Merge "Fix usage of HWC_DISPLAY_PRIMARY in vr flinger"
diff --git a/libs/vr/libvrflinger/display_service.cpp b/libs/vr/libvrflinger/display_service.cpp
index ac68a5e..a18ff1a 100644
--- a/libs/vr/libvrflinger/display_service.cpp
+++ b/libs/vr/libvrflinger/display_service.cpp
@@ -38,10 +38,12 @@
 namespace dvr {
 
 DisplayService::DisplayService(Hwc2::Composer* hidl,
+                               hwc2_display_t primary_display_id,
                                RequestDisplayCallback request_display_callback)
     : BASE("DisplayService",
            Endpoint::Create(display::DisplayProtocol::kClientPath)) {
-  hardware_composer_.Initialize(hidl, request_display_callback);
+    hardware_composer_.Initialize(
+        hidl, primary_display_id, request_display_callback);
 }
 
 bool DisplayService::IsInitialized() const {
diff --git a/libs/vr/libvrflinger/display_service.h b/libs/vr/libvrflinger/display_service.h
index 55e33ab..a3ee7bb 100644
--- a/libs/vr/libvrflinger/display_service.h
+++ b/libs/vr/libvrflinger/display_service.h
@@ -81,6 +81,7 @@
   using RequestDisplayCallback = std::function<void(bool)>;
 
   DisplayService(android::Hwc2::Composer* hidl,
+                 hwc2_display_t primary_display_id,
                  RequestDisplayCallback request_display_callback);
 
   pdx::Status<BorrowedNativeBufferHandle> OnGetGlobalBuffer(
diff --git a/libs/vr/libvrflinger/hardware_composer.cpp b/libs/vr/libvrflinger/hardware_composer.cpp
index 44be0ab..be17ecf 100644
--- a/libs/vr/libvrflinger/hardware_composer.cpp
+++ b/libs/vr/libvrflinger/hardware_composer.cpp
@@ -121,7 +121,8 @@
 }
 
 bool HardwareComposer::Initialize(
-    Hwc2::Composer* composer, RequestDisplayCallback request_display_callback) {
+    Hwc2::Composer* composer, hwc2_display_t primary_display_id,
+    RequestDisplayCallback request_display_callback) {
   if (initialized_) {
     ALOGE("HardwareComposer::Initialize: already initialized.");
     return false;
@@ -134,7 +135,7 @@
   HWC::Error error = HWC::Error::None;
 
   Hwc2::Config config;
-  error = composer->getActiveConfig(HWC_DISPLAY_PRIMARY, &config);
+  error = composer->getActiveConfig(primary_display_id, &config);
 
   if (error != HWC::Error::None) {
     ALOGE("HardwareComposer: Failed to get current display config : %d",
@@ -142,7 +143,7 @@
     return false;
   }
 
-  error = GetDisplayMetrics(composer, HWC_DISPLAY_PRIMARY, config,
+  error = GetDisplayMetrics(composer, primary_display_id, config,
                             &native_display_metrics_);
 
   if (error != HWC::Error::None) {
@@ -233,7 +234,10 @@
     composer_.reset(new Hwc2::Composer("default"));
     composer_callback_ = new ComposerCallback;
     composer_->registerCallback(composer_callback_);
+    LOG_ALWAYS_FATAL_IF(!composer_callback_->HasDisplayId(),
+        "Registered composer callback but didn't get primary display");
     Layer::SetComposer(composer_.get());
+    Layer::SetDisplayId(composer_callback_->GetDisplayId());
   } else {
     SetPowerMode(true);
   }
@@ -263,6 +267,7 @@
     composer_callback_ = nullptr;
     composer_.reset(nullptr);
     Layer::SetComposer(nullptr);
+    Layer::SetDisplayId(0);
   } else {
     SetPowerMode(false);
   }
@@ -290,7 +295,7 @@
 
