diff options
| -rw-r--r-- | Documentation/admin-guide/pm/intel_idle.rst | 13 | ||||
| -rw-r--r-- | drivers/idle/intel_idle.c | 11 |
2 files changed, 18 insertions, 6 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: diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 7833e650789f..6fbd94f85fa5 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -1131,6 +1131,10 @@ static bool no_acpi __read_mostly; module_param(no_acpi, bool, 0444); MODULE_PARM_DESC(no_acpi, "Do not use ACPI _CST for building the idle states list"); +static bool force_use_acpi __read_mostly; /* No effect if no_acpi is set. */ +module_param_named(use_acpi, force_use_acpi, bool, 0444); +MODULE_PARM_DESC(use_acpi, "Use ACPI _CST for building the idle states list"); + static struct acpi_processor_power acpi_state_table __initdata; /** @@ -1258,6 +1262,8 @@ static bool __init intel_idle_off_by_default(u32 mwait_hint) return true; } #else /* !CONFIG_ACPI_PROCESSOR_CSTATE */ +#define force_use_acpi (false) + static inline bool intel_idle_acpi_cst_extract(void) { return false; } static inline void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) { } static inline bool intel_idle_off_by_default(u32 mwait_hint) { return false; } @@ -1460,7 +1466,8 @@ static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv) /* Structure copy. */ drv->states[drv->state_count] = cpuidle_state_table[cstate]; - if (icpu->use_acpi && intel_idle_off_by_default(mwait_hint) && + if ((icpu->use_acpi || force_use_acpi) && + intel_idle_off_by_default(mwait_hint) && !(cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_ALWAYS_ENABLE)) drv->states[drv->state_count].flags |= CPUIDLE_FLAG_OFF; @@ -1607,7 +1614,7 @@ static int __init intel_idle_init(void) icpu = (const struct idle_cpu *)id->driver_data; if (icpu) { cpuidle_state_table = icpu->state_table; - if (icpu->use_acpi) + if (icpu->use_acpi || force_use_acpi) intel_idle_acpi_cst_extract(); } else if (!intel_idle_acpi_cst_extract()) { return -ENODEV; |