drm_hwcomposer: Remove HWC2 usage for Present Add HwcDisplay::PresentStagedComposition to commit the changes that have been previously validated through ValidateStagedComposition. Drop usage of legacy HWC2 api in ComposerClient.cpp for DisplayCommand present commands. Change-Id: I0b7fcd4b664bf707f468cd40b1fefdfdd963f7f7 Signed-off-by: Drew Davenport <ddavenport@google.com>

diff --git a/hwc2_device/HwcDisplay.cpp b/hwc2_device/HwcDisplay.cpp
index 9fbd6b9..c0fc3c5 100644
--- a/hwc2_device/HwcDisplay.cpp
+++ b/hwc2_device/HwcDisplay.cpp

@@ -401,6 +401,29 @@
   return changed_layers;
 }
 
+auto HwcDisplay::AcceptValidatedComposition() -> void {
+  for (std::pair<const hwc2_layer_t, HwcLayer> &l : layers_) {
+    l.second.AcceptTypeChange();
+  }
+}
+
+auto HwcDisplay::PresentStagedComposition(
+    int32_t *out_present_fence, std::vector<ReleaseFence> *out_release_fences)
+    -> HWC2::Error {
+  auto error = PresentDisplay(out_present_fence);
+  if (error != HWC2::Error::None || *out_present_fence == -1) {
+    return error;
+  }
+
+  for (auto &l : layers_) {
+    if (!l.second.GetPriorBufferScanOutFlag() || !present_fence_) {
+      continue;
+    }
+    out_release_fences->emplace_back(l.first, DupFd(present_fence_));
+  }
+  return error;
+}
+
 void HwcDisplay::SetPipeline(std::shared_ptr<DrmDisplayPipeline> pipeline) {
   Deinit();
 

diff --git a/hwc2_device/HwcDisplay.h b/hwc2_device/HwcDisplay.h
index 9c113fd..8dc059c 100644
--- a/hwc2_device/HwcDisplay.h
+++ b/hwc2_device/HwcDisplay.h

@@ -95,6 +95,17 @@
   using ChangedLayer = std::pair<hwc2_layer_t, HWC2::Composition>;
   auto ValidateStagedComposition() -> std::vector<ChangedLayer>;
 
+  // Mark previously validated properties as ready to present.
+  auto AcceptValidatedComposition() -> void;
+
+  // Present previously staged properties, and return fences to indicate when
+  // the new content has been presented, and when the previous buffers have
+  // been released.
+  using ReleaseFence = std::pair<hwc2_layer_t, int32_t>;
+  auto PresentStagedComposition(int32_t *out_present_fence,
+                                std::vector<ReleaseFence> *out_release_fences)
+      -> HWC2::Error;
+
   // HWC2 Hooks - these should not be used outside of the hwc2 device.
   HWC2::Error AcceptDisplayChanges();
   HWC2::Error CreateLayer(hwc2_layer_t *layer);

diff --git a/hwc3/ComposerClient.cpp b/hwc3/ComposerClient.cpp
index d084ef0..90043d8 100644
--- a/hwc3/ComposerClient.cpp
+++ b/hwc3/ComposerClient.cpp

