cpuidle: create bootparam "cpuidle.off=1"
useful for disabling cpuidle to fall back
to architecture-default idle loop
cpuidle drivers and governors will fail to register.
on x86 they'll say so:
intel_idle: intel_idle yielding to (null)
ACPI: acpi_idle yielding to (null)
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index bf50924..faae2c3 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -28,6 +28,12 @@
static void (*pm_idle_old)(void);
static int enabled_devices;
+static int off __read_mostly;
+
+int cpuidle_disabled(void)
+{
+ return off;
+}
#if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT)
static void cpuidle_kick_cpus(void)
@@ -427,6 +433,9 @@
{
int ret;
+ if (cpuidle_disabled())
+ return -ENODEV;
+
pm_idle_old = pm_idle;
ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
@@ -438,4 +447,5 @@
return 0;
}
+module_param(off, int, 0444);
core_initcall(cpuidle_init);