commit 241d0eed73c96288dd499697c15a1e3eabaad955
author Kevin DuBois <kevindubois@google.com> Fri Jun 26 17:00:15 2020 -0700
committer Kevin DuBois <kevindubois@google.com> Mon Jun 29 11:59:01 2020 -0700
tree 61e44998e4da897b84b2d2485a6d901f0baa5c25
parent b9adcf3bf476d7b2b529a7c21a402590480d4fdd

SF: update VSP timebase on error condition

When an vsync timestamp is recorded that is anonmolous to the currently
recorded timestamp ringbuffer, update the timebase for synthetic
calculations.

Test: 2 new unit tests
Test: visual spot checking interactions on pixel4 device
Test: uibench a/b anti-regression
Test: dogfood with patch based one recent rvc build.
Fixes: 159882858
Change-Id: Ie201cd593a54586d9b1f488c6d2ca44178d75cf1

services/surfaceflinger/Scheduler/VSyncPredictor.cpp

diff --git a/services/surfaceflinger/Scheduler/VSyncPredictor.cpp b/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
index a3cb772..ab5773d 100644
--- a/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
+++ b/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
@@ -77,7 +77,14 @@
     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::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;
     }