PM / sleep: Asynchronous threads for suspend_noirq

In analogy with commits 5af84b82701a and 97df8c12995, using
asynchronous threads can improve the overall suspend_noirq
time significantly.

This patch is for suspend_noirq phase.

Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 6d41165701c4d6492886ecc6fda5ee962d174658..9335b326d1f50870052bc72406d822e32ce975df 100644 (file)
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -990,14 +990,24 @@ static pm_message_t resume_event(pm_message_t sleep_state)
  * The driver of @dev will not receive interrupts while this function is being
  * executed.
  */
-static int device_suspend_noirq(struct device *dev, pm_message_t state)
+static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
 {
        pm_callback_t callback = NULL;
        char *info = NULL;
-       int error;
+       int error = 0;
+
+       if (async_error)
+               goto Complete;
+
+       if (pm_wakeup_pending()) {
+               async_error = -EBUSY;
+               goto Complete;
+       }
 
        if (dev->power.syscore)
-               return 0;
+               goto Complete;
+
+       dpm_wait_for_children(dev, async);
 
        if (dev->pm_domain) {
                info = "noirq power domain ";
@@ -1021,10 +1031,40 @@ static int device_suspend_noirq(struct device *dev, pm_message_t state)
        error = dpm_run_callback(callback, dev, state, info);
        if (!error)
                dev->power.is_noirq_suspended = true;
+       else
+               async_error = error;
 
+Complete:
+       complete_all(&dev->power.completion);
        return error;
 }
 
+static void async_suspend_noirq(void *data, async_cookie_t cookie)
+{
+       struct device *dev = (struct device *)data;
+       int error;
+
+       error = __device_suspend_noirq(dev, pm_transition, true);
+       if (error) {
+               dpm_save_failed_dev(dev_name(dev));
+               pm_dev_err(dev, pm_transition, " async", error);
+       }
+
+       put_device(dev);
+}
+
+static int device_suspend_noirq(struct device *dev)
+{
+       reinit_completion(&dev->power.completion);
+
+       if (pm_async_enabled && dev->power.async_suspend) {
+               get_device(dev);
+               async_schedule(async_suspend_noirq, dev);
+               return 0;
+       }
+       return __device_suspend_noirq(dev, pm_transition, false);
+}
+
 /**
  * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
  * @state: PM transition of the system being carried out.
@@ -1040,19 +1080,20 @@ static int dpm_suspend_noirq(pm_message_t state)
        cpuidle_pause();
        suspend_device_irqs();
        mutex_lock(&dpm_list_mtx);
+       pm_transition = state;
+       async_error = 0;
+
        while (!list_empty(&dpm_late_early_list)) {
                struct device *dev = to_device(dpm_late_early_list.prev);
 
                get_device(dev);
                mutex_unlock(&dpm_list_mtx);
 
-               error = device_suspend_noirq(dev, state);
+               error = device_suspend_noirq(dev);
 
                mutex_lock(&dpm_list_mtx);
                if (error) {
                        pm_dev_err(dev, state, " noirq", error);
-                       suspend_stats.failed_suspend_noirq++;
-                       dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
                        dpm_save_failed_dev(dev_name(dev));
                        put_device(dev);
                        break;
@@ -1061,16 +1102,21 @@ static int dpm_suspend_noirq(pm_message_t state)
                        list_move(&dev->power.entry, &dpm_noirq_list);
                put_device(dev);
 
-               if (pm_wakeup_pending()) {
-                       error = -EBUSY;
+               if (async_error)
                        break;
-               }
        }
        mutex_unlock(&dpm_list_mtx);
-       if (error)
+       async_synchronize_full();
+       if (!error)
+               error = async_error;
+
+       if (error) {
+               suspend_stats.failed_suspend_noirq++;
+               dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
                dpm_resume_noirq(resume_event(state));
-       else
+       } else {
                dpm_show_time(starttime, state, "noirq");
+       }
        return error;
 }