hwc2_device/HwcDisplay.cpp

/*
 * Copyright (C) 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define LOG_TAG "hwc-display"
#define ATRACE_TAG ATRACE_TAG_GRAPHICS

#include "HwcDisplay.h"

#include "DrmHwcTwo.h"
#include "backend/BackendManager.h"
#include "bufferinfo/BufferInfoGetter.h"
#include "utils/log.h"
#include "utils/properties.h"

namespace android {

std::string HwcDisplay::DumpDelta(HwcDisplay::Stats delta) {
  if (delta.total_pixops_ == 0)
    return "No stats yet";
  double ratio = 1.0 - double(delta.gpu_pixops_) / double(delta.total_pixops_);

  std::stringstream ss;
  ss << " Total frames count: " << delta.total_frames_ << "\n"
     << " Failed to test commit frames: " << delta.failed_kms_validate_ << "\n"
     << " Failed to commit frames: " << delta.failed_kms_present_ << "\n"
     << ((delta.failed_kms_present_ > 0)
             ? " !!! Internal failure, FIX it please\n"
             : "")
     << " Flattened frames: " << delta.frames_flattened_ << "\n"
     << " Pixel operations (free units)"
     << " : [TOTAL: " << delta.total_pixops_ << " / GPU: " << delta.gpu_pixops_
     << "]\n"
     << " Composition efficiency: " << ratio;

  return ss.str();
}

std::string HwcDisplay::Dump() {
  std::string flattening_state_str;
  switch (flattenning_state_) {
    case ClientFlattenningState::Disabled:
      flattening_state_str = "Disabled";
      break;
    case ClientFlattenningState::NotRequired:
      flattening_state_str = "Not needed";
      break;
    case ClientFlattenningState::Flattened:
      flattening_state_str = "Active";
      break;
    case ClientFlattenningState::ClientRefreshRequested:
      flattening_state_str = "Refresh requested";
      break;
    default:
      flattening_state_str = std::to_string(flattenning_state_) +
                             " VSync remains";
  }

  std::stringstream ss;
  ss << "- Display on: " << connector_->name() << "\n"
     << "  Flattening state: " << flattening_state_str << "\n"
     << "Statistics since system boot:\n"
     << DumpDelta(total_stats_) << "\n\n"
     << "Statistics since last dumpsys request:\n"
     << DumpDelta(total_stats_.minus(prev_stats_)) << "\n\n";

  memcpy(&prev_stats_, &total_stats_, sizeof(Stats));
  return ss.str();
}

HwcDisplay::HwcDisplay(ResourceManager *resource_manager, DrmDevice *drm,
                       hwc2_display_t handle, HWC2::DisplayType type,
                       DrmHwcTwo *hwc2)
    : hwc2_(hwc2),
      resource_manager_(resource_manager),
      drm_(drm),
      handle_(handle),
      type_(type),
      color_transform_hint_(HAL_COLOR_TRANSFORM_IDENTITY) {
  // clang-format off
  color_transform_matrix_ = {1.0, 0.0, 0.0, 0.0,
                             0.0, 1.0, 0.0, 0.0,
                             0.0, 0.0, 1.0, 0.0,
                             0.0, 0.0, 0.0, 1.0};
  // clang-format on
}

void HwcDisplay::ClearDisplay() {
  if (IsInHeadlessMode()) {
    ALOGE("%s: Headless mode, should never reach here: ", __func__);
    return;
  }

  AtomicCommitArgs a_args = {.clear_active_composition = true};
  compositor_.ExecuteAtomicCommit(a_args);
}

HWC2::Error HwcDisplay::Init(std::vector<DrmPlane *> *planes) {
  int display = static_cast<int>(handle_);
  int ret = compositor_.Init(resource_manager_, display);
  if (ret) {
    ALOGE("Failed display compositor init for display %d (%d)", display, ret);
    return HWC2::Error::NoResources;
  }

