commit f1db8031e211780abde8678d67beae19316e3c61
author Ady Abraham <adyabr@google.com> Fri Mar 24 17:52:34 2023 -0700
committer Ady Abraham <adyabr@google.com> Tue Mar 28 15:51:43 2023 -0700
tree 68999f53ee4707b9813c10201e053cc5af5f9130
parent afbd372c3e21af5eb3aafd37146d73f0c8addda3

SF: avoid skipping waiting for the earliest time to present

When the next expected presentation time is not allocated for
the previous frame, SF needs to wait before submitting it to HWC
to prevent early presentation.

Bug: 273419557
Test: tested by partner
Test: atest ASurfaceControlTest
Change-Id: Ia83755bbc71968369fd9176944b9a85135d8a04a

services/surfaceflinger/DisplayHardware/HWComposer.cpp

diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index 28148ac..f350eba 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -395,8 +395,8 @@
 
 status_t HWComposer::getDeviceCompositionChanges(
         HalDisplayId displayId, bool frameUsesClientComposition,
-        std::chrono::steady_clock::time_point earliestPresentTime,
-        const std::shared_ptr<FenceTime>& previousPresentFence, nsecs_t expectedPresentTime,
+        std::optional<std::chrono::steady_clock::time_point> earliestPresentTime,
+        nsecs_t expectedPresentTime,
         std::optional<android::HWComposer::DeviceRequestedChanges>* outChanges) {
     ATRACE_CALL();
 
@@ -426,14 +426,13 @@
 
         // If composer supports getting the expected present time, we can skip
         // as composer will make sure to prevent early presentation
-        if (mComposer->isSupported(Hwc2::Composer::OptionalFeature::ExpectedPresentTime)) {
+        if (!earliestPresentTime) {
             return true;
         }
 
         // composer doesn't support getting the expected present time. We can only
         // skip validate if we know that we are not going to present early.
-        return std::chrono::steady_clock::now() >= earliestPresentTime ||
-                previousPresentFence->getSignalTime() == Fence::SIGNAL_TIME_PENDING;
+        return std::chrono::steady_clock::now() >= *earliestPresentTime;
     }();
 
     displayData.validateWasSkipped = false;
@@ -508,8 +507,8 @@
 }
 
 status_t HWComposer::presentAndGetReleaseFences(
-        HalDisplayId displayId, std::chrono::steady_clock::time_point earliestPresentTime,
-        const std::shared_ptr<FenceTime>& previousPresentFence) {
+        HalDisplayId displayId,
+        std::optional<std::chrono::steady_clock::time_point> earliestPresentTime) {
     ATRACE_CALL();
 
     RETURN_IF_INVALID_DISPLAY(displayId, BAD_INDEX);
@@ -525,13 +524,9 @@
         return NO_ERROR;
     }
 
-    const bool waitForEarliestPresent =
-            !mComposer->isSupported(Hwc2::Composer::OptionalFeature::ExpectedPresentTime) &&
-            previousPresentFence->getSignalTime() != Fence::SIGNAL_TIME_PENDING;
-
-    if (waitForEarliestPresent) {
+    if (earliestPresentTime) {
         ATRACE_NAME("wait for earliest present time");
-        std::this_thread::sleep_until(earliestPresentTime);
+        std::this_thread::sleep_until(*earliestPresentTime);
     }
 
     auto error = hwcDisplay->present(&displayData.lastPresentFence);