Merge tag 'pm-for-3.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael J. Wysocki:
  - Fixes for three obscure problems in the runtime PM core code found
   recently.
 - Two fixes for the new "coupled" cpuidle code from Colin Cross and Jon
   Medhurst.
 - intel_idle driver fix from Konrad Rzeszutek Wilk.

* tag 'pm-for-3.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  intel_idle: Check cpu_idle_get_driver() for NULL before dereferencing it.
  cpuidle: Prevent null pointer dereference in cpuidle_coupled_cpu_notify
  cpuidle: coupled: fix sleeping while atomic in cpu notifier
  PM / Runtime: Check device PM QoS setting before "no callbacks" check
  PM / Runtime: Clear power.deferred_resume on success in rpm_suspend()
  PM / Runtime: Fix rpm_resume() return value for power.no_callbacks set

3 files changed, 20 insertions, 10 deletions

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 59894873a3b3..7d9c1cb1c39a 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -147,6 +147,8 @@ static int rpm_check_suspend_allowed(struct device *dev)
             || (dev->power.request_pending
                         && dev->power.request == RPM_REQ_RESUME))
                 retval = -EAGAIN;
+        else if (__dev_pm_qos_read_value(dev) < 0)
+                retval = -EPERM;
         else if (dev->power.runtime_status == RPM_SUSPENDED)
                 retval = 1;
 
@@ -388,7 +390,6 @@ static int rpm_suspend(struct device *dev, int rpmflags)
                 goto repeat;
         }
 
-        dev->power.deferred_resume = false;
         if (dev->power.no_callbacks)
                 goto no_callback;       /* Assume success. */
 
@@ -403,12 +404,6 @@ static int rpm_suspend(struct device *dev, int rpmflags)
                 goto out;
         }
 
-        if (__dev_pm_qos_read_value(dev) < 0) {
-                /* Negative PM QoS constraint means "never suspend". */
-                retval = -EPERM;
-                goto out;
-        }
-
         __update_runtime_status(dev, RPM_SUSPENDING);
 
         if (dev->pm_domain)
@@ -440,6 +435,7 @@ static int rpm_suspend(struct device *dev, int rpmflags)
         wake_up_all(&dev->power.wait_queue);
 
         if (dev->power.deferred_resume) {
+                dev->power.deferred_resume = false;
                 rpm_resume(dev, 0);
                 retval = -EAGAIN;
                 goto out;
@@ -584,6 +580,7 @@ static int rpm_resume(struct device *dev, int rpmflags)
                     || dev->parent->power.runtime_status == RPM_ACTIVE) {
                         atomic_inc(&dev->parent->power.child_count);
                         spin_unlock(&dev->parent->power.lock);
+                        retval = 1;
                         goto no_callback;       /* Assume success. */
                 }
                 spin_unlock(&dev->parent->power.lock);
@@ -664,7 +661,7 @@ static int rpm_resume(struct device *dev, int rpmflags)
         }
         wake_up_all(&dev->power.wait_queue);
 
-        if (!retval)
+        if (retval >= 0)
                 rpm_idle(dev, RPM_ASYNC);
 
  out:
diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c
index 2c9bf2692232..3265844839bf 100644
--- a/drivers/cpuidle/coupled.c
+++ b/drivers/cpuidle/coupled.c
@@ -678,10 +678,22 @@ static int cpuidle_coupled_cpu_notify(struct notifier_block *nb,
         int cpu = (unsigned long)hcpu;
         struct cpuidle_device *dev;
 
+        switch (action & ~CPU_TASKS_FROZEN) {
+        case CPU_UP_PREPARE:
+        case CPU_DOWN_PREPARE:
+        case CPU_ONLINE:
+        case CPU_DEAD:
+        case CPU_UP_CANCELED:
+        case CPU_DOWN_FAILED:
+                break;
+        default:
+                return NOTIFY_OK;
+        }
+
         mutex_lock(&cpuidle_lock);
 
         dev = per_cpu(cpuidle_devices, cpu);
-        if (!dev->coupled)
+        if (!dev || !dev->coupled)
                 goto out;
 
         switch (action & ~CPU_TASKS_FROZEN) {
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index f559088869f6..e8726177d103 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -606,8 +606,9 @@ static int __init intel_idle_init(void)
         intel_idle_cpuidle_driver_init();
         retval = cpuidle_register_driver(&intel_idle_driver);
         if (retval) {
+                struct cpuidle_driver *drv = cpuidle_get_driver();
                 printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
-                        cpuidle_get_driver()->name);
+                        drv ? drv->name : "none");
                 return retval;
         }