 HWC::Error HardwareComposer::EnableVsync(bool enabled) {
   return composer_->setVsyncEnabled(
-      HWC_DISPLAY_PRIMARY,
+      composer_callback_->GetDisplayId(),
       (Hwc2::IComposerClient::Vsync)(enabled ? HWC2_VSYNC_ENABLE
                                              : HWC2_VSYNC_DISABLE));
 }
@@ -298,7 +303,8 @@
 HWC::Error HardwareComposer::SetPowerMode(bool active) {
   HWC::PowerMode power_mode = active ? HWC::PowerMode::On : HWC::PowerMode::Off;
   return composer_->setPowerMode(
-      HWC_DISPLAY_PRIMARY, power_mode.cast<Hwc2::IComposerClient::PowerMode>());
+      composer_callback_->GetDisplayId(),
+      power_mode.cast<Hwc2::IComposerClient::PowerMode>());
 }
 
 HWC::Error HardwareComposer::Present(hwc2_display_t display) {
@@ -419,7 +425,7 @@
     layer.Prepare();
   }
 
-  HWC::Error error = Validate(HWC_DISPLAY_PRIMARY);
+  HWC::Error error = Validate(composer_callback_->GetDisplayId());
   if (error != HWC::Error::None) {
     ALOGE("HardwareComposer::PostLayers: Validate failed: %s",
           error.to_string().c_str());
@@ -466,7 +472,7 @@
   }
 #endif
 
-  error = Present(HWC_DISPLAY_PRIMARY);
+  error = Present(composer_callback_->GetDisplayId());
   if (error != HWC::Error::None) {
     ALOGE("HardwareComposer::PostLayers: Present failed: %s",
           error.to_string().c_str());
@@ -475,8 +481,8 @@
 
   std::vector<Hwc2::Layer> out_layers;
   std::vector<int> out_fences;
-  error = composer_->getReleaseFences(HWC_DISPLAY_PRIMARY, &out_layers,
-                                      &out_fences);
+  error = composer_->getReleaseFences(composer_callback_->GetDisplayId(),
+                                      &out_layers, &out_fences);
   ALOGE_IF(error != HWC::Error::None,
            "HardwareComposer::PostLayers: Failed to get release fences: %s",
            error.to_string().c_str());
@@ -615,14 +621,6 @@
   }
 }
 
-Status<int64_t> HardwareComposer::GetVSyncTime() {
-  auto status = composer_callback_->GetVsyncTime(HWC_DISPLAY_PRIMARY);
-  ALOGE_IF(!status,
-           "HardwareComposer::GetVSyncTime: Failed to get vsync timestamp: %s",
-           status.GetErrorMessage().c_str());
-  return status;
-}
-
 // Waits for the next vsync and returns the timestamp of the vsync event. If
 // vsync already passed since the last call, returns the latest vsync timestamp
 // instead of blocking.
@@ -795,8 +793,7 @@
     // Signal all of the vsync clients. Because absolute time is used for the
     // wakeup time below, this can take a little time if necessary.
     if (vsync_callback_)
-      vsync_callback_(HWC_DISPLAY_PRIMARY, vsync_timestamp,
-                      /*frame_time_estimate*/ 0, vsync_count_);
+      vsync_callback_(vsync_timestamp, /*frame_time_estimate*/ 0, vsync_count_);
 
     {
       // Sleep until shortly before vsync.
@@ -819,7 +816,7 @@
             // If the layer config changed we need to validateDisplay() even if
             // we're going to drop the frame, to flush the Composer object's
             // internal command buffer and apply our layer changes.
-            Validate(HWC_DISPLAY_PRIMARY);
+            Validate(composer_callback_->GetDisplayId());
           }
           continue;
         }
@@ -827,7 +824,7 @@
     }
 
     {
-      auto status = GetVSyncTime();
+      auto status = composer_callback_->GetVsyncTime();
       if (!status) {
         ALOGE("HardwareComposer::PostThread: Failed to get VSYNC time: %s",
               status.GetErrorMessage().c_str());
@@ -946,10 +943,17 @@
 }
 
