2 files changed, 25 insertions, 26 deletions

diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
index 643b055ed3c..8f049103708 100644
--- a/drivers/devfreq/Kconfig
+++ b/drivers/devfreq/Kconfig
@@ -1,36 +1,29 @@
-config ARCH_HAS_DEVFREQ
-        bool
-        depends on ARCH_HAS_OPP
-        help
-          Denotes that the architecture supports DEVFREQ. If the architecture
-          supports multiple OPP entries per device and the frequency of the
-          devices with OPPs may be altered dynamically, the architecture
-          supports DEVFREQ.
-
 menuconfig PM_DEVFREQ
         bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"
-        depends on PM_OPP && ARCH_HAS_DEVFREQ
         help
-          With OPP support, a device may have a list of frequencies and
-          voltages available. DEVFREQ, a generic DVFS framework can be
-          registered for a device with OPP support in order to let the
-          governor provided to DEVFREQ choose an operating frequency
-          based on the OPP's list and the policy given with DEVFREQ.
+          A device may have a list of frequencies and voltages available.
+          devfreq, a generic DVFS framework can be registered for a device
+          in order to let the governor provided to devfreq choose an
+          operating frequency based on the device driver's policy.
 
-          Each device may have its own governor and policy. DEVFREQ can
+          Each device may have its own governor and policy. Devfreq can
           reevaluate the device state periodically and/or based on the
-          OPP list changes (each frequency/voltage pair in OPP may be
-          disabled or enabled).
+          notification to "nb", a notifier block, of devfreq.
 
-          Like some CPUs with CPUFREQ, a device may have multiple clocks.
+          Like some CPUs with CPUfreq, a device may have multiple clocks.
           However, because the clock frequencies of a single device are
-          determined by the single device's state, an instance of DEVFREQ
+          determined by the single device's state, an instance of devfreq
           is attached to a single device and returns a "representative"
-          clock frequency from the OPP of the device, which is also attached
-          to a device by 1-to-1. The device registering DEVFREQ takes the
-          responsiblity to "interpret" the frequency listed in OPP and
+          clock frequency of the device, which is also attached
+          to a device by 1-to-1. The device registering devfreq takes the
+          responsiblity to "interpret" the representative frequency and
           to set its every clock accordingly with the "target" callback
-          given to DEVFREQ.
+          given to devfreq.
+
+          When OPP is used with the devfreq device, it is recommended to
+          register devfreq's nb to the OPP's notifier head.  If OPP is
+          used with the devfreq device, you may use OPP helper
+          functions defined in devfreq.h.
 
 if PM_DEVFREQ
 
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 5d15b812377..59d24e9cb8c 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -15,7 +15,9 @@
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/init.h>
+#include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/stat.h>
 #include <linux/opp.h>
 #include <linux/devfreq.h>
 #include <linux/workqueue.h>
@@ -416,10 +418,14 @@ out:
  */
 int devfreq_remove_device(struct devfreq *devfreq)
 {
+        bool central_polling;
+
         if (!devfreq)
                 return -EINVAL;
 
-        if (!devfreq->governor->no_central_polling) {
+        central_polling = !devfreq->governor->no_central_polling;
+
+        if (central_polling) {
                 mutex_lock(&devfreq_list_lock);
                 while (wait_remove_device == devfreq) {
                         mutex_unlock(&devfreq_list_lock);
@@ -431,7 +437,7 @@ int devfreq_remove_device(struct devfreq *devfreq)
         mutex_lock(&devfreq->lock);
         _remove_devfreq(devfreq, false); /* it unlocks devfreq->lock */
 
-        if (!devfreq->governor->no_central_polling)
+        if (central_polling)
                 mutex_unlock(&devfreq_list_lock);
 
         return 0;