UPSTREAM: PM / Domains: Remove redundant pm_runtime_get|put*() in pm_genpd_prepare()
[firefly-linux-kernel-4.4.55.git] / drivers / base / power / domain.c
index 167418e73445a4f69b372f9205f65ca43f525c9d..e36c01c8b0672777e83308016a4e3a237ea33df8 100644 (file)
@@ -170,16 +170,15 @@ static void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
        queue_work(pm_wq, &genpd->power_off_work);
 }
 
-static int genpd_poweron(struct generic_pm_domain *genpd);
-
 /**
  * __genpd_poweron - Restore power to a given PM domain and its masters.
  * @genpd: PM domain to power up.
+ * @depth: nesting count for lockdep.
  *
  * Restore power to @genpd and all of its masters so that it is possible to
  * resume a device belonging to it.
  */
-static int __genpd_poweron(struct generic_pm_domain *genpd)
+static int __genpd_poweron(struct generic_pm_domain *genpd, unsigned int depth)
 {
        struct gpd_link *link;
        int ret = 0;
@@ -194,11 +193,16 @@ static int __genpd_poweron(struct generic_pm_domain *genpd)
         * with it.
         */
        list_for_each_entry(link, &genpd->slave_links, slave_node) {
-               genpd_sd_counter_inc(link->master);
+               struct generic_pm_domain *master = link->master;
+
+               genpd_sd_counter_inc(master);
+
+               mutex_lock_nested(&master->lock, depth + 1);
+               ret = __genpd_poweron(master, depth + 1);
+               mutex_unlock(&master->lock);
 
-               ret = genpd_poweron(link->master);
                if (ret) {
-                       genpd_sd_counter_dec(link->master);
+                       genpd_sd_counter_dec(master);
                        goto err;
                }
        }
@@ -230,11 +234,12 @@ static int genpd_poweron(struct generic_pm_domain *genpd)
        int ret;
 
        mutex_lock(&genpd->lock);
-       ret = __genpd_poweron(genpd);
+       ret = __genpd_poweron(genpd, 0);
        mutex_unlock(&genpd->lock);
        return ret;
 }
 
+
 static int genpd_save_dev(struct generic_pm_domain *genpd, struct device *dev)
 {
        return GENPD_DEV_CALLBACK(genpd, int, save_state, dev);
@@ -390,6 +395,7 @@ static int pm_genpd_runtime_suspend(struct device *dev)
        struct generic_pm_domain *genpd;
        bool (*stop_ok)(struct device *__dev);
        struct gpd_timing_data *td = &dev_gpd_data(dev)->td;
+       bool runtime_pm = pm_runtime_enabled(dev);
        ktime_t time_start;
        s64 elapsed_ns;
        int ret;
@@ -400,12 +406,19 @@ static int pm_genpd_runtime_suspend(struct device *dev)
        if (IS_ERR(genpd))
                return -EINVAL;
 
+       /*
+        * A runtime PM centric subsystem/driver may re-use the runtime PM
+        * callbacks for other purposes than runtime PM. In those scenarios
+        * runtime PM is disabled. Under these circumstances, we shall skip
+        * validating/measuring the PM QoS latency.
+        */
        stop_ok = genpd->gov ? genpd->gov->stop_ok : NULL;
-       if (stop_ok && !stop_ok(dev))
+       if (runtime_pm && stop_ok && !stop_ok(dev))
                return -EBUSY;
 
        /* Measure suspend latency. */
-       time_start = ktime_get();
+       if (runtime_pm)
+               time_start = ktime_get();
 
        ret = genpd_save_dev(genpd, dev);
        if (ret)
@@ -418,13 +431,15 @@ static int pm_genpd_runtime_suspend(struct device *dev)
        }
 
        /* Update suspend latency value if the measured time exceeds it. */
-       elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
-       if (elapsed_ns > td->suspend_latency_ns) {
-               td->suspend_latency_ns = elapsed_ns;
-               dev_dbg(dev, "suspend latency exceeded, %lld ns\n",
-                       elapsed_ns);
-               genpd->max_off_time_changed = true;
-               td->constraint_changed = true;
+       if (runtime_pm) {
+               elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
+               if (elapsed_ns > td->suspend_latency_ns) {
+                       td->suspend_latency_ns = elapsed_ns;
+                       dev_dbg(dev, "suspend latency exceeded, %lld ns\n",
+                               elapsed_ns);
+                       genpd->max_off_time_changed = true;
+                       td->constraint_changed = true;
+               }
        }
 
