commit 59a60b7b4f457bba27be21006a9ee148bb7e51e0
author Huihong Luo <huisinro@google.com> Wed Mar 08 21:44:59 2023 +0000
committer Huihong Luo <huisinro@google.com> Fri Apr 14 20:37:03 2023 +0000
tree 5fb40bce68e64e667d484aebbd8ae41f7f212ad2
parent 763ee2914fc1a555ef13019ea4a2a14c17ea3678

Round up virtual display refresh rate

This semantics guarantees the virtual display will at least have the
specified refresh rate, e.g., if 60hz is requested on a 90hz display,
the virtual dislay will get a 90hz.

Bug: 266965278
Test: atest libsurfaceflinger_unittest
Change-Id: Ie7b30c5766454d0ad25cfd437f0498594c690a2e

services/surfaceflinger/DisplayDevice.cpp

diff --git a/services/surfaceflinger/DisplayDevice.cpp b/services/surfaceflinger/DisplayDevice.cpp
index 01db0cd..20f4de1 100644
--- a/services/surfaceflinger/DisplayDevice.cpp
+++ b/services/surfaceflinger/DisplayDevice.cpp
@@ -535,8 +535,8 @@
 }
 
 void DisplayDevice::adjustRefreshRate(Fps pacesetterDisplayRefreshRate) {
-    using fps_approx_ops::operator==;
-    if (mRequestedRefreshRate == 0_Hz) {
+    using fps_approx_ops::operator<=;
+    if (mRequestedRefreshRate <= 0_Hz) {
         return;
     }
 
@@ -547,7 +547,12 @@
     }
 
     unsigned divisor = static_cast<unsigned>(
-            std::round(pacesetterDisplayRefreshRate.getValue() / mRequestedRefreshRate.getValue()));
+            std::floor(pacesetterDisplayRefreshRate.getValue() / mRequestedRefreshRate.getValue()));
+    if (divisor == 0) {
+        mAdjustedRefreshRate = 0_Hz;
+        return;
+    }
+
     mAdjustedRefreshRate = pacesetterDisplayRefreshRate / divisor;
 }