diff --git a/[refs] b/[refs]
index 4a94fd54ee63..246b3abcdf29 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: bc25cf508942c56810d4fb623ef27b56ccef7783
+refs/heads/master: c48825251cf5950da9d618144c4db6c130e6c0cd
diff --git a/trunk/include/linux/pm.h b/trunk/include/linux/pm.h
index 73c610573a74..d6dd6f612b8d 100644
--- a/trunk/include/linux/pm.h
+++ b/trunk/include/linux/pm.h
@@ -320,6 +320,15 @@ const struct dev_pm_ops name = { \
 /*
  * Use this for defining a set of PM operations to be used in all situations
  * (sustem suspend, hibernation or runtime PM).
+ * NOTE: In general, system suspend callbacks, .suspend() and .resume(), should
+ * be different from the corresponding runtime PM callbacks, .runtime_suspend(),
+ * and .runtime_resume(), because .runtime_suspend() always works on an already
+ * quiescent device, while .suspend() should assume that the device may be doing
+ * something when it is called (it should ensure that the device will be
+ * quiescent after it has returned).  Therefore it's better to point the "late"
+ * suspend and "early" resume callback pointers, .suspend_late() and
+ * .resume_early(), to the same routines as .runtime_suspend() and
+ * .runtime_resume(), respectively (and analogously for hibernation).
  */
 #define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
 const struct dev_pm_ops name = { \