Merge "SF: update VSP timebase on error condition" into rvc-dev am: 9b2526e50d

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/native/+/12014614

Change-Id: Ib53447f0ed40505b743b7a107bbb1f54b0c63370

2 files changed, 47 insertions, 2 deletions

diff --git a/services/surfaceflinger/Scheduler/VSyncPredictor.cpp b/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
index a3cb7725a7..ab5773dc09 100644
--- a/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
+++ b/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
@@ -77,7 +77,14 @@ bool VSyncPredictor::addVsyncTimestamp(nsecs_t timestamp) {
     std::lock_guard<std::mutex> lk(mMutex);
 
     if (!validate(timestamp)) {
-        ALOGV("timestamp was too far off the last known timestamp");
+        // VSR could elect to ignore the incongruent timestamp or resetModel(). If ts is ignored,
+        // don't insert this ts into mTimestamps ringbuffer.
+        if (!mTimestamps.empty()) {
+            mKnownTimestamp =
+                    std::max(timestamp, *std::max_element(mTimestamps.begin(), mTimestamps.end()));
+        } else {
+            mKnownTimestamp = timestamp;
+        }
         return false;
     }
 
@@ -236,7 +243,13 @@ void VSyncPredictor::setPeriod(nsecs_t period) {
 
 void VSyncPredictor::clearTimestamps() {
     if (!mTimestamps.empty()) {
-        mKnownTimestamp = *std::max_element(mTimestamps.begin(), mTimestamps.end());
+        auto const maxRb = *std::max_element(mTimestamps.begin(), mTimestamps.end());
+        if (mKnownTimestamp) {
+            mKnownTimestamp = std::max(*mKnownTimestamp, maxRb);
+        } else {
+            mKnownTimestamp = maxRb;
+        }
+
         mTimestamps.clear();
         mLastTimestampIndex = 0;
     }
diff --git a/services/surfaceflinger/tests/unittests/VSyncPredictorTest.cpp b/services/surfaceflinger/tests/unittests/VSyncPredictorTest.cpp
index bf2a889c89..fc39235a93 100644
--- a/services/surfaceflinger/tests/unittests/VSyncPredictorTest.cpp
+++ b/services/surfaceflinger/tests/unittests/VSyncPredictorTest.cpp
@@ -124,6 +124,38 @@ TEST_F(VSyncPredictorTest, uponNotifiedOfInaccuracyUsesSynthetic) {
     EXPECT_THAT(tracker.nextAnticipatedVSyncTimeFrom(mNow), Eq(mNow + changedPeriod));
 }
 
+// b/159882858
+TEST_F(VSyncPredictorTest, updatesTimebaseForSyntheticAfterIdleTime) {
+    for (auto i = 0u; i < kMinimumSamplesForPrediction; i++) {
+        EXPECT_TRUE(tracker.addVsyncTimestamp(mNow += mPeriod));
+    }
+
+    EXPECT_THAT(tracker.nextAnticipatedVSyncTimeFrom(mNow), Eq(mNow + mPeriod));
+
+    auto const halfPeriod = mPeriod >> 2;
+    nsecs_t relativelyLongGapWithDrift = mPeriod * 100 + halfPeriod;
+
+    EXPECT_FALSE(tracker.addVsyncTimestamp(mNow += relativelyLongGapWithDrift));
+
+    tracker.resetModel();
+    EXPECT_THAT(tracker.nextAnticipatedVSyncTimeFrom(mNow), Eq(mNow + mPeriod));
+}
+
+TEST_F(VSyncPredictorTest, uponBadVsyncWillSwitchToSyntheticWhileRecalibrating) {
+    auto const slightlyMorePeriod = mPeriod + 10;
+    for (auto i = 0u; i < kMinimumSamplesForPrediction; i++) {
+        EXPECT_TRUE(tracker.addVsyncTimestamp(mNow += slightlyMorePeriod));
+    }
+
+    EXPECT_THAT(tracker.nextAnticipatedVSyncTimeFrom(mNow), Eq(mNow + slightlyMorePeriod));
+
+    auto const halfPeriod = mPeriod >> 2;
+    EXPECT_FALSE(tracker.addVsyncTimestamp(mNow += halfPeriod));
+
+    tracker.resetModel();
+    EXPECT_THAT(tracker.nextAnticipatedVSyncTimeFrom(mNow), Eq(mNow + mPeriod));
+}
+
 TEST_F(VSyncPredictorTest, adaptsToFenceTimelines_60hzHighVariance) {
     // these are precomputed simulated 16.6s vsyncs with uniform distribution +/- 1.6ms error
     std::vector<nsecs_t> const simulatedVsyncs{