  // Split up the given display planes into primary and overlay to properly
  // interface with the composition
  char use_overlay_planes_prop[PROPERTY_VALUE_MAX];
  property_get("vendor.hwc.drm.use_overlay_planes", use_overlay_planes_prop,
               "1");
  bool use_overlay_planes = strtol(use_overlay_planes_prop, nullptr, 10);
  for (auto &plane : *planes) {
    if (plane->GetType() == DRM_PLANE_TYPE_PRIMARY)
      primary_planes_.push_back(plane);
    else if (use_overlay_planes && (plane)->GetType() == DRM_PLANE_TYPE_OVERLAY)
      overlay_planes_.push_back(plane);
  }

  crtc_ = drm_->GetCrtcForDisplay(display);
  if (!crtc_) {
    ALOGE("Failed to get crtc for display %d", display);
    return HWC2::Error::BadDisplay;
  }

  connector_ = drm_->GetConnectorForDisplay(display);
  if (!connector_) {
    ALOGE("Failed to get connector for display %d", display);
    return HWC2::Error::BadDisplay;
  }

  ret = vsync_worker_.Init(drm_, display, [this](int64_t timestamp) {
    const std::lock_guard<std::mutex> lock(hwc2_->GetResMan().GetMainLock());
    /* vsync callback */
#if PLATFORM_SDK_VERSION > 29
    if (hwc2_->vsync_2_4_callback_.first != nullptr &&
        hwc2_->vsync_2_4_callback_.second != nullptr) {
      hwc2_vsync_period_t period_ns{};
      GetDisplayVsyncPeriod(&period_ns);
      hwc2_->vsync_2_4_callback_.first(hwc2_->vsync_2_4_callback_.second,
                                       handle_, timestamp, period_ns);
    } else
#endif
        if (hwc2_->vsync_callback_.first != nullptr &&
            hwc2_->vsync_callback_.second != nullptr) {
      hwc2_->vsync_callback_.first(hwc2_->vsync_callback_.second, handle_,
                                   timestamp);
    }
  });
  if (ret) {
    ALOGE("Failed to create event worker for d=%d %d\n", display, ret);
    return HWC2::Error::BadDisplay;
  }

  ret = flattening_vsync_worker_
            .Init(drm_, display, [this](int64_t /*timestamp*/) {
              const std::lock_guard<std::mutex> lock(
                  hwc2_->GetResMan().GetMainLock());
              /* Frontend flattening */
              if (flattenning_state_ >
                      ClientFlattenningState::ClientRefreshRequested &&
                  --flattenning_state_ ==
                      ClientFlattenningState::ClientRefreshRequested &&
                  hwc2_->refresh_callback_.first != nullptr &&
                  hwc2_->refresh_callback_.second != nullptr) {
                hwc2_->refresh_callback_.first(hwc2_->refresh_callback_.second,
                                               handle_);
                flattening_vsync_worker_.VSyncControl(false);
              }
            });
  if (ret) {
    ALOGE("Failed to create event worker for d=%d %d\n", display, ret);
    return HWC2::Error::BadDisplay;
  }

  ret = BackendManager::GetInstance().SetBackendForDisplay(this);
  if (ret) {
    ALOGE("Failed to set backend for d=%d %d\n", display, ret);
    return HWC2::Error::BadDisplay;
  }

  client_layer_.SetLayerBlendMode(HWC2_BLEND_MODE_PREMULTIPLIED);

  return ChosePreferredConfig();
}

HWC2::Error HwcDisplay::ChosePreferredConfig() {
  HWC2::Error err = configs_.Update(*connector_);
  if (!IsInHeadlessMode() && err != HWC2::Error::None)
    return HWC2::Error::BadDisplay;

  return SetActiveConfig(configs_.preferred_config_id);
}

HWC2::Error HwcDisplay::AcceptDisplayChanges() {
  for (std::pair<const hwc2_layer_t, HwcLayer> &l : layers_)
    l.second.AcceptTypeChange();
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::CreateLayer(hwc2_layer_t *layer) {
  layers_.emplace(static_cast<hwc2_layer_t>(layer_idx_), HwcLayer());
  *layer = static_cast<hwc2_layer_t>(layer_idx_);
  ++layer_idx_;
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::DestroyLayer(hwc2_layer_t layer) {
  if (!get_layer(layer))
    return HWC2::Error::BadLayer;

  layers_.erase(layer);
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetActiveConfig(hwc2_config_t *config) const {
  if (configs_.hwc_configs.count(configs_.active_config_id) == 0)
    return HWC2::Error::BadConfig;

