diff --git a/libhwcomposer/hwc.cpp b/libhwcomposer/hwc.cpp
index 2b34be7..205e5e7 100644
--- a/libhwcomposer/hwc.cpp
+++ b/libhwcomposer/hwc.cpp
@@ -36,6 +36,7 @@
 #include "hwc_extonly.h"
 #include "qcom_ui.h"
 
+#define VSYNC_DEBUG 0
 using namespace qhwc;
 
 static int hwc_device_open(const struct hw_module_t* module,
@@ -130,19 +131,46 @@ static int hwc_eventControl(struct hwc_composer_device* dev,
                              int event, int value)
 {
     int ret = 0;
+    static int prev_value, temp;
+
     hwc_context_t* ctx = (hwc_context_t*)(dev);
     private_module_t* m = reinterpret_cast<private_module_t*>(
                 ctx->mFbDev->common.module);
     switch(event) {
 #ifndef NO_HW_VSYNC
         case HWC_EVENT_VSYNC:
+            if (value == prev_value){
+                //TODO see why HWC gets repeated events
+                ALOGD_IF(VSYNC_DEBUG, "%s - VSYNC is already %s",
+                        __FUNCTION__, (value)?"ENABLED":"DISABLED");
+            }
+            temp = ctx->vstate.enable;
             if(ioctl(m->framebuffer->fd, MSMFB_OVERLAY_VSYNC_CTRL, &value) < 0)
                 ret = -errno;
 
-            if(ctx->mExtDisplay->isHDMIConfigured() &&
-                 (ctx->mExtDisplay->getExternalDisplay()==EXTERN_DISPLAY_FB1)) {
-                ret = ctx->mExtDisplay->enableHDMIVsync(value);
+            /* vsync state change logic */
+            if (value == 1) {
+                //unblock vsync thread
+                pthread_mutex_lock(&ctx->vstate.lock);
+                ctx->vstate.enable = true;
+                pthread_cond_signal(&ctx->vstate.cond);
+                pthread_mutex_unlock(&ctx->vstate.lock);
             }
+            if (value == 0 && temp) {
+                //vsync thread will block
+                pthread_mutex_lock(&ctx->vstate.lock);
+                ctx->vstate.enable = false;
+                pthread_mutex_unlock(&ctx->vstate.lock);
+            }
+            ALOGD_IF (VSYNC_DEBUG, "VSYNC state changed from %s to %s",
+              (prev_value)?"ENABLED":"DISABLED", (value)?"ENABLED":"DISABLED");
+            prev_value = value;
+            /* vsync state change logic - end*/
+
+             if(ctx->mExtDisplay->isHDMIConfigured() &&
+                (ctx->mExtDisplay->getExternalDisplay()==EXTERN_DISPLAY_FB1)) {
+                ret = ctx->mExtDisplay->enableHDMIVsync(value);
+             }
            break;
 #endif
        case HWC_EVENT_ORIENTATION:
diff --git a/libhwcomposer/hwc_utils.cpp b/libhwcomposer/hwc_utils.cpp
index c952a46..ac6e428 100644
--- a/libhwcomposer/hwc_utils.cpp
+++ b/libhwcomposer/hwc_utils.cpp
@@ -66,6 +66,10 @@ void initContext(hwc_context_t *ctx)
     property_get("debug.hwc.dynThreshold", value, "2");
     ctx->dynThreshold = atof(value);
 
+    pthread_mutex_init(&(ctx->vstate.lock), NULL);
+    pthread_cond_init(&(ctx->vstate.cond), NULL);
+    ctx->vstate.enable = false;
+
     ALOGI("Initializing Qualcomm Hardware Composer");
     ALOGI("MDP version: %d", ctx->mMDP.version);
     ALOGI("DYN composition threshold : %f", ctx->dynThreshold);
@@ -98,6 +102,8 @@ void closeContext(hwc_context_t *ctx)
         ctx->mExtDisplay = NULL;
     }
 
+    pthread_mutex_destroy(&(ctx->vstate.lock));
+    pthread_cond_destroy(&(ctx->vstate.cond));
 
     free(const_cast<hwc_methods_t *>(ctx->device.methods));
 
diff --git a/libhwcomposer/hwc_utils.h b/libhwcomposer/hwc_utils.h
index 774810f..fa1cdf0 100644
--- a/libhwcomposer/hwc_utils.h
+++ b/libhwcomposer/hwc_utils.h
@@ -133,6 +133,12 @@ inline void getLayerResolution(const hwc_layer_t* layer,
 }
 }; //qhwc namespace
 
+struct vsync_state {
+    pthread_mutex_t lock;
+    pthread_cond_t  cond;
+    bool enable;
+};
+
 // -----------------------------------------------------------------------------
 // HWC context
 // This structure contains overall state
@@ -164,6 +170,9 @@ struct hwc_context_t {
 
     qhwc::MDPInfo mMDP;
 
+    //Vsync
+    struct vsync_state vstate;
+
 };
 
 #endif //HWC_UTILS_H
diff --git a/libhwcomposer/hwc_vsync.cpp b/libhwcomposer/hwc_vsync.cpp
index 4e4eb44..cc86312 100644
--- a/libhwcomposer/hwc_vsync.cpp
+++ b/libhwcomposer/hwc_vsync.cpp
@@ -42,7 +42,8 @@ static void *vsync_loop(void *param)
 
     char thread_name[64] = "hwcVsyncThread";
     prctl(PR_SET_NAME, (unsigned long) &thread_name, 0, 0, 0);
-    setpriority(PRIO_PROCESS, 0, HAL_PRIORITY_URGENT_DISPLAY);
+    setpriority(PRIO_PROCESS, 0, 
+                HAL_PRIORITY_URGENT_DISPLAY + ANDROID_PRIORITY_MORE_FAVORABLE);
 
     static char vdata[PAGE_SIZE];
 
@@ -51,12 +52,17 @@ static void *vsync_loop(void *param)
     bool fb1_vsync = false;
 
     /* Currently read vsync timestamp from drivers
-    VSYNC=41800875994
+       e.g. VSYNC=41800875994
     */
 
     hwc_procs* proc = (hwc_procs*)ctx->device.reserved_proc[0];
 
     do {
+        pthread_mutex_lock(&ctx->vstate.lock);
+        if(ctx->vstate.enable == false) {
+          pthread_cond_wait(&ctx->vstate.cond, &ctx->vstate.lock);
+        }
+        pthread_mutex_unlock(&ctx->vstate.lock);
 
        int hdmiconnected = ctx->mExtDisplay->getExternalDisplay();
 
@@ -78,15 +84,15 @@ static void *vsync_loop(void *param)
            ALOGE ("FATAL:%s:not able to open file:%s, %s",  __FUNCTION__,
                  (fb1_vsync) ? vsync_timestamp_fb1 : vsync_timestamp_fb0,
                                                          strerror(errno));
-         return NULL;
+           return NULL;
        }
-
        // Open success - read now
        len = read(fd_timestamp, vdata, PAGE_SIZE);
        if (len < 0){
            ALOGE ("FATAL:%s:not able to read file:%s, %s", __FUNCTION__,
                 (fb1_vsync) ? vsync_timestamp_fb1 : vsync_timestamp_fb0,
                                                         strerror(errno));
+           fd_timestamp = -1;
            return NULL;
        }