 Return<void> HardwareComposer::ComposerCallback::onHotplug(
-    Hwc2::Display display, IComposerCallback::Connection /*conn*/) {
-  // See if the driver supports the vsync_event node in sysfs.
-  if (display < HWC_NUM_PHYSICAL_DISPLAY_TYPES &&
-      !displays_[display].driver_vsync_event_fd) {
+    Hwc2::Display display, IComposerCallback::Connection conn) {
+  // Our first onHotplug callback is always for the primary display.
+  //
+  // Ignore any other hotplug callbacks since the primary display is never
+  // disconnected and we don't care about other displays.
+  if (!has_display_id_) {
+    LOG_ALWAYS_FATAL_IF(conn != IComposerCallback::Connection::CONNECTED,
+        "Initial onHotplug callback should be primary display connected");
+    has_display_id_ = true;
+    display_id_ = display;
+
     std::array<char, 1024> buffer;
     snprintf(buffer.data(), buffer.size(),
              "/sys/class/graphics/fb%" PRIu64 "/vsync_event", display);
@@ -958,7 +962,7 @@
           "HardwareComposer::ComposerCallback::onHotplug: Driver supports "
           "vsync_event node for display %" PRIu64,
           display);
-      displays_[display].driver_vsync_event_fd = std::move(handle);
+      driver_vsync_event_fd_ = std::move(handle);
     } else {
       ALOGI(
           "HardwareComposer::ComposerCallback::onHotplug: Driver does not "
@@ -977,36 +981,23 @@
 
 Return<void> HardwareComposer::ComposerCallback::onVsync(Hwc2::Display display,
                                                          int64_t timestamp) {
-  TRACE_FORMAT("vsync_callback|display=%" PRIu64 ";timestamp=%" PRId64 "|",
-               display, timestamp);
-  if (display < HWC_NUM_PHYSICAL_DISPLAY_TYPES) {
-    displays_[display].callback_vsync_timestamp = timestamp;
-  } else {
-    ALOGW(
-        "HardwareComposer::ComposerCallback::onVsync: Received vsync on "
-        "non-physical display: display=%" PRId64,
-        display);
+  // Ignore any onVsync callbacks for the non-primary display.
+  if (has_display_id_ && display == display_id_) {
+    TRACE_FORMAT("vsync_callback|display=%" PRIu64 ";timestamp=%" PRId64 "|",
+                 display, timestamp);
+    callback_vsync_timestamp_ = timestamp;
   }
   return Void();
 }
 
-Status<int64_t> HardwareComposer::ComposerCallback::GetVsyncTime(
-    Hwc2::Display display) {
-  if (display >= HWC_NUM_PHYSICAL_DISPLAY_TYPES) {
-    ALOGE(
-        "HardwareComposer::ComposerCallback::GetVsyncTime: Invalid physical "
-        "display requested: display=%" PRIu64,
-        display);
-    return ErrorStatus(EINVAL);
-  }
-
+Status<int64_t> HardwareComposer::ComposerCallback::GetVsyncTime() {
   // See if the driver supports direct vsync events.
-  LocalHandle& event_fd = displays_[display].driver_vsync_event_fd;
+  LocalHandle& event_fd = driver_vsync_event_fd_;
   if (!event_fd) {
     // Fall back to returning the last timestamp returned by the vsync
     // callback.
     std::lock_guard<std::mutex> autolock(vsync_mutex_);
-    return displays_[display].callback_vsync_timestamp;
+    return callback_vsync_timestamp_;
   }
 
   // When the driver supports the vsync_event sysfs node we can use it to
@@ -1056,10 +1047,11 @@
 
 Hwc2::Composer* Layer::composer_{nullptr};
 HWCDisplayMetrics Layer::display_metrics_{0, 0, {0, 0}, 0};
+hwc2_display_t Layer::display_id_{0};
 
 void Layer::Reset() {
   if (hardware_composer_layer_) {
-    composer_->destroyLayer(HWC_DISPLAY_PRIMARY, hardware_composer_layer_);
+    composer_->destroyLayer(display_id_, hardware_composer_layer_);
     hardware_composer_layer_ = 0;
   }
 
@@ -1154,17 +1146,16 @@
     pending_visibility_settings_ = false;
 
     HWC::Error error;
-    hwc2_display_t display = HWC_DISPLAY_PRIMARY;
 
     error = composer_->setLayerBlendMode(
-        display, hardware_composer_layer_,
+        display_id_, hardware_composer_layer_,
         blending_.cast<Hwc2::IComposerClient::BlendMode>());
     ALOGE_IF(error != HWC::Error::None,
              "Layer::UpdateLayerSettings: Error setting layer blend mode: %s",
              error.to_string().c_str());
 
