From 4ec32d9e8e5b6d6eb491eeee3938665d8a2388fa Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 13 Dec 2019 09:56:29 +0100 Subject: [PATCH] intel_idle: Add module parameter to prevent ACPI _CST from being used Add a new module parameter called "no_acpi" to the intel_idle driver to allow the driver to be prevented from using ACPI _CST via kernel command line. Signed-off-by: Rafael J. Wysocki --- drivers/idle/intel_idle.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index a072b84d9595..26fe383bb921 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -1138,6 +1138,10 @@ static bool intel_idle_max_cstate_reached(int cstate) #ifdef CONFIG_ACPI_PROCESSOR_CSTATE #include +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 struct acpi_processor_power acpi_state_table; /** @@ -1167,6 +1171,11 @@ static bool intel_idle_acpi_cst_extract(void) { unsigned int cpu; + if (no_acpi) { + pr_debug("Not allowed to use ACPI _CST\n"); + return false; + } + for_each_possible_cpu(cpu) { struct acpi_processor *pr = per_cpu(processors, cpu); -- 2.20.1