. + +On platforms supporting S0ix sleep states, there can be two types of +residencies: +- CPU PKG C10 (Read via FFH interface) +- Platform Controller Hub (PCH) SLP_S0 (Read via memory mapped interface) + +The following attributes are added dynamically to the cpuidle +sysfs attribute group: + /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us + /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us + +The "low_power_idle_cpu_residency_us" attribute shows time spent +by the CPU package in PKG C10 + +The "low_power_idle_system_residency_us" attribute shows SLP_S0 +residency, or system time spent with the SLP_S0# signal asserted. +This is the lowest possible system power state, achieved only when CPU is in +PKG C10 and all functional blocks in PCH are in a low power state. diff --git a/Documentation/power/pm_qos_interface.txt b/Documentation/power/pm_qos_interface.txt index 21d2d48f87a2..19c5f7b1a7ba 100644 --- a/Documentation/power/pm_qos_interface.txt +++ b/Documentation/power/pm_qos_interface.txt @@ -98,8 +98,7 @@ Values are updated in response to changes of the request list. The target values of resume latency and active state latency tolerance are simply the minimum of the request values held in the parameter list elements. The PM QoS flags aggregate value is a gather (bitwise OR) of all list elements' -values. Two device PM QoS flags are defined currently: PM_QOS_FLAG_NO_POWER_OFF -and PM_QOS_FLAG_REMOTE_WAKEUP. +values. One device PM QoS flag is defined currently: PM_QOS_FLAG_NO_POWER_OFF. Note: The aggregated target values are implemented in such a way that reading the aggregated value does not require any locking mechanism. @@ -153,14 +152,14 @@ PM QoS list of resume latency constraints and remove sysfs attribute pm_qos_resume_latency_us from the device's power directory. int dev_pm_qos_expose_flags(device, value) -Add a request to the device's PM QoS list of flags and create sysfs attributes -pm_qos_no_power_off and pm_qos_remote_wakeup under the device's power directory -allowing user space to change these flags' value. +Add a request to the device's PM QoS list of flags and create sysfs attribute +pm_qos_no_power_off under the device's power directory allowing user space to +change the value of the PM_QOS_FLAG_NO_POWER_OFF flag. void dev_pm_qos_hide_flags(device) Drop the request added by dev_pm_qos_expose_flags() from the device's PM QoS list -of flags and remove sysfs attributes pm_qos_no_power_off and pm_qos_remote_wakeup -under the device's power directory. +of flags and remove sysfs attribute pm_qos_no_power_off from the device's power +directory. Notification mechanisms: The per-device PM QoS framework has a per-device notification tree. |