diff --git a/services/surfaceflinger/tests/unittests/VSyncDispatchRealtimeTest.cpp b/services/surfaceflinger/tests/unittests/VSyncDispatchRealtimeTest.cpp
index acf852d..caac61d 100644
--- a/services/surfaceflinger/tests/unittests/VSyncDispatchRealtimeTest.cpp
+++ b/services/surfaceflinger/tests/unittests/VSyncDispatchRealtimeTest.cpp
@@ -37,7 +37,7 @@
 public:
     FixedRateIdealStubTracker() : mPeriod{toNs(3ms)} {}
 
-    void addVsyncTimestamp(nsecs_t) final {}
+    bool addVsyncTimestamp(nsecs_t) final { return true; }
 
     nsecs_t nextAnticipatedVSyncTimeFrom(nsecs_t timePoint) const final {
         auto const floor = timePoint % mPeriod;
@@ -60,7 +60,7 @@
 public:
     VRRStubTracker(nsecs_t period) : mPeriod{period} {}
 
-    void addVsyncTimestamp(nsecs_t) final {}
+    bool addVsyncTimestamp(nsecs_t) final { return true; }
 
     nsecs_t nextAnticipatedVSyncTimeFrom(nsecs_t time_point) const final {
         std::lock_guard<decltype(mMutex)> lk(mMutex);
diff --git a/services/surfaceflinger/tests/unittests/VSyncDispatchTimerQueueTest.cpp b/services/surfaceflinger/tests/unittests/VSyncDispatchTimerQueueTest.cpp
index 70c9225..3ab38e4 100644
--- a/services/surfaceflinger/tests/unittests/VSyncDispatchTimerQueueTest.cpp
+++ b/services/surfaceflinger/tests/unittests/VSyncDispatchTimerQueueTest.cpp
@@ -39,9 +39,10 @@
     MockVSyncTracker(nsecs_t period) : mPeriod{period} {
         ON_CALL(*this, nextAnticipatedVSyncTimeFrom(_))
                 .WillByDefault(Invoke(this, &MockVSyncTracker::nextVSyncTime));
+        ON_CALL(*this, addVsyncTimestamp(_)).WillByDefault(Return(true));
     }
 
-    MOCK_METHOD1(addVsyncTimestamp, void(nsecs_t));
+    MOCK_METHOD1(addVsyncTimestamp, bool(nsecs_t));
     MOCK_CONST_METHOD1(nextAnticipatedVSyncTimeFrom, nsecs_t(nsecs_t));
     MOCK_CONST_METHOD0(currentPeriod, nsecs_t());
     MOCK_METHOD1(setPeriod, void(nsecs_t));
diff --git a/services/surfaceflinger/tests/unittests/VSyncReactorTest.cpp b/services/surfaceflinger/tests/unittests/VSyncReactorTest.cpp
index ce1fafe..1de72b9 100644
--- a/services/surfaceflinger/tests/unittests/VSyncReactorTest.cpp
+++ b/services/surfaceflinger/tests/unittests/VSyncReactorTest.cpp
@@ -35,7 +35,8 @@
 
 class MockVSyncTracker : public VSyncTracker {
 public:
-    MOCK_METHOD1(addVsyncTimestamp, void(nsecs_t));
+    MockVSyncTracker() { ON_CALL(*this, addVsyncTimestamp(_)).WillByDefault(Return(true)); }
+    MOCK_METHOD1(addVsyncTimestamp, bool(nsecs_t));
     MOCK_CONST_METHOD1(nextAnticipatedVSyncTimeFrom, nsecs_t(nsecs_t));
     MOCK_CONST_METHOD0(currentPeriod, nsecs_t());
     MOCK_METHOD1(setPeriod, void(nsecs_t));
@@ -46,7 +47,9 @@
 public:
     VSyncTrackerWrapper(std::shared_ptr<VSyncTracker> const& tracker) : mTracker(tracker) {}
 
-    void addVsyncTimestamp(nsecs_t timestamp) final { mTracker->addVsyncTimestamp(timestamp); }
+    bool addVsyncTimestamp(nsecs_t timestamp) final {
+        return mTracker->addVsyncTimestamp(timestamp);
+    }
     nsecs_t nextAnticipatedVSyncTimeFrom(nsecs_t timePoint) const final {
         return mTracker->nextAnticipatedVSyncTimeFrom(timePoint);
     }
@@ -239,6 +242,22 @@
     EXPECT_FALSE(mReactor.addPresentFence(generateSignalledFenceWithTime(mDummyTime)));
 }
 
+TEST_F(VSyncReactorTest, ignoresProperlyAfterAPeriodConfirmation) {
+    bool periodFlushed = true;
+    EXPECT_CALL(*mMockTracker, addVsyncTimestamp(_)).Times(2);
+    mReactor.setIgnorePresentFences(true);
+
+    nsecs_t const newPeriod = 5000;
+    mReactor.setPeriod(newPeriod);
+
+    EXPECT_TRUE(mReactor.addResyncSample(0, &periodFlushed));
+    EXPECT_FALSE(periodFlushed);
+    EXPECT_FALSE(mReactor.addResyncSample(newPeriod, &periodFlushed));
+    EXPECT_TRUE(periodFlushed);
+
+    EXPECT_TRUE(mReactor.addPresentFence(generateSignalledFenceWithTime(0)));
+}
+
 TEST_F(VSyncReactorTest, queriesTrackerForNextRefreshNow) {
     nsecs_t const fakeTimestamp = 4839;
     EXPECT_CALL(*mMockTracker, currentPeriod()).Times(0);
@@ -330,6 +349,35 @@
     EXPECT_TRUE(periodFlushed);
 }
 
+TEST_F(VSyncReactorTest, reportedBadTimestampFromPredictorWillReactivateHwVSync) {
+    EXPECT_CALL(*mMockTracker, addVsyncTimestamp(_))
+            .WillOnce(Return(false))
+            .WillOnce(Return(true))
+            .WillOnce(Return(true));
+    EXPECT_TRUE(mReactor.addPresentFence(generateSignalledFenceWithTime(0)));
+    EXPECT_TRUE(mReactor.addPresentFence(generateSignalledFenceWithTime(0)));
+
+    nsecs_t skewyPeriod = period >> 1;
+    bool periodFlushed = false;
+    nsecs_t sampleTime = 0;
+    EXPECT_TRUE(mReactor.addResyncSample(sampleTime += skewyPeriod, &periodFlushed));
+    EXPECT_FALSE(periodFlushed);
+    EXPECT_FALSE(mReactor.addResyncSample(sampleTime += period, &periodFlushed));
+    EXPECT_FALSE(periodFlushed);
+}
+
+TEST_F(VSyncReactorTest, reportedBadTimestampFromPredictorWillReactivateHwVSyncPendingFence) {
+    EXPECT_CALL(*mMockTracker, addVsyncTimestamp(_))
+            .Times(2)
+            .WillOnce(Return(false))
+            .WillOnce(Return(true));
+
+    auto fence = generatePendingFence();
+    EXPECT_FALSE(mReactor.addPresentFence(fence));
+    signalFenceWithTime(fence, period >> 1);
+    EXPECT_TRUE(mReactor.addPresentFence(generateSignalledFenceWithTime(0)));
+}
+
 TEST_F(VSyncReactorTest, presentFenceAdditionDoesNotInterruptConfirmationProcess) {
     nsecs_t const newPeriod = 5000;
     mReactor.setPeriod(newPeriod);