-    error =
-        composer_->setLayerZOrder(display, hardware_composer_layer_, z_order_);
+    error = composer_->setLayerZOrder(display_id_, hardware_composer_layer_,
+                                      z_order_);
     ALOGE_IF(error != HWC::Error::None,
              "Layer::UpdateLayerSettings: Error setting z_ order: %s",
              error.to_string().c_str());
@@ -1173,36 +1164,35 @@
 
 void Layer::UpdateLayerSettings() {
   HWC::Error error;
-  hwc2_display_t display = HWC_DISPLAY_PRIMARY;
 
   UpdateVisibilitySettings();
 
   // TODO(eieio): Use surface attributes or some other mechanism to control
   // the layer display frame.
   error = composer_->setLayerDisplayFrame(
-      display, hardware_composer_layer_,
+      display_id_, hardware_composer_layer_,
       {0, 0, display_metrics_.width, display_metrics_.height});
   ALOGE_IF(error != HWC::Error::None,
            "Layer::UpdateLayerSettings: Error setting layer display frame: %s",
            error.to_string().c_str());
 
   error = composer_->setLayerVisibleRegion(
-      display, hardware_composer_layer_,
+      display_id_, hardware_composer_layer_,
       {{0, 0, display_metrics_.width, display_metrics_.height}});
   ALOGE_IF(error != HWC::Error::None,
            "Layer::UpdateLayerSettings: Error setting layer visible region: %s",
            error.to_string().c_str());
 
-  error =
-      composer_->setLayerPlaneAlpha(display, hardware_composer_layer_, 1.0f);
+  error = composer_->setLayerPlaneAlpha(display_id_, hardware_composer_layer_,
+                                        1.0f);
   ALOGE_IF(error != HWC::Error::None,
            "Layer::UpdateLayerSettings: Error setting layer plane alpha: %s",
            error.to_string().c_str());
 }
 
 void Layer::CommonLayerSetup() {
-  HWC::Error error =
-      composer_->createLayer(HWC_DISPLAY_PRIMARY, &hardware_composer_layer_);
+  HWC::Error error = composer_->createLayer(display_id_,
+                                            &hardware_composer_layer_);
   ALOGE_IF(error != HWC::Error::None,
            "Layer::CommonLayerSetup: Failed to create layer on primary "
            "display: %s",
@@ -1246,10 +1236,10 @@
     if (composition_type_ == HWC::Composition::Invalid) {
       composition_type_ = HWC::Composition::SolidColor;
       composer_->setLayerCompositionType(
-          HWC_DISPLAY_PRIMARY, hardware_composer_layer_,
+          display_id_, hardware_composer_layer_,
           composition_type_.cast<Hwc2::IComposerClient::Composition>());
       Hwc2::IComposerClient::Color layer_color = {0, 0, 0, 0};
-      composer_->setLayerColor(HWC_DISPLAY_PRIMARY, hardware_composer_layer_,
+      composer_->setLayerColor(display_id_, hardware_composer_layer_,
                                layer_color);
     } else {
       // The composition type is already set. Nothing else to do until a
@@ -1259,7 +1249,7 @@
     if (composition_type_ != target_composition_type_) {
       composition_type_ = target_composition_type_;
       composer_->setLayerCompositionType(
-          HWC_DISPLAY_PRIMARY, hardware_composer_layer_,
+          display_id_, hardware_composer_layer_,
           composition_type_.cast<Hwc2::IComposerClient::Composition>());
     }
 
@@ -1270,7 +1260,7 @@
 
     HWC::Error error{HWC::Error::None};
     error =
-        composer_->setLayerBuffer(HWC_DISPLAY_PRIMARY, hardware_composer_layer_,
+        composer_->setLayerBuffer(display_id_, hardware_composer_layer_,
                                   slot, handle, acquire_fence_.Get());
 