  *config = configs_.active_config_id;
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetChangedCompositionTypes(uint32_t *num_elements,
                                                   hwc2_layer_t *layers,
                                                   int32_t *types) {
  if (IsInHeadlessMode()) {
    *num_elements = 0;
    return HWC2::Error::None;
  }

  uint32_t num_changes = 0;
  for (std::pair<const hwc2_layer_t, HwcLayer> &l : layers_) {
    if (l.second.IsTypeChanged()) {
      if (layers && num_changes < *num_elements)
        layers[num_changes] = l.first;
      if (types && num_changes < *num_elements)
        types[num_changes] = static_cast<int32_t>(l.second.GetValidatedType());
      ++num_changes;
    }
  }
  if (!layers && !types)
    *num_elements = num_changes;
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetClientTargetSupport(uint32_t width, uint32_t height,
                                               int32_t /*format*/,
                                               int32_t dataspace) {
  std::pair<uint32_t, uint32_t> min = drm_->min_resolution();
  std::pair<uint32_t, uint32_t> max = drm_->max_resolution();
  if (IsInHeadlessMode()) {
    return HWC2::Error::None;
  }

  if (width < min.first || height < min.second)
    return HWC2::Error::Unsupported;

  if (width > max.first || height > max.second)
    return HWC2::Error::Unsupported;

  if (dataspace != HAL_DATASPACE_UNKNOWN)
    return HWC2::Error::Unsupported;

  // TODO(nobody): Validate format can be handled by either GL or planes
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetColorModes(uint32_t *num_modes, int32_t *modes) {
  if (!modes)
    *num_modes = 1;

  if (modes)
    *modes = HAL_COLOR_MODE_NATIVE;

  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetDisplayAttribute(hwc2_config_t config,
                                            int32_t attribute_in,
                                            int32_t *value) {
  int conf = static_cast<int>(config);

  if (configs_.hwc_configs.count(conf) == 0) {
    ALOGE("Could not find active mode for %d", conf);
    return HWC2::Error::BadConfig;
  }

  auto &hwc_config = configs_.hwc_configs[conf];

  static const int32_t kUmPerInch = 25400;
  uint32_t mm_width = configs_.mm_width;
  uint32_t mm_height = configs_.mm_height;
  auto attribute = static_cast<HWC2::Attribute>(attribute_in);
  switch (attribute) {
    case HWC2::Attribute::Width:
      *value = static_cast<int>(hwc_config.mode.h_display());
      break;
    case HWC2::Attribute::Height:
      *value = static_cast<int>(hwc_config.mode.v_display());
      break;
    case HWC2::Attribute::VsyncPeriod:
      // in nanoseconds
      *value = static_cast<int>(1E9 / hwc_config.mode.v_refresh());
      break;
    case HWC2::Attribute::DpiX:
      // Dots per 1000 inches
      *value = mm_width ? static_cast<int>(hwc_config.mode.h_display() *
                                           kUmPerInch / mm_width)
                        : -1;
      break;
    case HWC2::Attribute::DpiY:
      // Dots per 1000 inches
      *value = mm_height ? static_cast<int>(hwc_config.mode.v_display() *
                                            kUmPerInch / mm_height)
                         : -1;
      break;
#if PLATFORM_SDK_VERSION > 29
    case HWC2::Attribute::ConfigGroup:
      /* Dispite ConfigGroup is a part of HWC2.4 API, framework
       * able to request it even if service @2.1 is used */
      *value = hwc_config.group_id;
      break;
#endif
    default:
      *value = -1;
      return HWC2::Error::BadConfig;
  }
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetDisplayConfigs(uint32_t *num_configs,
                                          hwc2_config_t *configs) {
  uint32_t idx = 0;
  for (auto &hwc_config : configs_.hwc_configs) {
    if (hwc_config.second.disabled) {
      continue;
    }

    if (configs != nullptr) {
      if (idx >= *num_configs) {
        break;
      }
      configs[idx] = hwc_config.second.id;
    }

    idx++;
  }
  *num_configs = idx;
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetDisplayName(uint32_t *size, char *name) {
  std::ostringstream stream;
  stream << "display-" << connector_->id();
  std::string string = stream.str();
  size_t length = string.length();
  if (!name) {
    *size = length;
    return HWC2::Error::None;
  }

