commit 62027aea23fcd14478abdddd3b74a4e0f5fb2984
author Len Brown <len.brown@intel.com> Fri Apr 01 18:13:10 2011 -0400
committer Len Brown <len.brown@intel.com> Wed Aug 03 19:06:36 2011 -0400
tree 1aaa5c1872e296f3448ae6c126175ac9d998e3b4
parent 6dccf9c508d5d773859df1cc2dce75c5b19e35a0

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>

drivers/cpuidle/driver.c

diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index fd1601e..3f7e3ce 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -26,6 +26,9 @@
 	if (!drv)
 		return -EINVAL;
 
+	if (cpuidle_disabled())
+		return -ENODEV;
+
 	spin_lock(&cpuidle_driver_lock);
 	if (cpuidle_curr_driver) {
 		spin_unlock(&cpuidle_driver_lock);