PM / Runtime: Handle .runtime_suspend() failure correctly

If .runtime_suspend() returns -EAGAIN or -EBUSY, the device should
still be in ACTIVE state, so it is not necessary to send an idle
notification to its parent.  If .runtime_suspend() returns other
fatal failure, it doesn't make sense to send idle notification to
its parent.

Skip parent idle notification when failure is returned from
.runtime_suspend() and update comments in rpm_suspend() to reflect
that change.

[rjw: Modified the subject and changelog slightly.]

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

1 files changed, 13 insertions, 12 deletions

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index aa23a64ea33b..6bb3aafa85ed 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -291,11 +291,11 @@ static int rpm_callback(int (*cb)(struct device *), struct device *dev)
  * another suspend has been started earlier, either return immediately
  * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC
  * flags. If the RPM_ASYNC flag is set then queue a suspend request;
- * otherwise run the ->runtime_suspend() callback directly. If a deferred
- * resume was requested while the callback was running then carry it out;
- * otherwise send an idle notification for its parent (if the suspend
- * succeeded and both ignore_children of parent->power and irq_safe of
- * dev->power are not set).
+ * otherwise run the ->runtime_suspend() callback directly. When
+ * ->runtime_suspend succeeded, if a deferred resume was requested while
+ * the callback was running then carry it out, otherwise send an idle
+ * notification for its parent (if the suspend succeeded and both
+ * ignore_children of parent->power and irq_safe of dev->power are not set).
  *
  * This function must be called under dev->power.lock with interrupts disabled.
  */
@@ -420,15 +420,16 @@ static int rpm_suspend(struct device *dev, int rpmflags)
                         dev->power.runtime_error = 0;
                 else
                         pm_runtime_cancel_pending(dev);
-        } else {
+                wake_up_all(&dev->power.wait_queue);
+                goto out;
+        }
  no_callback:
-                __update_runtime_status(dev, RPM_SUSPENDED);
-                pm_runtime_deactivate_timer(dev);
+        __update_runtime_status(dev, RPM_SUSPENDED);
+        pm_runtime_deactivate_timer(dev);
 
-                if (dev->parent) {
-                        parent = dev->parent;
-                        atomic_add_unless(&parent->power.child_count, -1, 0);
-                }
+        if (dev->parent) {
+                parent = dev->parent;
+                atomic_add_unless(&parent->power.child_count, -1, 0);
         }
         wake_up_all(&dev->power.wait_queue);