        /*
@@ -453,6 +468,7 @@ static int pm_genpd_runtime_resume(struct device *dev)
 {
        struct generic_pm_domain *genpd;
        struct gpd_timing_data *td = &dev_gpd_data(dev)->td;
+       bool runtime_pm = pm_runtime_enabled(dev);
        ktime_t time_start;
        s64 elapsed_ns;
        int ret;
@@ -471,7 +487,7 @@ static int pm_genpd_runtime_resume(struct device *dev)
        }
 
        mutex_lock(&genpd->lock);
-       ret = __genpd_poweron(genpd);
+       ret = __genpd_poweron(genpd, 0);
        mutex_unlock(&genpd->lock);
 
        if (ret)
@@ -479,14 +495,14 @@ static int pm_genpd_runtime_resume(struct device *dev)
 
  out:
        /* Measure resume latency. */
-       if (timed)
+       if (timed && runtime_pm)
                time_start = ktime_get();
 
        genpd_start_dev(genpd, dev);
        genpd_restore_dev(genpd, dev);
 
        /* Update resume latency value if the measured time exceeds it. */
-       if (timed) {
+       if (timed && runtime_pm) {
                elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
                if (elapsed_ns > td->resume_latency_ns) {
                        td->resume_latency_ns = elapsed_ns;
@@ -672,14 +688,11 @@ static int pm_genpd_prepare(struct device *dev)
         * at this point and a system wakeup event should be reported if it's
         * set up to wake up the system from sleep states.
         */
-       pm_runtime_get_noresume(dev);
        if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
                pm_wakeup_event(dev, 0);
 
-       if (pm_wakeup_pending()) {
-               pm_runtime_put(dev);
+       if (pm_wakeup_pending())
                return -EBUSY;
-       }
 
        if (resume_needed(dev, genpd))
                pm_runtime_resume(dev);
@@ -693,10 +706,8 @@ static int pm_genpd_prepare(struct device *dev)
 
        mutex_unlock(&genpd->lock);
 
-       if (genpd->suspend_power_off) {
-               pm_runtime_put_noidle(dev);
+       if (genpd->suspend_power_off)
                return 0;
-       }
 
        /*
         * The PM domain must be in the GPD_STATE_ACTIVE state at this point,
@@ -718,7 +729,6 @@ static int pm_genpd_prepare(struct device *dev)
                pm_runtime_enable(dev);
        }
 
-       pm_runtime_put(dev);
        return ret;
 }
 
@@ -1322,8 +1332,8 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
        if (!link)
                return -ENOMEM;
 
-       mutex_lock(&genpd->lock);
-       mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
+       mutex_lock(&subdomain->lock);
+       mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING);
 
        if (genpd->status == GPD_STATE_POWER_OFF
            &&  subdomain->status != GPD_STATE_POWER_OFF) {
@@ -1346,8 +1356,8 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
                genpd_sd_counter_inc(genpd);
 
  out:
-       mutex_unlock(&subdomain->lock);
        mutex_unlock(&genpd->lock);
+       mutex_unlock(&subdomain->lock);
        if (ret)
                kfree(link);
        return ret;
@@ -1368,9 +1378,10 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
        if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
                return -EINVAL;
 
-       mutex_lock(&genpd->lock);
+       mutex_lock(&subdomain->lock);
+       mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING);
 
-       if (!list_empty(&subdomain->slave_links) || subdomain->device_count) {
+       if (!list_empty(&subdomain->master_links) || subdomain->device_count) {
                pr_warn("%s: unable to remove subdomain %s\n", genpd->name,
                        subdomain->name);
                ret = -EBUSY;
@@ -1381,22 +1392,19 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
                if (link->slave != subdomain)
                        continue;
 
-               mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
-
                list_del(&link->master_node);
                list_del(&link->slave_node);
                kfree(link);
                if (subdomain->status != GPD_STATE_POWER_OFF)
                        genpd_sd_counter_dec(genpd);
 
-               mutex_unlock(&subdomain->lock);
-
                ret = 0;
                break;
        }
 
 out:
        mutex_unlock(&genpd->lock);
+       mutex_unlock(&subdomain->lock);
 
        return ret;
 }