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Diffstat (limited to 'Documentation/acpi/lpit.txt')
| -rw-r--r-- | Documentation/acpi/lpit.txt | 25 |
1 files changed, 0 insertions, 25 deletions
diff --git a/Documentation/acpi/lpit.txt b/Documentation/acpi/lpit.txt deleted file mode 100644 index b426398d2e97..000000000000 --- a/Documentation/acpi/lpit.txt +++ /dev/null @@ -1,25 +0,0 @@ -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. |