     ALOGE_IF(error != HWC::Error::None,
@@ -1280,7 +1270,7 @@
     if (!surface_rect_functions_applied_) {
       const float float_right = right;
       const float float_bottom = bottom;
-      error = composer_->setLayerSourceCrop(HWC_DISPLAY_PRIMARY,
+      error = composer_->setLayerSourceCrop(display_id_,
                                             hardware_composer_layer_,
                                             {0, 0, float_right, float_bottom});
 
diff --git a/libs/vr/libvrflinger/hardware_composer.h b/libs/vr/libvrflinger/hardware_composer.h
index 7010db9..9ed4b22 100644
--- a/libs/vr/libvrflinger/hardware_composer.h
+++ b/libs/vr/libvrflinger/hardware_composer.h
@@ -152,6 +152,11 @@
     display_metrics_ = display_metrics;
   }
 
+  // Sets the display id used by all Layer instances.
+  static void SetDisplayId(hwc2_display_t display_id) {
+    display_id_ = display_id;
+  }
+
  private:
   void CommonLayerSetup();
 
@@ -180,6 +185,11 @@
   // thereafter.
   static HWCDisplayMetrics display_metrics_;
 
+  // Id of the primary display. Shared by all instances of Layer. This must be
+  // set whenever the primary display id changes. This can be left unset as long
+  // as there are no instances of Layer that might need to use it.
+  static hwc2_display_t display_id_;
+
   // The hardware composer layer and metrics to use during the prepare cycle.
   hwc2_layer_t hardware_composer_layer_ = 0;
 
@@ -298,13 +308,14 @@
 class HardwareComposer {
  public:
   // Type for vsync callback.
-  using VSyncCallback = std::function<void(int, int64_t, int64_t, uint32_t)>;
+  using VSyncCallback = std::function<void(int64_t, int64_t, uint32_t)>;
   using RequestDisplayCallback = std::function<void(bool)>;
 
   HardwareComposer();
   ~HardwareComposer();
 
   bool Initialize(Hwc2::Composer* composer,
+                  hwc2_display_t primary_display_id,
                   RequestDisplayCallback request_display_callback);
 
   bool IsInitialized() const { return initialized_; }
@@ -362,16 +373,16 @@
     hardware::Return<void> onVsync(Hwc2::Display display,
                                    int64_t timestamp) override;
 
-    pdx::Status<int64_t> GetVsyncTime(Hwc2::Display display);
+    bool HasDisplayId() { return has_display_id_; }
+    hwc2_display_t GetDisplayId() { return display_id_; }
+    pdx::Status<int64_t> GetVsyncTime();
 
    private:
     std::mutex vsync_mutex_;
-
-    struct Display {
-      pdx::LocalHandle driver_vsync_event_fd;
-      int64_t callback_vsync_timestamp{0};
-    };
-    std::array<Display, HWC_NUM_PHYSICAL_DISPLAY_TYPES> displays_;
+    bool has_display_id_ = false;
+    hwc2_display_t display_id_;
+    pdx::LocalHandle driver_vsync_event_fd_;
+    int64_t callback_vsync_timestamp_{0};
   };
 
   HWC::Error Validate(hwc2_display_t display);
@@ -412,7 +423,6 @@
   // kPostThreadInterrupted.
   int ReadWaitPPState();
   pdx::Status<int64_t> WaitForVSync();
-  pdx::Status<int64_t> GetVSyncTime();
   int SleepUntil(int64_t wakeup_timestamp);
 
   // Reconfigures the layer stack if the display surfaces changed since the last
diff --git a/libs/vr/libvrflinger/include/dvr/vr_flinger.h b/libs/vr/libvrflinger/include/dvr/vr_flinger.h
index 33cbc84..c740dde 100644
--- a/libs/vr/libvrflinger/include/dvr/vr_flinger.h
+++ b/libs/vr/libvrflinger/include/dvr/vr_flinger.h
@@ -4,6 +4,12 @@
 #include <thread>
 #include <memory>
 
+#define HWC2_INCLUDE_STRINGIFICATION
+#define HWC2_USE_CPP11
+#include <hardware/hwcomposer2.h>
+#undef HWC2_INCLUDE_STRINGIFICATION
+#undef HWC2_USE_CPP11
+
 #include <pdx/service_dispatcher.h>
 #include <vr/vr_manager/vr_manager.h>
 