  *size = std::min<uint32_t>(static_cast<uint32_t>(length - 1), *size);
  strncpy(name, string.c_str(), *size);
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetDisplayRequests(int32_t * /*display_requests*/,
                                           uint32_t *num_elements,
                                           hwc2_layer_t * /*layers*/,
                                           int32_t * /*layer_requests*/) {
  // TODO(nobody): I think virtual display should request
  //      HWC2_DISPLAY_REQUEST_WRITE_CLIENT_TARGET_TO_OUTPUT here
  *num_elements = 0;
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetDisplayType(int32_t *type) {
  *type = static_cast<int32_t>(type_);
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetDozeSupport(int32_t *support) {
  *support = 0;
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetHdrCapabilities(uint32_t *num_types,
                                           int32_t * /*types*/,
                                           float * /*max_luminance*/,
                                           float * /*max_average_luminance*/,
                                           float * /*min_luminance*/) {
  *num_types = 0;
  return HWC2::Error::None;
}

/* Find API details at:
 * https://cs.android.com/android/platform/superproject/+/android-11.0.0_r3:hardware/libhardware/include/hardware/hwcomposer2.h;l=1767
 */
HWC2::Error HwcDisplay::GetReleaseFences(uint32_t *num_elements,
                                         hwc2_layer_t *layers,
                                         int32_t *fences) {
  if (IsInHeadlessMode()) {
    *num_elements = 0;
    return HWC2::Error::None;
  }

  uint32_t num_layers = 0;

  for (std::pair<const hwc2_layer_t, HwcLayer> &l : layers_) {
    ++num_layers;
    if (layers == nullptr || fences == nullptr)
      continue;

    if (num_layers > *num_elements) {
      ALOGW("Overflow num_elements %d/%d", num_layers, *num_elements);
      return HWC2::Error::None;
    }

    layers[num_layers - 1] = l.first;
    fences[num_layers - 1] = l.second.GetReleaseFence().Release();
  }
  *num_elements = num_layers;
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::CreateComposition(AtomicCommitArgs &a_args) {
  if (IsInHeadlessMode()) {
    ALOGE("%s: Display is in headless mode, should never reach here", __func__);
    return HWC2::Error::None;
  }

  // order the layers by z-order
  bool use_client_layer = false;
  uint32_t client_z_order = UINT32_MAX;
  std::map<uint32_t, HwcLayer *> z_map;
  for (std::pair<const hwc2_layer_t, HwcLayer> &l : layers_) {
    switch (l.second.GetValidatedType()) {
      case HWC2::Composition::Device:
        z_map.emplace(std::make_pair(l.second.GetZOrder(), &l.second));
        break;
      case HWC2::Composition::Client:
        // Place it at the z_order of the lowest client layer
        use_client_layer = true;
        client_z_order = std::min(client_z_order, l.second.GetZOrder());
        break;
      default:
        continue;
    }
  }
  if (use_client_layer)
    z_map.emplace(std::make_pair(client_z_order, &client_layer_));

  if (z_map.empty())
    return HWC2::Error::BadLayer;

  std::vector<DrmHwcLayer> composition_layers;

  // now that they're ordered by z, add them to the composition
  for (std::pair<const uint32_t, HwcLayer *> &l : z_map) {
    DrmHwcLayer layer;
    l.second->PopulateDrmLayer(&layer);
    int ret = layer.ImportBuffer(drm_);
    if (ret) {
      ALOGE("Failed to import layer, ret=%d", ret);
      return HWC2::Error::NoResources;
    }
    composition_layers.emplace_back(std::move(layer));
  }

  auto composition = std::make_shared<DrmDisplayComposition>(crtc_);

