1 files changed, 30 insertions, 4 deletions

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index ba3487c9835b..55c39f5b7a59 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -777,6 +777,32 @@ static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd)
 }
 
 /**
+ * pm_genpd_sync_poweron - Synchronously power on a PM domain and its masters.
+ * @genpd: PM domain to power on.
+ *
+ * This function is only called in "noirq" stage of system power transitions, so
+ * it need not acquire locks (all of the "noirq" callbacks are executed
+ * sequentially, so it is guaranteed that it will never run twice in parallel).
+ */
+static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd)
+{
+        struct gpd_link *link;
+
+        if (genpd->status != GPD_STATE_POWER_OFF)
+                return;
+
+        list_for_each_entry(link, &genpd->slave_links, slave_node) {
+                pm_genpd_sync_poweron(link->master);
+                genpd_sd_counter_inc(link->master);
+        }
+
+        if (genpd->power_on)
+                genpd->power_on(genpd);
+
+        genpd->status = GPD_STATE_ACTIVE;
+}
+
+/**
  * resume_needed - Check whether to resume a device before system suspend.
  * @dev: Device to check.
  * @genpd: PM domain the device belongs to.
@@ -979,7 +1005,7 @@ static int pm_genpd_resume_noirq(struct device *dev)
          * guaranteed that this function will never run twice in parallel for
          * the same PM domain, so it is not necessary to use locking here.
          */
-        pm_genpd_poweron(genpd);
+        pm_genpd_sync_poweron(genpd);
         genpd->suspended_count--;
 
         return genpd_start_dev(genpd, dev);
@@ -1186,8 +1212,8 @@ static int pm_genpd_restore_noirq(struct device *dev)
         if (genpd->suspended_count++ == 0) {
                 /*
                  * The boot kernel might put the domain into arbitrary state,
-                 * so make it appear as powered off to pm_genpd_poweron(), so
-                 * that it tries to power it on in case it was really off.
+                 * so make it appear as powered off to pm_genpd_sync_poweron(),
+                 * so that it tries to power it on in case it was really off.
                  */
                 genpd->status = GPD_STATE_POWER_OFF;
                 if (genpd->suspend_power_off) {
@@ -1205,7 +1231,7 @@ static int pm_genpd_restore_noirq(struct device *dev)
         if (genpd->suspend_power_off)
                 return 0;
 
-        pm_genpd_poweron(genpd);
+        pm_genpd_sync_poweron(genpd);
 
         return dev_gpd_data(dev)->always_on ? 0 : genpd_start_dev(genpd, dev);
 }