2 files changed, 31 insertions, 0 deletions

diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 72067cbdb37f..91e09d3b2eb2 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -208,3 +208,17 @@ config APM_EMULATION
           random kernel OOPSes or reboots that don't seem to be related to
           anything, try disabling/enabling this option (or disabling/enabling
           APM in your BIOS).
+
+config PM_RUNTIME
+        bool "Run-time PM core functionality"
+        depends on PM
+        ---help---
+          Enable functionality allowing I/O devices to be put into energy-saving
+          (low power) states at run time (or autosuspended) after a specified
+          period of inactivity and woken up in response to a hardware-generated
+          wake-up event or a driver's request.
+
+          Hardware support is generally required for this functionality to work
+          and the bus type drivers of the buses the devices are on are
+          responsible for the actual handling of the autosuspend requests and
+          wake-up events.
diff --git a/kernel/power/main.c b/kernel/power/main.c
index f710e36930cc..347d2cc88cd0 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -11,6 +11,7 @@
 #include <linux/kobject.h>
 #include <linux/string.h>
 #include <linux/resume-trace.h>
+#include <linux/workqueue.h>
 
 #include "power.h"
 
@@ -217,8 +218,24 @@ static struct attribute_group attr_group = {
         .attrs = g,
 };
 
+#ifdef CONFIG_PM_RUNTIME
+struct workqueue_struct *pm_wq;
+
+static int __init pm_start_workqueue(void)
+{
+        pm_wq = create_freezeable_workqueue("pm");
+
+        return pm_wq ? 0 : -ENOMEM;
+}
+#else
+static inline int pm_start_workqueue(void) { return 0; }
+#endif
+
 static int __init pm_init(void)
 {
+        int error = pm_start_workqueue();
+        if (error)
+                return error;
         power_kobj = kobject_create_and_add("power", NULL);
         if (!power_kobj)
                 return -ENOMEM;