  // TODO(nobody): Don't always assume geometry changed
  int ret = composition->SetLayers(composition_layers.data(),
                                   composition_layers.size());
  if (ret) {
    ALOGE("Failed to set layers in the composition ret=%d", ret);
    return HWC2::Error::BadLayer;
  }

  std::vector<DrmPlane *> primary_planes(primary_planes_);
  std::vector<DrmPlane *> overlay_planes(overlay_planes_);
  ret = composition->Plan(&primary_planes, &overlay_planes);
  if (ret) {
    ALOGV("Failed to plan the composition ret=%d", ret);
    return HWC2::Error::BadConfig;
  }

  a_args.composition = composition;
  if (staged_mode) {
    a_args.display_mode = *staged_mode;
  }
  ret = compositor_.ExecuteAtomicCommit(a_args);

  if (ret) {
    if (!a_args.test_only)
      ALOGE("Failed to apply the frame composition ret=%d", ret);
    return HWC2::Error::BadParameter;
  }

  if (!a_args.test_only) {
    staged_mode.reset();
  }

  return HWC2::Error::None;
}

/* Find API details at:
 * https://cs.android.com/android/platform/superproject/+/android-11.0.0_r3:hardware/libhardware/include/hardware/hwcomposer2.h;l=1805
 */
HWC2::Error HwcDisplay::PresentDisplay(int32_t *present_fence) {
  if (IsInHeadlessMode()) {
    *present_fence = -1;
    return HWC2::Error::None;
  }
  HWC2::Error ret{};

  ++total_stats_.total_frames_;

  AtomicCommitArgs a_args{};
  ret = CreateComposition(a_args);

  if (ret != HWC2::Error::None)
    ++total_stats_.failed_kms_present_;

  if (ret == HWC2::Error::BadLayer) {
    // Can we really have no client or device layers?
    *present_fence = -1;
    return HWC2::Error::None;
  }
  if (ret != HWC2::Error::None)
    return ret;

  *present_fence = a_args.out_fence.Release();

  ++frame_no_;
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::SetActiveConfig(hwc2_config_t config) {
  int conf = static_cast<int>(config);

  if (configs_.hwc_configs.count(conf) == 0) {
    ALOGE("Could not find active mode for %d", conf);
    return HWC2::Error::BadConfig;
  }

  auto &mode = configs_.hwc_configs[conf].mode;

  staged_mode = mode;

  configs_.active_config_id = conf;

  // Setup the client layer's dimensions
  hwc_rect_t display_frame = {.left = 0,
                              .top = 0,
                              .right = static_cast<int>(mode.h_display()),
                              .bottom = static_cast<int>(mode.v_display())};
  client_layer_.SetLayerDisplayFrame(display_frame);

  return HWC2::Error::None;
}

/* Find API details at:
 * https://cs.android.com/android/platform/superproject/+/android-11.0.0_r3:hardware/libhardware/include/hardware/hwcomposer2.h;l=1861
 */
HWC2::Error HwcDisplay::SetClientTarget(buffer_handle_t target,
                                        int32_t acquire_fence,
                                        int32_t dataspace,
                                        hwc_region_t /*damage*/) {
  client_layer_.SetLayerBuffer(target, acquire_fence);
  client_layer_.SetLayerDataspace(dataspace);

  /*
   * target can be nullptr, this does mean the Composer Service is calling
   * cleanDisplayResources() on after receiving HOTPLUG event. See more at:
   * https://cs.android.com/android/platform/superproject/+/master:hardware/interfaces/graphics/composer/2.1/utils/hal/include/composer-hal/2.1/ComposerClient.h;l=350;drc=944b68180b008456ed2eb4d4d329e33b19bd5166
   */
  if (target == nullptr) {
    return HWC2::Error::None;
  }

  /* TODO: Do not update source_crop every call.
   * It makes sense to do it once after every hotplug event. */
  HwcDrmBo bo{};
  BufferInfoGetter::GetInstance()->ConvertBoInfo(target, &bo);

  hwc_frect_t source_crop = {.left = 0.0F,
                             .top = 0.0F,
                             .right = static_cast<float>(bo.width),
                             .bottom = static_cast<float>(bo.height)};
  client_layer_.SetLayerSourceCrop(source_crop);

