Revert "PM / runtime: Fixup reference counting of device link suppliers at probe"

Revert commit 1e8378619841 (PM / runtime: Fixup reference counting of
device link suppliers at probe), as it has introduced a regression
and the condition it was designed to address should be covered by the
existing code.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

3 files changed, 30 insertions, 6 deletions

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index a41c91bfac0e..10454fe54482 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -580,7 +580,7 @@ int driver_probe_device(struct device_driver *drv, struct device *dev)
         pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
                  drv->bus->name, __func__, dev_name(dev), drv->name);
 
-        pm_runtime_resume_suppliers(dev);
+        pm_runtime_get_suppliers(dev);
         if (dev->parent)
                 pm_runtime_get_sync(dev->parent);
 
@@ -591,6 +591,7 @@ int driver_probe_device(struct device_driver *drv, struct device *dev)
         if (dev->parent)
                 pm_runtime_put(dev->parent);
 
+        pm_runtime_put_suppliers(dev);
         return ret;
 }
 
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index c6030f100c08..beb85c31f3fa 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1563,16 +1563,37 @@ void pm_runtime_clean_up_links(struct device *dev)
 }
 
 /**
- * pm_runtime_resume_suppliers - Resume supplier devices.
+ * pm_runtime_get_suppliers - Resume and reference-count supplier devices.
  * @dev: Consumer device.
  */
-void pm_runtime_resume_suppliers(struct device *dev)
+void pm_runtime_get_suppliers(struct device *dev)
 {
+        struct device_link *link;
         int idx;
 
         idx = device_links_read_lock();
 
-        rpm_get_suppliers(dev);
+        list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
+                if (link->flags & DL_FLAG_PM_RUNTIME)
+                        pm_runtime_get_sync(link->supplier);
+
+        device_links_read_unlock(idx);
+}
+
+/**
+ * pm_runtime_put_suppliers - Drop references to supplier devices.
+ * @dev: Consumer device.
+ */
+void pm_runtime_put_suppliers(struct device *dev)
+{
+        struct device_link *link;
+        int idx;
+
+        idx = device_links_read_lock();
+
+        list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
+                if (link->flags & DL_FLAG_PM_RUNTIME)
+                        pm_runtime_put(link->supplier);
 
         device_links_read_unlock(idx);
 }
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index db5dbbf7a48d..f0fc4700b6ff 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -56,7 +56,8 @@ extern void pm_runtime_update_max_time_suspended(struct device *dev,
                                                  s64 delta_ns);
 extern void pm_runtime_set_memalloc_noio(struct device *dev, bool enable);
 extern void pm_runtime_clean_up_links(struct device *dev);
-extern void pm_runtime_resume_suppliers(struct device *dev);
+extern void pm_runtime_get_suppliers(struct device *dev);
+extern void pm_runtime_put_suppliers(struct device *dev);
 extern void pm_runtime_new_link(struct device *dev);
 extern void pm_runtime_drop_link(struct device *dev);
 
@@ -172,7 +173,8 @@ static inline unsigned long pm_runtime_autosuspend_expiration(
 static inline void pm_runtime_set_memalloc_noio(struct device *dev,
                                                 bool enable){}
 static inline void pm_runtime_clean_up_links(struct device *dev) {}
-static inline void pm_runtime_resume_suppliers(struct device *dev) {}
+static inline void pm_runtime_get_suppliers(struct device *dev) {}
+static inline void pm_runtime_put_suppliers(struct device *dev) {}
 static inline void pm_runtime_new_link(struct device *dev) {}
 static inline void pm_runtime_drop_link(struct device *dev) {}