PM: Add a switch for disabling/enabling asynchronous suspend/resume
Add sysfs attribute /sys/power/pm_async allowing the user space to
disable/enable asynchronous suspend/resume of devices.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 0998c71..b58800b 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -44,6 +44,32 @@
== NOTIFY_BAD) ? -EINVAL : 0;
}
+/* If set, devices may be suspended and resumed asynchronously. */
+int pm_async_enabled = 1;
+
+static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%d\n", pm_async_enabled);
+}
+
+static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t n)
+{
+ unsigned long val;
+
+ if (strict_strtoul(buf, 10, &val))
+ return -EINVAL;
+
+ if (val > 1)
+ return -EINVAL;
+
+ pm_async_enabled = val;
+ return n;
+}
+
+power_attr(pm_async);
+
#ifdef CONFIG_PM_DEBUG
int pm_test_level = TEST_NONE;
@@ -208,9 +234,12 @@
#ifdef CONFIG_PM_TRACE
&pm_trace_attr.attr,
#endif
-#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG)
+#ifdef CONFIG_PM_SLEEP
+ &pm_async_attr.attr,
+#ifdef CONFIG_PM_DEBUG
&pm_test_attr.attr,
#endif
+#endif
NULL,
};