6 files changed, 33 insertions, 25 deletions

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 5e1e54197227..d7ee0d4c072d 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -30,6 +30,7 @@
 #include <linux/uaccess.h>
 #include <linux/random.h>
 #include <linux/hw_breakpoint.h>
+#include <linux/cpuidle.h>
 
 #include <asm/cacheflush.h>
 #include <asm/leds.h>
@@ -196,7 +197,8 @@ void cpu_idle(void)
                                 cpu_relax();
                         } else {
                                 stop_critical_timings();
-                                pm_idle();
+                                if (cpuidle_call_idle())
+                                        pm_idle();
                                 start_critical_timings();
                                 /*
                                  * This will eventually be removed - pm_idle
diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c
index 425d604e3a28..9c7099ebfe14 100644
--- a/arch/sh/kernel/idle.c
+++ b/arch/sh/kernel/idle.c
@@ -16,12 +16,13 @@
 #include <linux/thread_info.h>
 #include <linux/irqflags.h>
 #include <linux/smp.h>
+#include <linux/cpuidle.h>
 #include <asm/pgalloc.h>
 #include <asm/system.h>
 #include <asm/atomic.h>
 #include <asm/smp.h>
 
-void (*pm_idle)(void) = NULL;
+static void (*pm_idle)(void);
 
 static int hlt_counter;
 
@@ -100,7 +101,8 @@ void cpu_idle(void)
                         local_irq_disable();
                         /* Don't trace irqs off for idle */
                         stop_critical_timings();
-                        pm_idle();
+                        if (cpuidle_call_idle())
+                                pm_idle();
                         /*
                          * Sanity check to ensure that pm_idle() returns
                          * with IRQs enabled
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index a3d0dc59067b..7a3b65107a27 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -38,6 +38,7 @@
 #include <linux/uaccess.h>
 #include <linux/io.h>
 #include <linux/kdebug.h>
+#include <linux/cpuidle.h>
 
 #include <asm/pgtable.h>
 #include <asm/system.h>
@@ -109,7 +110,8 @@ void cpu_idle(void)
                         local_irq_disable();
                         /* Don't trace irqs off for idle */
                         stop_critical_timings();
-                        pm_idle();
+                        if (cpuidle_idle_call())
+                                pm_idle();
                         start_critical_timings();
                 }
                 tick_nohz_restart_sched_tick();
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index ca6f7ab8df33..f693e44e1bf6 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -37,6 +37,7 @@
 #include <linux/uaccess.h>
 #include <linux/io.h>
 #include <linux/ftrace.h>
+#include <linux/cpuidle.h>
 
 #include <asm/pgtable.h>
 #include <asm/system.h>
@@ -136,7 +137,8 @@ void cpu_idle(void)
                         enter_idle();
                         /* Don't trace irqs off for idle */
                         stop_critical_timings();
-                        pm_idle();
+                        if (cpuidle_idle_call())
+                                pm_idle();
                         start_critical_timings();
 
                         /* In many cases the interrupt that ended idle
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 041df0b056b2..d4c542372886 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -25,10 +25,10 @@ DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 
 DEFINE_MUTEX(cpuidle_lock);
 LIST_HEAD(cpuidle_detected_devices);
-static void (*pm_idle_old)(void);
 
 static int enabled_devices;
 static int off __read_mostly;
+static int initialized __read_mostly;
 
 int cpuidle_disabled(void)
 {
@@ -56,25 +56,23 @@ static int __cpuidle_register_device(struct cpuidle_device *dev);
  * cpuidle_idle_call - the main idle loop
  *
  * NOTE: no locks or semaphores should be used here
+ * return non-zero on failure
  */
-static void cpuidle_idle_call(void)
+int cpuidle_idle_call(void)
 {
         struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
         struct cpuidle_state *target_state;
         int next_state;
 
+        if (off)
+                return -ENODEV;
+
+        if (!initialized)
+                return -ENODEV;
+
         /* check if the device is ready */
-        if (!dev || !dev->enabled) {
-                if (pm_idle_old)
-                        pm_idle_old();
-                else
-#if defined(CONFIG_ARCH_HAS_DEFAULT_IDLE)
-                        default_idle();
-#else
-                        local_irq_enable();
-#endif
-                return;
-        }
+        if (!dev || !dev->enabled)
+                return -EBUSY;
 
 #if 0
         /* shows regressions, re-enable for 2.6.29 */
@@ -99,7 +97,7 @@ static void cpuidle_idle_call(void)
         next_state = cpuidle_curr_governor->select(dev);
         if (need_resched()) {
                 local_irq_enable();
-                return;
+                return 0;
         }
 
         target_state = &dev->states[next_state];
@@ -124,6 +122,8 @@ static void cpuidle_idle_call(void)
         /* give the governor an opportunity to reflect on the outcome */
         if (cpuidle_curr_governor->reflect)
                 cpuidle_curr_governor->reflect(dev);
+
+        return 0;
 }
 
 /**
@@ -131,10 +131,10 @@ static void cpuidle_idle_call(void)
  */
 void cpuidle_install_idle_handler(void)
 {
-        if (enabled_devices && (pm_idle != cpuidle_idle_call)) {
+        if (enabled_devices) {
                 /* Make sure all changes finished before we switch to new idle */
                 smp_wmb();
-                pm_idle = cpuidle_idle_call;
+                initialized = 1;
         }
 }
 
@@ -143,8 +143,8 @@ void cpuidle_install_idle_handler(void)
  */
 void cpuidle_uninstall_idle_handler(void)
 {
-        if (enabled_devices && pm_idle_old && (pm_idle != pm_idle_old)) {
-                pm_idle = pm_idle_old;
+        if (enabled_devices) {
+                initialized = 0;
                 cpuidle_kick_cpus();
         }
 }
@@ -440,8 +440,6 @@ static int __init cpuidle_init(void)
         if (cpuidle_disabled())
                 return -ENODEV;
 
-        pm_idle_old = pm_idle;
-
         ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
         if (ret)
                 return ret;
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index b89f67da919e..b51629e15cfc 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -123,6 +123,7 @@ struct cpuidle_driver {
 
 #ifdef CONFIG_CPU_IDLE
 extern void disable_cpuidle(void);
+extern int cpuidle_idle_call(void);
 
 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 struct cpuidle_driver *cpuidle_get_driver(void);
@@ -137,6 +138,7 @@ extern void cpuidle_disable_device(struct cpuidle_device *dev);
 
 #else
 static inline void disable_cpuidle(void) { }
+static inline int cpuidle_idle_call(void) { return -ENODEV; }
 
 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 {return -ENODEV; }