@@ -456,51 +456,6 @@
   return ToBinderStatus(err);
 }
 
-hwc3::Error ComposerClient::PresentDisplayInternal(
-    uint64_t display_id, ::android::base::unique_fd& out_display_fence,
-    std::unordered_map<int64_t, ::android::base::unique_fd>&
-        out_release_fences) {
-  DEBUG_FUNC();
-  auto* display = GetDisplay(display_id);
-  if (display == nullptr) {
-    return hwc3::Error::kBadDisplay;
-  }
-
-  if (composer_resources_->MustValidateDisplay(display_id)) {
-    return hwc3::Error::kNotValidated;
-  }
-
-  int32_t present_fence = -1;
-  auto error = Hwc2toHwc3Error(display->PresentDisplay(&present_fence));
-  if (error != hwc3::Error::kNone) {
-    return error;
-  }
-  out_display_fence.reset(present_fence);
-
-  uint32_t release_fence_count = 0;
-  error = Hwc2toHwc3Error(
-      display->GetReleaseFences(&release_fence_count, nullptr, nullptr));
-  if (error != hwc3::Error::kNone) {
-    return error;
-  }
-
-  std::vector<hwc2_layer_t> hwc_layers(release_fence_count);
-  std::vector<int32_t> hwc_fences(release_fence_count);
-  error = Hwc2toHwc3Error(display->GetReleaseFences(&release_fence_count,
-                                                    hwc_layers.data(),
-                                                    hwc_fences.data()));
-  if (error != hwc3::Error::kNone) {
-    return error;
-  }
-
-  for (size_t i = 0; i < hwc_layers.size(); i++) {
-    auto layer = Hwc2LayerToHwc3(hwc_layers[i]);
-    out_release_fences[layer] = ::android::base::unique_fd{hwc_fences[i]};
-  }
-
-  return hwc3::Error::kNone;
-}
-
 ::android::HwcDisplay* ComposerClient::GetDisplay(uint64_t display_id) {
   return hwc_->GetDisplay(display_id);
 }
@@ -642,10 +597,22 @@
   }
 
   if (command.acceptDisplayChanges) {
-    ExecuteAcceptDisplayChanges(command.display);
+    display->AcceptDisplayChanges();
   }
+
   if (command.presentDisplay) {
-    ExecutePresentDisplay(command.display);
+    if (composer_resources_->MustValidateDisplay(display_id)) {
+      cmd_result_writer_->AddError(hwc3::Error::kNotValidated);
+      return;
+    }
+    int32_t present_fence = -1;
+    std::vector<HwcDisplay::ReleaseFence> release_fences;
+    error = Hwc2toHwc3Error(
+        display->PresentStagedComposition(&present_fence, &release_fences));
+    if (error != hwc3::Error::kNone) {
+      cmd_result_writer_->AddError(error);
+      return;
+    }
   }
 }
 
@@ -1402,40 +1369,4 @@
   }
 }
 
-void ComposerClient::ExecuteAcceptDisplayChanges(int64_t display_id) {
-  auto* display = GetDisplay(display_id);
-  if (display == nullptr) {
-    cmd_result_writer_->AddError(hwc3::Error::kBadDisplay);
-    return;
-  }
-
-  auto error = Hwc2toHwc3Error(display->AcceptDisplayChanges());
-  if (error != hwc3::Error::kNone) {
-    cmd_result_writer_->AddError(error);
-    return;
-  }
-}
-
-void ComposerClient::ExecutePresentDisplay(int64_t display_id) {
-  auto* display = GetDisplay(display_id);
-  if (display == nullptr) {
-    cmd_result_writer_->AddError(hwc3::Error::kBadDisplay);
-    return;
-  }
-
-  ::android::base::unique_fd display_fence;
-  std::unordered_map<int64_t, ::android::base::unique_fd> release_fences;
-  auto error = PresentDisplayInternal(display_id, display_fence,
-                                      release_fences);
-  if (error != hwc3::Error::kNone) {
-    cmd_result_writer_->AddError(error);
-  }
-  if (cmd_result_writer_->HasError()) {
-    return;
-  }
-
-  cmd_result_writer_->AddPresentFence(display_id, std::move(display_fence));
-  cmd_result_writer_->AddReleaseFence(display_id, release_fences);
-}
-
 }  // namespace aidl::android::hardware::graphics::composer3::impl

diff --git a/hwc3/ComposerClient.h b/hwc3/ComposerClient.h
index 9b891e7..37cb8ab 100644
--- a/hwc3/ComposerClient.h
+++ b/hwc3/ComposerClient.h

@@ -171,13 +171,6 @@
   void ExecuteSetDisplayClientTarget(uint64_t display_id,
                                      const ClientTarget& command);
   void ExecuteSetDisplayOutputBuffer(uint64_t display_id, const Buffer& buffer);
-  void ExecuteAcceptDisplayChanges(int64_t display_id);
-  void ExecutePresentDisplay(int64_t display_id);
-
-  hwc3::Error PresentDisplayInternal(
-      uint64_t display_id, ::android::base::unique_fd& out_display_fence,
-      std::unordered_map<int64_t, ::android::base::unique_fd>&
-          out_release_fences);
 
   ::android::HwcDisplay* GetDisplay(uint64_t display_id);