diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2020-02-03 11:57:08 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2020-02-03 11:57:08 +0100 |
| commit | 3a5be9b8f43346a24f31c0017cb2566a6b2c72c5 (patch) | |
| tree | 346315651d61e9e5ee7e7263a76dff66e5346db8 /Documentation/admin-guide | |
| parent | cf3c8f84d1401fed5010784034d104cc689061d5 (diff) | |
intel_idle: Introduce 'use_acpi' module parameter
For diagnostics, it is generally useful to be able to make intel_idle
take the system's ACPI tables into consideration even if that is not
required for the processor model in there, so introduce a new module
parameter, 'use_acpi', to make that happen and update the documentation
to cover it.
While at it, fix the 'no_acpi' module parameter name in the
documentation.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/pm/intel_idle.rst | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/Documentation/admin-guide/pm/intel_idle.rst b/Documentation/admin-guide/pm/intel_idle.rst index afbf778035f8..8998598746a4 100644 --- a/Documentation/admin-guide/pm/intel_idle.rst +++ b/Documentation/admin-guide/pm/intel_idle.rst @@ -60,6 +60,9 @@ of the system. The former are always used if the processor model at hand is recognized by ``intel_idle`` and the latter are used if that is required for the given processor model (which is the case for all server processor models recognized by ``intel_idle``) or if the processor model is not recognized. +[There is a module parameter that can be used to make the driver use the ACPI +tables with any processor model recognized by it; see +`below <intel-idle-parameters_>`_.] If the ACPI tables are going to be used for building the list of available idle states, ``intel_idle`` first looks for a ``_CST`` object under one of the ACPI @@ -165,7 +168,7 @@ and ``idle=nomwait``. If any of them is present in the kernel command line, the ``MWAIT`` instruction is not allowed to be used, so the initialization of ``intel_idle`` will fail. -Apart from that there are two module parameters recognized by ``intel_idle`` +Apart from that there are three module parameters recognized by ``intel_idle`` itself that can be set via the kernel command line (they cannot be updated via sysfs, so that is the only way to change their values). @@ -186,9 +189,11 @@ QoS) feature can be used to prevent ``CPUIdle`` from touching those idle states even if they have been enumerated (see :ref:`cpu-pm-qos` in :doc:`cpuidle`). Setting ``max_cstate`` to 0 causes the ``intel_idle`` initialization to fail. -The ``noacpi`` module parameter (which is recognized by ``intel_idle`` if the -kernel has been configured with ACPI support), can be set to make the driver -ignore the system's ACPI tables entirely (it is unset by default). +The ``no_acpi`` and ``use_acpi`` module parameters (recognized by ``intel_idle`` +if the kernel has been configured with ACPI support) can be set to make the +driver ignore the system's ACPI tables entirely or use them for all of the +recognized processor models, respectively (they both are unset by default and +``use_acpi`` has no effect if ``no_acpi`` is set). .. _intel-idle-core-and-package-idle-states: |