2 files changed, 44 insertions, 3 deletions

diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index 3bed4127d4ad..7dbc4a83c45c 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -1,13 +1,13 @@
 
 config CPU_IDLE
         bool "CPU idle PM support"
+        default ACPI
         help
           CPU idle is a generic framework for supporting software-controlled
           idle processor power management.  It includes modular cross-platform
           governors that can be swapped during runtime.
 
-          If you're using a mobile platform that supports CPU idle PM (e.g.
-          an ACPI-capable notebook), you should say Y here.
+          If you're using an ACPI-enabled platform, you should say Y here.
 
 config CPU_IDLE_GOV_LADDER
         bool
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 2a98d99cbd46..d868d737742f 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -15,6 +15,7 @@
 #include <linux/pm_qos_params.h>
 #include <linux/cpu.h>
 #include <linux/cpuidle.h>
+#include <linux/ktime.h>
 
 #include "cpuidle.h"
 
@@ -82,7 +83,7 @@ void cpuidle_uninstall_idle_handler(void)
 {
         if (enabled_devices && (pm_idle != pm_idle_old)) {
                 pm_idle = pm_idle_old;
-                cpu_idle_wait();
+                cpuidle_kick_cpus();
         }
 }
 
@@ -180,6 +181,44 @@ void cpuidle_disable_device(struct cpuidle_device *dev)
 
 EXPORT_SYMBOL_GPL(cpuidle_disable_device);
 
+#ifdef CONFIG_ARCH_HAS_CPU_RELAX
+static int poll_idle(struct cpuidle_device *dev, struct cpuidle_state *st)
+{
+        ktime_t t1, t2;
+        s64 diff;
+        int ret;
+
+        t1 = ktime_get();
+        local_irq_enable();
+        while (!need_resched())
+                cpu_relax();
+
+        t2 = ktime_get();
+        diff = ktime_to_us(ktime_sub(t2, t1));
+        if (diff > INT_MAX)
+                diff = INT_MAX;
+
+        ret = (int) diff;
+        return ret;
+}
+
+static void poll_idle_init(struct cpuidle_device *dev)
+{
+        struct cpuidle_state *state = &dev->states[0];
+
+        cpuidle_set_statedata(state, NULL);
+
+        snprintf(state->name, CPUIDLE_NAME_LEN, "C0 (poll idle)");
+        state->exit_latency = 0;
+        state->target_residency = 0;
+        state->power_usage = -1;
+        state->flags = CPUIDLE_FLAG_POLL | CPUIDLE_FLAG_TIME_VALID;
+        state->enter = poll_idle;
+}
+#else
+static void poll_idle_init(struct cpuidle_device *dev) {}
+#endif /* CONFIG_ARCH_HAS_CPU_RELAX */
+
 /**
  * cpuidle_register_device - registers a CPU's idle PM feature
  * @dev: the cpu
@@ -198,6 +237,8 @@ int cpuidle_register_device(struct cpuidle_device *dev)
 
         mutex_lock(&cpuidle_lock);
 
+        poll_idle_init(dev);
+
         per_cpu(cpuidle_devices, dev->cpu) = dev;
         list_add(&dev->device_list, &cpuidle_detected_devices);
         if ((ret = cpuidle_add_sysfs(sys_dev))) {