Merge branches 'pm-cpuidle' and 'pm-cpufreq'
[sfrench/cifs-2.6.git] / drivers / base / power / main.c
index 10c3510d72a9426ad91dd4f76ec94db01239fa52..e3219dfd736c64fbf13976ce3fa7f66b89e6484e 100644 (file)
@@ -31,6 +31,8 @@
 #include <trace/events/power.h>
 #include <linux/cpufreq.h>
 #include <linux/cpuidle.h>
+#include <linux/timer.h>
+
 #include "../base.h"
 #include "power.h"
 
@@ -391,6 +393,71 @@ static int dpm_run_callback(pm_callback_t cb, struct device *dev,
        return error;
 }
 
+#ifdef CONFIG_DPM_WATCHDOG
+struct dpm_watchdog {
+       struct device           *dev;
+       struct task_struct      *tsk;
+       struct timer_list       timer;
+};
+
+#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
+       struct dpm_watchdog wd
+
+/**
+ * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
+ * @data: Watchdog object address.
+ *
+ * Called when a driver has timed out suspending or resuming.
+ * There's not much we can do here to recover so panic() to
+ * capture a crash-dump in pstore.
+ */
+static void dpm_watchdog_handler(unsigned long data)
+{
+       struct dpm_watchdog *wd = (void *)data;
+
+       dev_emerg(wd->dev, "**** DPM device timeout ****\n");
+       show_stack(wd->tsk, NULL);
+       panic("%s %s: unrecoverable failure\n",
+               dev_driver_string(wd->dev), dev_name(wd->dev));
+}
+
+/**
+ * dpm_watchdog_set - Enable pm watchdog for given device.
+ * @wd: Watchdog. Must be allocated on the stack.
+ * @dev: Device to handle.
+ */
+static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
+{
+       struct timer_list *timer = &wd->timer;
+
+       wd->dev = dev;
+       wd->tsk = current;
+
+       init_timer_on_stack(timer);
+       /* use same timeout value for both suspend and resume */
+       timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
+       timer->function = dpm_watchdog_handler;
+       timer->data = (unsigned long)wd;
+       add_timer(timer);
+}
+
+/**
+ * dpm_watchdog_clear - Disable suspend/resume watchdog.
+ * @wd: Watchdog to disable.
+ */
+static void dpm_watchdog_clear(struct dpm_watchdog *wd)
+{
+       struct timer_list *timer = &wd->timer;
+
+       del_timer_sync(timer);
+       destroy_timer_on_stack(timer);
+}
+#else
+#define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
+#define dpm_watchdog_set(x, y)
+#define dpm_watchdog_clear(x)
+#endif
+
 /*------------------------- Resume routines -------------------------*/
 
 /**
@@ -578,6 +645,7 @@ static int device_resume(struct device *dev, pm_message_t state, bool async)
        pm_callback_t callback = NULL;
        char *info = NULL;
        int error = 0;
+       DECLARE_DPM_WATCHDOG_ON_STACK(wd);
 
        TRACE_DEVICE(dev);
        TRACE_RESUME(0);
@@ -586,6 +654,7 @@ static int device_resume(struct device *dev, pm_message_t state, bool async)
                goto Complete;
 
        dpm_wait(dev->parent, async);
+       dpm_watchdog_set(&wd, dev);
        device_lock(dev);
 
        /*
@@ -644,6 +713,7 @@ static int device_resume(struct device *dev, pm_message_t state, bool async)
 
  Unlock:
        device_unlock(dev);
+       dpm_watchdog_clear(&wd);
 
  Complete:
        complete_all(&dev->power.completion);
@@ -689,7 +759,7 @@ void dpm_resume(pm_message_t state)
        async_error = 0;
 
        list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
-               INIT_COMPLETION(dev->power.completion);
+               reinit_completion(&dev->power.completion);
                if (is_async(dev)) {
                        get_device(dev);
                        async_schedule(async_resume, dev);
@@ -1063,6 +1133,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
        pm_callback_t callback = NULL;
        char *info = NULL;
        int error = 0;
+       DECLARE_DPM_WATCHDOG_ON_STACK(wd);
 
        dpm_wait_for_children(dev, async);
 
@@ -1086,6 +1157,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
        if (dev->power.syscore)
                goto Complete;
 
+       dpm_watchdog_set(&wd, dev);
        device_lock(dev);
 
        if (dev->pm_domain) {
@@ -1142,6 +1214,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
        }
 
        device_unlock(dev);
+       dpm_watchdog_clear(&wd);
 
  Complete:
        complete_all(&dev->power.completion);
@@ -1167,7 +1240,7 @@ static void async_suspend(void *data, async_cookie_t cookie)
 
 static int device_suspend(struct device *dev)
 {
-       INIT_COMPLETION(dev->power.completion);
+       reinit_completion(&dev->power.completion);
 
        if (pm_async_enabled && dev->power.async_suspend) {
                get_device(dev);
@@ -1280,6 +1353,9 @@ static int device_prepare(struct device *dev, pm_message_t state)
 
        device_unlock(dev);
 
+       if (error)
+               pm_runtime_put(dev);
+
        return error;
 }