intel_idle: native hardware cpuidle driver for latest Intel processors
This EXPERIMENTAL driver supersedes acpi_idle on
Intel Atom Processors, Intel Core i3/i5/i7 Processors
and associated Intel Xeon processors.
It does not support the Intel Core2 processor or earlier.
For kernels configured with ACPI, CONFIG_INTEL_IDLE=y
allows intel_idle to probe before the ACPI processor driver.
Booting with "intel_idle.max_cstate=0" disables intel_idle
and the system will fall back on ACPI's "acpi_idle".
Typical Linux distributions load ACPI processor module early,
making CONFIG_INTEL_IDLE=m not easily useful on ACPI platforms.
intel_idle probes all processors at module_init time.
Processors that are hot-added later will be limited
to using C1 in idle.
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index deefa85..b1034a9 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -922,9 +922,13 @@
return -ENOMEM;
#endif
- if (!cpuidle_register_driver(&acpi_idle_driver))
+ if (!cpuidle_register_driver(&acpi_idle_driver)) {
printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
acpi_idle_driver.name);
+ } else {
+ printk(KERN_DEBUG "ACPI: acpi_idle yielding to %s",
+ cpuidle_get_driver()->name);
+ }
result = acpi_bus_register_driver(&acpi_processor_driver);
if (result < 0)