2 files changed, 55 insertions, 0 deletions

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 06f09bf..4282d44 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -27,6 +27,7 @@
 #include <linux/sched.h>
 #include <linux/async.h>
 #include <linux/suspend.h>
+#include <linux/timer.h>
 
 #include "../base.h"
 #include "power.h"
@@ -49,6 +50,12 @@ LIST_HEAD(dpm_noirq_list);
 static DEFINE_MUTEX(dpm_list_mtx);
 static pm_message_t pm_transition;
 
+static void dpm_drv_timeout(unsigned long data);
+struct dpm_drv_wd_data {
+	struct device *dev;
+	struct task_struct *tsk;
+};
+
 static int async_error;
 
 /**
@@ -584,6 +591,30 @@ static bool is_async(struct device *dev)
 }
 
 /**
+ *	dpm_drv_timeout - Driver suspend / resume watchdog handler
+ *	@data: struct device which timed out
+ *
+ * 	Called when a driver has timed out suspending or resuming.
+ * 	There's not much we can do here to recover so
+ * 	BUG() out for a crash-dump
+ *
+ */
+static void dpm_drv_timeout(unsigned long data)
+{
+	struct dpm_drv_wd_data *wd_data = (void *)data;
+	struct device *dev = wd_data->dev;
+	struct task_struct *tsk = wd_data->tsk;
+
+	printk(KERN_EMERG "**** DPM device timeout: %s (%s)\n", dev_name(dev),
+	       (dev->driver ? dev->driver->name : "no driver"));
+
+	printk(KERN_EMERG "dpm suspend stack:\n");
+	show_stack(tsk, NULL);
+
+	BUG();
+}
+
+/**
  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
  * @state: PM transition of the system being carried out.
  *
@@ -841,8 +872,19 @@ static int legacy_suspend(struct device *dev, pm_message_t state,
 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 {
 	int error = 0;
+	struct timer_list timer;
+	struct dpm_drv_wd_data data;
 
 	dpm_wait_for_children(dev, async);
+
+	data.dev = dev;
+	data.tsk = get_current();
+	init_timer_on_stack(&timer);
+	timer.expires = jiffies + HZ * 12;
+	timer.function = dpm_drv_timeout;
+	timer.data = (unsigned long)&data;
+	add_timer(&timer);
+
 	device_lock(dev);
 
 	if (async_error)
@@ -892,6 +934,10 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 
  Unlock:
 	device_unlock(dev);
+
+	del_timer_sync(&timer);
+	destroy_timer_on_stack(&timer);
+
 	complete_all(&dev->power.completion);
 
 	if (error)
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 1023392..184cf54 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -746,6 +746,8 @@ int __pm_runtime_idle(struct device *dev, int rpmflags)
 	unsigned long flags;
 	int retval;
 
+	might_sleep_if(!(rpmflags & RPM_ASYNC));
+
 	if (rpmflags & RPM_GET_PUT) {
 		if (!atomic_dec_and_test(&dev->power.usage_count))
 			return 0;
@@ -775,6 +777,8 @@ int __pm_runtime_suspend(struct device *dev, int rpmflags)
 	unsigned long flags;
 	int retval;
 
+	might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
+
 	if (rpmflags & RPM_GET_PUT) {
 		if (!atomic_dec_and_test(&dev->power.usage_count))
 			return 0;
@@ -803,6 +807,8 @@ int __pm_runtime_resume(struct device *dev, int rpmflags)
 	unsigned long flags;
 	int retval;
 
+	might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
+
 	if (rpmflags & RPM_GET_PUT)
 		atomic_inc(&dev->power.usage_count);
 
@@ -992,6 +998,7 @@ EXPORT_SYMBOL_GPL(pm_runtime_barrier);
  */
 void __pm_runtime_disable(struct device *dev, bool check_resume)
 {
+	might_sleep();
 	spin_lock_irq(&dev->power.lock);
 
 	if (dev->power.disable_depth > 0) {
@@ -1198,6 +1205,8 @@ void __pm_runtime_use_autosuspend(struct device *dev, bool use)
 {
 	int old_delay, old_use;
 
+	might_sleep();
+
 	spin_lock_irq(&dev->power.lock);
 	old_delay = dev->power.autosuspend_delay;
 	old_use = dev->power.use_autosuspend;