diff --git a/services/surfaceflinger/DispSync.cpp b/services/surfaceflinger/DispSync.cpp
index a342dfe..5ba387d 100644
--- a/services/surfaceflinger/DispSync.cpp
+++ b/services/surfaceflinger/DispSync.cpp
@@ -56,15 +56,17 @@
             mStop(false),
             mPeriod(0),
             mPhase(0),
+            mReferenceTime(0),
             mWakeupLatency(0) {
     }
 
     virtual ~DispSyncThread() {}
 
-    void updateModel(nsecs_t period, nsecs_t phase) {
+    void updateModel(nsecs_t period, nsecs_t phase, nsecs_t referenceTime) {
         Mutex::Autolock lock(mMutex);
         mPeriod = period;
         mPhase = phase;
+        mReferenceTime = referenceTime;
         mCond.signal();
     }
 
@@ -246,7 +248,7 @@
             ref = lastEventTime;
         }
 
-        nsecs_t phase = mPhase + listener.mPhase;
+        nsecs_t phase = mReferenceTime + mPhase + listener.mPhase;
         nsecs_t t = (((ref - phase) / mPeriod) + 1) * mPeriod + phase;
 
         if (t - listener.mLastEventTime < mPeriod / 2) {
@@ -266,6 +268,7 @@
 
     nsecs_t mPeriod;
     nsecs_t mPhase;
+    nsecs_t mReferenceTime;
     nsecs_t mWakeupLatency;
 
     Vector<EventListener> mEventListeners;
@@ -313,9 +316,11 @@
 void DispSync::reset() {
     Mutex::Autolock lock(mMutex);
 
+    mPhase = 0;
+    mReferenceTime = 0;
+    mModelUpdated = false;
     mNumResyncSamples = 0;
     mFirstResyncSample = 0;
-    mResyncReferenceTime = 0;
     mNumResyncSamplesSincePresent = 0;
     resetErrorLocked();
 }
@@ -341,12 +346,13 @@
 
     updateErrorLocked();
 
-    return mPeriod == 0 || mError > kErrorThreshold;
+    return !mModelUpdated || mError > kErrorThreshold;
 }
 
 void DispSync::beginResync() {
     Mutex::Autolock lock(mMutex);
 
+    mModelUpdated = false;
     mNumResyncSamples = 0;
 }
 
@@ -356,7 +362,8 @@
     size_t idx = (mFirstResyncSample + mNumResyncSamples) % MAX_RESYNC_SAMPLES;
     mResyncSamples[idx] = timestamp;
     if (mNumResyncSamples == 0) {
-        mResyncReferenceTime = timestamp;
+        mPhase = 0;
+        mReferenceTime = timestamp;
     }
 
     if (mNumResyncSamples < MAX_RESYNC_SAMPLES) {
@@ -380,7 +387,7 @@
         return mThread->hasAnyEventListeners();
     }
 
-    return mPeriod == 0 || mError > kErrorThreshold;
+    return !mModelUpdated || mError > kErrorThreshold;
 }
 
 void DispSync::endResync() {
@@ -409,7 +416,8 @@
     Mutex::Autolock lock(mMutex);
     mPeriod = period;
     mPhase = 0;
-    mThread->updateModel(mPeriod, mPhase);
+    mReferenceTime = 0;
+    mThread->updateModel(mPeriod, mPhase, mReferenceTime);
 }
 
 nsecs_t DispSync::getPeriod() {
@@ -434,7 +442,7 @@
         double scale = 2.0 * M_PI / double(mPeriod);
         for (size_t i = 0; i < mNumResyncSamples; i++) {
             size_t idx = (mFirstResyncSample + i) % MAX_RESYNC_SAMPLES;
-            nsecs_t sample = mResyncSamples[idx] - mResyncReferenceTime;
+            nsecs_t sample = mResyncSamples[idx] - mReferenceTime;
             double samplePhase = double(sample % mPeriod) * scale;
             sampleAvgX += cos(samplePhase);
             sampleAvgY += sin(samplePhase);
@@ -457,12 +465,13 @@
         // Artificially inflate the period if requested.
         mPeriod += mPeriod * mRefreshSkipCount;
 
-        mThread->updateModel(mPeriod, mPhase);
+        mThread->updateModel(mPeriod, mPhase, mReferenceTime);
+        mModelUpdated = true;
     }
 }
 
 void DispSync::updateErrorLocked() {
-    if (mPeriod == 0) {
+    if (!mModelUpdated) {
         return;
     }
 
@@ -474,7 +483,7 @@
     nsecs_t sqErrSum = 0;
 
     for (size_t i = 0; i < NUM_PRESENT_SAMPLES; i++) {
-        nsecs_t sample = mPresentTimes[i] - mResyncReferenceTime;
+        nsecs_t sample = mPresentTimes[i] - mReferenceTime;
         if (sample > mPhase) {
             nsecs_t sampleErr = (sample - mPhase) % period;
             if (sampleErr > period / 2) {
@@ -508,7 +517,8 @@
 nsecs_t DispSync::computeNextRefresh(int periodOffset) const {
     Mutex::Autolock lock(mMutex);
     nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
-    return (((now - mPhase) / mPeriod) + periodOffset + 1) * mPeriod + mPhase;
+    nsecs_t phase = mReferenceTime + mPhase;
+    return (((now - phase) / mPeriod) + periodOffset + 1) * mPeriod + phase;
 }
 
 void DispSync::dump(String8& result) const {