1 files changed, 25 insertions, 12 deletions

diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index aeaa7f846821..6a8fad82a3ad 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/pm_qos_params.c
@@ -53,11 +53,17 @@ enum pm_qos_type {
         PM_QOS_MIN              /* return the smallest value */
 };
 
+/*
+ * Note: The lockless read path depends on the CPU accessing
+ * target_value atomically.  Atomic access is only guaranteed on all CPU
+ * types linux supports for 32 bit quantites
+ */
 struct pm_qos_object {
         struct plist_head requests;
         struct blocking_notifier_head *notifiers;
         struct miscdevice pm_qos_power_miscdev;
         char *name;
+        s32 target_value;       /* Do not change to 64 bit */
         s32 default_value;
         enum pm_qos_type type;
 };
@@ -70,7 +76,8 @@ static struct pm_qos_object cpu_dma_pm_qos = {
         .requests = PLIST_HEAD_INIT(cpu_dma_pm_qos.requests, pm_qos_lock),
         .notifiers = &cpu_dma_lat_notifier,
         .name = "cpu_dma_latency",
-        .default_value = 2000 * USEC_PER_SEC,
+        .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
+        .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
         .type = PM_QOS_MIN,
 };
 
@@ -79,7 +86,8 @@ static struct pm_qos_object network_lat_pm_qos = {
         .requests = PLIST_HEAD_INIT(network_lat_pm_qos.requests, pm_qos_lock),
         .notifiers = &network_lat_notifier,
         .name = "network_latency",
-        .default_value = 2000 * USEC_PER_SEC,
+        .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
+        .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
         .type = PM_QOS_MIN
 };
 
@@ -89,7 +97,8 @@ static struct pm_qos_object network_throughput_pm_qos = {
         .requests = PLIST_HEAD_INIT(network_throughput_pm_qos.requests, pm_qos_lock),
         .notifiers = &network_throughput_notifier,
         .name = "network_throughput",
-        .default_value = 0,
+        .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
+        .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
         .type = PM_QOS_MAX,
 };
 
@@ -132,6 +141,16 @@ static inline int pm_qos_get_value(struct pm_qos_object *o)
         }
 }
 
+static inline s32 pm_qos_read_value(struct pm_qos_object *o)
+{
+        return o->target_value;
+}
+
+static inline void pm_qos_set_value(struct pm_qos_object *o, s32 value)
+{
+        o->target_value = value;
+}
+
 static void update_target(struct pm_qos_object *o, struct plist_node *node,
                           int del, int value)
 {
@@ -156,6 +175,7 @@ static void update_target(struct pm_qos_object *o, struct plist_node *node,
                 plist_add(node, &o->requests);
         }
         curr_value = pm_qos_get_value(o);
+        pm_qos_set_value(o, curr_value);
         spin_unlock_irqrestore(&pm_qos_lock, flags);
 
         if (prev_value != curr_value)
@@ -190,18 +210,11 @@ static int find_pm_qos_object_by_minor(int minor)
  * pm_qos_request - returns current system wide qos expectation
  * @pm_qos_class: identification of which qos value is requested
  *
- * This function returns the current target value in an atomic manner.
+ * This function returns the current target value.
  */
 int pm_qos_request(int pm_qos_class)
 {
-        unsigned long flags;
-        int value;
-
-        spin_lock_irqsave(&pm_qos_lock, flags);
-        value = pm_qos_get_value(pm_qos_array[pm_qos_class]);
-        spin_unlock_irqrestore(&pm_qos_lock, flags);
-
-        return value;
+        return pm_qos_read_value(pm_qos_array[pm_qos_class]);
 }
 EXPORT_SYMBOL_GPL(pm_qos_request);