  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::SetColorMode(int32_t mode) {
  if (mode < HAL_COLOR_MODE_NATIVE || mode > HAL_COLOR_MODE_BT2100_HLG)
    return HWC2::Error::BadParameter;

  if (mode != HAL_COLOR_MODE_NATIVE)
    return HWC2::Error::Unsupported;

  color_mode_ = mode;
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::SetColorTransform(const float *matrix, int32_t hint) {
  if (hint < HAL_COLOR_TRANSFORM_IDENTITY ||
      hint > HAL_COLOR_TRANSFORM_CORRECT_TRITANOPIA)
    return HWC2::Error::BadParameter;

  if (!matrix && hint == HAL_COLOR_TRANSFORM_ARBITRARY_MATRIX)
    return HWC2::Error::BadParameter;

  color_transform_hint_ = static_cast<android_color_transform_t>(hint);
  if (color_transform_hint_ == HAL_COLOR_TRANSFORM_ARBITRARY_MATRIX)
    std::copy(matrix, matrix + MATRIX_SIZE, color_transform_matrix_.begin());

  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::SetOutputBuffer(buffer_handle_t /*buffer*/,
                                        int32_t /*release_fence*/) {
  // TODO(nobody): Need virtual display support
  return HWC2::Error::Unsupported;
}

HWC2::Error HwcDisplay::SetPowerMode(int32_t mode_in) {
  if (IsInHeadlessMode()) {
    return HWC2::Error::None;
  }

  auto mode = static_cast<HWC2::PowerMode>(mode_in);
  AtomicCommitArgs a_args{};

  switch (mode) {
    case HWC2::PowerMode::Off:
      a_args.active = false;
      break;
    case HWC2::PowerMode::On:
      /*
       * Setting the display to active before we have a composition
       * can break some drivers, so skip setting a_args.active to
       * true, as the next composition frame will implicitly activate
       * the display
       */
      return compositor_.ActivateDisplayUsingDPMS() == 0
                 ? HWC2::Error::None
                 : HWC2::Error::BadParameter;
      break;
    case HWC2::PowerMode::Doze:
    case HWC2::PowerMode::DozeSuspend:
      return HWC2::Error::Unsupported;
    default:
      ALOGI("Power mode %d is unsupported\n", mode);
      return HWC2::Error::BadParameter;
  };

  int err = compositor_.ExecuteAtomicCommit(a_args);
  if (err) {
    ALOGE("Failed to apply the dpms composition err=%d", err);
    return HWC2::Error::BadParameter;
  }
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::SetVsyncEnabled(int32_t enabled) {
  vsync_worker_.VSyncControl(HWC2_VSYNC_ENABLE == enabled);
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::ValidateDisplay(uint32_t *num_types,
                                        uint32_t *num_requests) {
  if (IsInHeadlessMode()) {
    *num_types = *num_requests = 0;
    return HWC2::Error::None;
  }
  return backend_->ValidateDisplay(this, num_types, num_requests);
}

std::vector<HwcLayer *> HwcDisplay::GetOrderLayersByZPos() {
  std::vector<HwcLayer *> ordered_layers;
  ordered_layers.reserve(layers_.size());

  for (auto &[handle, layer] : layers_) {
    ordered_layers.emplace_back(&layer);
  }

  std::sort(std::begin(ordered_layers), std::end(ordered_layers),
            [](const HwcLayer *lhs, const HwcLayer *rhs) {
              return lhs->GetZOrder() < rhs->GetZOrder();
            });

  return ordered_layers;
}

#if PLATFORM_SDK_VERSION > 29
HWC2::Error HwcDisplay::GetDisplayConnectionType(uint32_t *outType) {
  if (connector_->internal())
    *outType = static_cast<uint32_t>(HWC2::DisplayConnectionType::Internal);
  else if (connector_->external())
    *outType = static_cast<uint32_t>(HWC2::DisplayConnectionType::External);
  else
    return HWC2::Error::BadConfig;

