Merge tag 'pm-3.11-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fix from Rafael Wysocki:
 "The removal of delayed_work_pending() checks from kernel/power/qos.c
  done in 3.9 introduced a deadlock in pm_qos_work_fn().

  Fix from Stephen Boyd"

* tag 'pm-3.11-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / QoS: Fix workqueue deadlock when using pm_qos_update_request_timeout()

1 files changed, 13 insertions, 7 deletions

diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index 06fe28589e9c..a394297f8b2f 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -296,6 +296,17 @@ int pm_qos_request_active(struct pm_qos_request *req)
 }
 EXPORT_SYMBOL_GPL(pm_qos_request_active);
 
+static void __pm_qos_update_request(struct pm_qos_request *req,
+                           s32 new_value)
+{
+        trace_pm_qos_update_request(req->pm_qos_class, new_value);
+
+        if (new_value != req->node.prio)
+                pm_qos_update_target(
+                        pm_qos_array[req->pm_qos_class]->constraints,
+                        &req->node, PM_QOS_UPDATE_REQ, new_value);
+}
+
 /**
  * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout
  * @work: work struct for the delayed work (timeout)
@@ -308,7 +319,7 @@ static void pm_qos_work_fn(struct work_struct *work)
                                                   struct pm_qos_request,
                                                   work);
 
-        pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE);
+        __pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE);
 }
 
 /**
@@ -364,12 +375,7 @@ void pm_qos_update_request(struct pm_qos_request *req,
         }
 
         cancel_delayed_work_sync(&req->work);
-
-        trace_pm_qos_update_request(req->pm_qos_class, new_value);
-        if (new_value != req->node.prio)
-                pm_qos_update_target(
-                        pm_qos_array[req->pm_qos_class]->constraints,
-                        &req->node, PM_QOS_UPDATE_REQ, new_value);
+        __pm_qos_update_request(req, new_value);
 }
 EXPORT_SYMBOL_GPL(pm_qos_update_request);