@@ -21,7 +27,9 @@
  public:
   using RequestDisplayCallback = std::function<void(bool)>;
   static std::unique_ptr<VrFlinger> Create(
-      Hwc2::Composer* hidl, RequestDisplayCallback request_display_callback);
+      Hwc2::Composer* hidl,
+      hwc2_display_t primary_display_id,
+      RequestDisplayCallback request_display_callback);
   ~VrFlinger();
 
   // These functions are all called on surface flinger's main thread.
@@ -35,6 +43,7 @@
  private:
   VrFlinger();
   bool Init(Hwc2::Composer* hidl,
+            hwc2_display_t primary_display_id,
             RequestDisplayCallback request_display_callback);
 
   // Needs to be a separate class for binder's ref counting
diff --git a/libs/vr/libvrflinger/vr_flinger.cpp b/libs/vr/libvrflinger/vr_flinger.cpp
index 85dc586..5e7abd7 100644
--- a/libs/vr/libvrflinger/vr_flinger.cpp
+++ b/libs/vr/libvrflinger/vr_flinger.cpp
@@ -29,9 +29,10 @@
 namespace dvr {
 
 std::unique_ptr<VrFlinger> VrFlinger::Create(
-    Hwc2::Composer* hidl, RequestDisplayCallback request_display_callback) {
+    Hwc2::Composer* hidl, hwc2_display_t primary_display_id,
+    RequestDisplayCallback request_display_callback) {
   std::unique_ptr<VrFlinger> vr_flinger(new VrFlinger);
-  if (vr_flinger->Init(hidl, request_display_callback))
+  if (vr_flinger->Init(hidl, primary_display_id, request_display_callback))
     return vr_flinger;
   else
     return nullptr;
@@ -56,6 +57,7 @@
 }
 
 bool VrFlinger::Init(Hwc2::Composer* hidl,
+                     hwc2_display_t primary_display_id,
                      RequestDisplayCallback request_display_callback) {
   if (!hidl || !request_display_callback)
     return false;
@@ -74,8 +76,8 @@
   dispatcher_ = android::pdx::ServiceDispatcher::Create();
   CHECK_ERROR(!dispatcher_, error, "Failed to create service dispatcher.");
 
-  display_service_ =
-      android::dvr::DisplayService::Create(hidl, request_display_callback);
+  display_service_ = android::dvr::DisplayService::Create(
+      hidl, primary_display_id, request_display_callback);
   CHECK_ERROR(!display_service_, error, "Failed to create display service.");
   dispatcher_->AddService(display_service_);
 
@@ -91,7 +93,7 @@
       std::bind(&android::dvr::VSyncService::VSyncEvent,
                 std::static_pointer_cast<android::dvr::VSyncService>(service),
                 std::placeholders::_1, std::placeholders::_2,
-                std::placeholders::_3, std::placeholders::_4));
+                std::placeholders::_3));
 
   dispatcher_thread_ = std::thread([this]() {
     prctl(PR_SET_NAME, reinterpret_cast<unsigned long>("VrDispatch"), 0, 0, 0);
diff --git a/libs/vr/libvrflinger/vsync_service.cpp b/libs/vr/libvrflinger/vsync_service.cpp
index fdeb899..b8d8b08 100644
--- a/libs/vr/libvrflinger/vsync_service.cpp
+++ b/libs/vr/libvrflinger/vsync_service.cpp
@@ -32,21 +32,19 @@
 
 VSyncService::~VSyncService() {}
 
-void VSyncService::VSyncEvent(int display, int64_t timestamp_ns,
+void VSyncService::VSyncEvent(int64_t timestamp_ns,
                               int64_t compositor_time_ns,
                               uint32_t vsync_count) {
   ATRACE_NAME("VSyncService::VSyncEvent");
   std::lock_guard<std::mutex> autolock(mutex_);
 
-  if (display == HWC_DISPLAY_PRIMARY) {
-    last_vsync_ = current_vsync_;
-    current_vsync_ = timestamp_ns;
-    compositor_time_ns_ = compositor_time_ns;
-    current_vsync_count_ = vsync_count;
+  last_vsync_ = current_vsync_;
+  current_vsync_ = timestamp_ns;
+  compositor_time_ns_ = compositor_time_ns;
+  current_vsync_count_ = vsync_count;
 
