Merge branch 'pm-runtime'

[linux-drm-fsl-dcu.git] / drivers / base / power / main.c

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 97db7552e90a94ad0a3ba399cc4e2d229b62365c..2a1b06ae0bdc9f758364393d8025a290839b5750 100644 (file)
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -30,6 +30,8 @@
 #include <linux/suspend.h>
 #include <trace/events/power.h>
 #include <linux/cpuidle.h>
+#include <linux/timer.h>
+
 #include "../base.h"
 #include "power.h"
 
@@ -390,6 +392,71 @@ 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 -------------------------*/
 
 /**
@@ -576,6 +643,7 @@ 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);
@@ -584,6 +652,7 @@ 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);
 
        /*
@@ -642,6 +711,7 @@ 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);
@@ -1060,6 +1130,7 @@ 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);
 
@@ -1083,6 +1154,7 @@ 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) {
@@ -1139,6 +1211,7 @@ 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);