diff --git a/services/surfaceflinger/Scheduler/VSyncPredictor.cpp b/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
index 04491a2..4a7cff5 100644
--- a/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
+++ b/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
@@ -89,7 +89,9 @@
 }
 
 bool VSyncPredictor::validate(nsecs_t timestamp) const {
+    SFTRACE_CALL();
     if (mLastTimestampIndex < 0 || mTimestamps.empty()) {
+        SFTRACE_INSTANT("timestamp valid (first)");
         return true;
     }
 
@@ -98,7 +100,11 @@
             (timestamp - aValidTimestamp) % idealPeriod() * kMaxPercent / idealPeriod();
     if (percent >= kOutlierTolerancePercent &&
         percent <= (kMaxPercent - kOutlierTolerancePercent)) {
-        SFTRACE_FORMAT_INSTANT("timestamp is not aligned with model");
+        SFTRACE_FORMAT_INSTANT("timestamp not aligned with model. aValidTimestamp %.2fms ago"
+                               ", timestamp %.2fms ago, idealPeriod=%.2 percent=%d",
+                               (mClock->now() - aValidTimestamp) / 1e6f,
+                               (mClock->now() - timestamp) / 1e6f,
+                               idealPeriod() / 1e6f, percent);
         return false;
     }
 
@@ -148,7 +154,10 @@
             // Add the timestamp to mTimestamps before clearing it so we could
             // update mKnownTimestamp based on the new timestamp.
             mTimestamps.push_back(timestamp);
-            clearTimestamps();
+
+            // Do not clear timelines as we don't want to break the phase while
+            // we are still learning.
+            clearTimestamps(/* clearTimelines */ false);
         } else if (!mTimestamps.empty()) {
             mKnownTimestamp =
                     std::max(timestamp, *std::max_element(mTimestamps.begin(), mTimestamps.end()));
@@ -235,7 +244,7 @@
 
     if (CC_UNLIKELY(bottom == 0)) {
         it->second = {idealPeriod(), 0};
-        clearTimestamps();
+        clearTimestamps(/* clearTimelines */ true);
         return false;
     }
 
@@ -245,7 +254,7 @@
     auto const percent = std::abs(anticipatedPeriod - idealPeriod()) * kMaxPercent / idealPeriod();
     if (percent >= kOutlierTolerancePercent) {
         it->second = {idealPeriod(), 0};
-        clearTimestamps();
+        clearTimestamps(/* clearTimelines */ true);
         return false;
     }
 
@@ -425,6 +434,9 @@
           timeout ? std::to_string(timeout->timeoutNs).c_str() : "N/A");
     std::lock_guard lock(mMutex);
 
+    // do not clear the timelines on VRR displays if we didn't change the mode
+    const bool isVrr = modePtr->getVrrConfig().has_value();
+    const bool clearTimelines = !isVrr || mDisplayModePtr->getId() != modePtr->getId();
     mDisplayModePtr = modePtr;
     mNumVsyncsForFrame = numVsyncsPerFrame(mDisplayModePtr);
     traceInt64("VSP-setPeriod", modePtr->getVsyncRate().getPeriodNsecs());
@@ -438,8 +450,10 @@
         mRateMap[idealPeriod()] = {idealPeriod(), 0};
     }
 
-    mTimelines.clear();
-    clearTimestamps();
+    if (clearTimelines) {
+      mTimelines.clear();
+    }
+    clearTimestamps(clearTimelines);
 }
 
 Duration VSyncPredictor::ensureMinFrameDurationIsKept(TimePoint expectedPresentTime,
@@ -556,15 +570,19 @@
     return mRateMap.find(idealPeriod())->second;
 }
 
-void VSyncPredictor::clearTimestamps() {
-    SFTRACE_CALL();
+void VSyncPredictor::clearTimestamps(bool clearTimelines) {
+    SFTRACE_FORMAT("%s: clearTimelines=%d", __func__, clearTimelines);
 
     if (!mTimestamps.empty()) {
         auto const maxRb = *std::max_element(mTimestamps.begin(), mTimestamps.end());
         if (mKnownTimestamp) {
             mKnownTimestamp = std::max(*mKnownTimestamp, maxRb);
+            SFTRACE_FORMAT_INSTANT("mKnownTimestamp was %.2fms ago",
+                               (mClock->now() - *mKnownTimestamp) / 1e6f);
         } else {
             mKnownTimestamp = maxRb;
+            SFTRACE_FORMAT_INSTANT("mKnownTimestamp (maxRb) was %.2fms ago",
+                               (mClock->now() - *mKnownTimestamp) / 1e6f);
         }
 
         mTimestamps.clear();
@@ -575,7 +593,7 @@
     if (mTimelines.empty()) {
         mLastCommittedVsync = TimePoint::fromNs(0);
         mTimelines.emplace_back(mLastCommittedVsync, mIdealPeriod, mRenderRateOpt);
-    } else {
+    } else if (clearTimelines) {
         while (mTimelines.size() > 1) {
             mTimelines.pop_front();
         }
@@ -596,9 +614,10 @@
 }
 
 void VSyncPredictor::resetModel() {
+    SFTRACE_CALL();
     std::lock_guard lock(mMutex);
     mRateMap[idealPeriod()] = {idealPeriod(), 0};
-    clearTimestamps();
+    clearTimestamps(/* clearTimelines */ true);
 }
 
 void VSyncPredictor::dump(std::string& result) const {
diff --git a/services/surfaceflinger/Scheduler/VSyncPredictor.h b/services/surfaceflinger/Scheduler/VSyncPredictor.h
index 6c8a2f2..2df3d04 100644
--- a/services/surfaceflinger/Scheduler/VSyncPredictor.h
+++ b/services/surfaceflinger/Scheduler/VSyncPredictor.h
@@ -127,7 +127,7 @@
 
     VSyncPredictor(VSyncPredictor const&) = delete;
     VSyncPredictor& operator=(VSyncPredictor const&) = delete;
-    void clearTimestamps() REQUIRES(mMutex);
+    void clearTimestamps(bool clearTimelines) REQUIRES(mMutex);
 
     const std::unique_ptr<Clock> mClock;
     const PhysicalDisplayId mId;
diff --git a/services/surfaceflinger/Scheduler/VSyncReactor.cpp b/services/surfaceflinger/Scheduler/VSyncReactor.cpp
index 2455822..b974cd2 100644
--- a/services/surfaceflinger/Scheduler/VSyncReactor.cpp
+++ b/services/surfaceflinger/Scheduler/VSyncReactor.cpp
@@ -140,7 +140,9 @@
     std::lock_guard lock(mMutex);
     mLastHwVsync.reset();
 
-    if (!mSupportKernelIdleTimer && mTracker.isCurrentMode(modePtr) && !force) {
+    // kernel idle timer is not applicable for VRR
+    const bool supportKernelIdleTimer = mSupportKernelIdleTimer && !modePtr->getVrrConfig();
+    if (!supportKernelIdleTimer && mTracker.isCurrentMode(modePtr) && !force) {
         endPeriodTransition();
         setIgnorePresentFencesInternal(false);
         mMoreSamplesNeeded = false;