-    NotifyWaiters();
-    UpdateClients();
-  }
+  NotifyWaiters();
+  UpdateClients();
 }
 
 std::shared_ptr<Channel> VSyncService::OnChannelOpen(pdx::Message& message) {
diff --git a/libs/vr/libvrflinger/vsync_service.h b/libs/vr/libvrflinger/vsync_service.h
index 215948e..822f02b 100644
--- a/libs/vr/libvrflinger/vsync_service.h
+++ b/libs/vr/libvrflinger/vsync_service.h
@@ -63,9 +63,10 @@
                       const std::shared_ptr<pdx::Channel>& channel) override;
 
   // Called by the hardware composer HAL, or similar, whenever a vsync event
-  // occurs. |compositor_time_ns| is the number of ns before the next vsync when
-  // the compositor will preempt the GPU to do EDS and lens warp.
-  void VSyncEvent(int display, int64_t timestamp_ns, int64_t compositor_time_ns,
+  // occurs on the primary display. |compositor_time_ns| is the number of ns
+  // before the next vsync when the compositor will preempt the GPU to do EDS
+  // and lens warp.
+  void VSyncEvent(int64_t timestamp_ns, int64_t compositor_time_ns,
                   uint32_t vsync_count);
 
  private:
diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk
index 2a78aa5..ecee8ce 100644
--- a/services/surfaceflinger/Android.mk
+++ b/services/surfaceflinger/Android.mk
@@ -150,7 +150,7 @@
 LOCAL_32_BIT_ONLY := true
 endif
 
-LOCAL_CFLAGS += -Wall -Werror -Wunused -Wunreachable-code
+LOCAL_CFLAGS += -Wall -Werror -Wunused -Wunreachable-code -std=c++1z
 
 include $(BUILD_EXECUTABLE)
 
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index 5328a22..60b85c5 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -868,6 +868,14 @@
     result.append(mHwcDevice->dump().c_str());
 }
 
+std::optional<hwc2_display_t>
+HWComposer::getHwcDisplayId(int32_t displayId) const {
+    if (!isValidDisplay(displayId)) {
+        return {};
+    }
+    return mDisplayData[displayId].hwcDisplay->getId();
+}
+
 // ---------------------------------------------------------------------------
 
 HWComposer::DisplayData::DisplayData()
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 3b6d931..74b3a38 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -33,6 +33,7 @@
 #include <utils/Vector.h>
 
 #include <memory>
+#include <optional>
 #include <set>
 #include <vector>
 
@@ -161,6 +162,8 @@
     void dump(String8& out) const;
 
     android::Hwc2::Composer* getComposer() const { return mHwcDevice->getComposer(); }
+
+    std::optional<hwc2_display_t> getHwcDisplayId(int32_t displayId) const;
 private:
     static const int32_t VIRTUAL_DISPLAY_ID_BASE = 2;
 
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 0351b9f..cab9219 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -649,7 +649,8 @@
             postMessageAsync(message);
         };
         mVrFlinger = dvr::VrFlinger::Create(mHwc->getComposer(),
-                                            vrFlingerRequestDisplayCallback);
+                mHwc->getHwcDisplayId(HWC_DISPLAY_PRIMARY).value_or(0),
+                vrFlingerRequestDisplayCallback);
         if (!mVrFlinger) {
             ALOGE("Failed to start vrflinger");
         }
diff --git a/services/surfaceflinger/tests/fakehwc/Android.bp b/services/surfaceflinger/tests/fakehwc/Android.bp
index 212b9e7..47c4f4a 100644
--- a/services/surfaceflinger/tests/fakehwc/Android.bp
+++ b/services/surfaceflinger/tests/fakehwc/Android.bp
@@ -31,6 +31,9 @@
         "libtrace_proto",
         "libgmock"
     ],
+    cppflags: [
+        "-std=c++1z",
+    ],
     tags: ["tests"],
     test_suites: ["device-tests"]
 }
\ No newline at end of file