commit 33121b799af86e837114c524428ff9ac89a0f7bc
author Drew Davenport <ddavenport@google.com> Fri Dec 13 14:59:35 2024 -0700
committer Drew Davenport <ddavenport@google.com> Mon Dec 16 17:53:16 2024 -0700
tree f400a7ef4fca480cb981acb100ac8b7090d5baf2
parent d387c849400891fdd34752f5fc9d515dad0f384a

drm_hwcomposer: Move vsync tracking into VSyncWorker

Track the timestamp of the last vsync event in VSyncWorker, and provide
an interface for HwcDisplay to enable/disable tracking, and to query the
most recent timestamp.

Moving this into VSyncWorker avoids the need for the VSyncWorker thread
to acquire the global lock.

Change-Id: Ib79d9a6dc5e0f7d6a36ca01dbcda5434a0f582a4
Signed-off-by: Drew Davenport <ddavenport@google.com>

hwc2_device/HwcDisplay.cpp

diff --git a/hwc2_device/HwcDisplay.cpp b/hwc2_device/HwcDisplay.cpp
index 2260e36..8d6b0a3 100644
--- a/hwc2_device/HwcDisplay.cpp
+++ b/hwc2_device/HwcDisplay.cpp
@@ -265,8 +265,7 @@
   staged_mode_config_id_ = config;
 
   // Enable vsync events until the mode has been applied.
-  last_vsync_ts_ = 0;
-  vsync_tracking_en_ = true;
+  vsync_worker_->SetVsyncTimestampTracking(true);
   vsync_worker_->VSyncControl(true);
 
   return ConfigError::kNone;
@@ -324,10 +323,7 @@
               GetDisplayVsyncPeriod(&period_ns);
               hwc_->SendVsyncEventToClient(handle_, timestamp, period_ns);
             }
-            if (vsync_tracking_en_) {
-              last_vsync_ts_ = timestamp;
-            }
-            if (!vsync_event_en_ && !vsync_tracking_en_) {
+            if (!vsync_event_en_) {
               vsync_worker_->VSyncControl(false);
             }
           },
@@ -776,10 +772,12 @@
   if (new_vsync_period_ns) {
     vsync_worker_->SetVsyncPeriodNs(new_vsync_period_ns.value());
     staged_mode_config_id_.reset();
-    vsync_tracking_en_ = false;
-    if (last_vsync_ts_ != 0) {
+
+    vsync_worker_->SetVsyncTimestampTracking(false);
+    uint32_t last_vsync_ts = vsync_worker_->GetLastVsyncTimestamp();
+    if (last_vsync_ts != 0) {
       hwc_->SendVsyncPeriodTimingChangedEventToClient(handle_,
-                                                      last_vsync_ts_ +
+                                                      last_vsync_ts +
                                                           prev_vperiod_ns);
     }
   }
@@ -1167,8 +1165,7 @@
   outTimeline->newVsyncAppliedTimeNanos = vsyncPeriodChangeConstraints
                                               ->desiredTimeNanos;
 
-  last_vsync_ts_ = 0;
-  vsync_tracking_en_ = true;
+  vsync_worker_->SetVsyncTimestampTracking(true);
   vsync_worker_->VSyncControl(true);
 
   return HWC2::Error::None;