  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetDisplayVsyncPeriod(
    hwc2_vsync_period_t *outVsyncPeriod /* ns */) {
  return GetDisplayAttribute(configs_.active_config_id,
                             HWC2_ATTRIBUTE_VSYNC_PERIOD,
                             (int32_t *)(outVsyncPeriod));
}

HWC2::Error HwcDisplay::SetActiveConfigWithConstraints(
    hwc2_config_t /*config*/,
    hwc_vsync_period_change_constraints_t *vsyncPeriodChangeConstraints,
    hwc_vsync_period_change_timeline_t *outTimeline) {
  if (vsyncPeriodChangeConstraints == nullptr || outTimeline == nullptr) {
    return HWC2::Error::BadParameter;
  }

  return HWC2::Error::BadConfig;
}

HWC2::Error HwcDisplay::SetAutoLowLatencyMode(bool /*on*/) {
  return HWC2::Error::Unsupported;
}

HWC2::Error HwcDisplay::GetSupportedContentTypes(
    uint32_t *outNumSupportedContentTypes,
    const uint32_t *outSupportedContentTypes) {
  if (outSupportedContentTypes == nullptr)
    *outNumSupportedContentTypes = 0;

  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::SetContentType(int32_t contentType) {
  if (contentType != HWC2_CONTENT_TYPE_NONE)
    return HWC2::Error::Unsupported;

  /* TODO: Map to the DRM Connector property:
   * https://elixir.bootlin.com/linux/v5.4-rc5/source/drivers/gpu/drm/drm_connector.c#L809
   */

  return HWC2::Error::None;
}
#endif

#if PLATFORM_SDK_VERSION > 28
HWC2::Error HwcDisplay::GetDisplayIdentificationData(uint8_t *outPort,
                                                     uint32_t *outDataSize,
                                                     uint8_t *outData) {
  auto blob = connector_->GetEdidBlob();

  if (!blob) {
    ALOGE("Failed to get edid property value.");
    return HWC2::Error::Unsupported;
  }

  if (outData) {
    *outDataSize = std::min(*outDataSize, blob->length);
    memcpy(outData, blob->data, *outDataSize);
  } else {
    *outDataSize = blob->length;
  }
  *outPort = connector_->id();

  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetDisplayCapabilities(uint32_t *outNumCapabilities,
                                               uint32_t * /*outCapabilities*/) {
  if (outNumCapabilities == nullptr) {
    return HWC2::Error::BadParameter;
  }

  *outNumCapabilities = 0;

  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::GetDisplayBrightnessSupport(bool *supported) {
  *supported = false;
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::SetDisplayBrightness(float /* brightness */) {
  return HWC2::Error::Unsupported;
}

#endif /* PLATFORM_SDK_VERSION > 28 */

#if PLATFORM_SDK_VERSION > 27

HWC2::Error HwcDisplay::GetRenderIntents(
    int32_t mode, uint32_t *outNumIntents,
    int32_t * /*android_render_intent_v1_1_t*/ outIntents) {
  if (mode != HAL_COLOR_MODE_NATIVE) {
    return HWC2::Error::BadParameter;
  }

  if (outIntents == nullptr) {
    *outNumIntents = 1;
    return HWC2::Error::None;
  }
  *outNumIntents = 1;
  outIntents[0] = HAL_RENDER_INTENT_COLORIMETRIC;
  return HWC2::Error::None;
}

HWC2::Error HwcDisplay::SetColorModeWithIntent(int32_t mode, int32_t intent) {
  if (intent < HAL_RENDER_INTENT_COLORIMETRIC ||
      intent > HAL_RENDER_INTENT_TONE_MAP_ENHANCE)
    return HWC2::Error::BadParameter;

  if (mode < HAL_COLOR_MODE_NATIVE || mode > HAL_COLOR_MODE_BT2100_HLG)
    return HWC2::Error::BadParameter;

  if (mode != HAL_COLOR_MODE_NATIVE)
    return HWC2::Error::Unsupported;

  if (intent != HAL_RENDER_INTENT_COLORIMETRIC)
    return HWC2::Error::Unsupported;

  color_mode_ = mode;
  return HWC2::Error::None;
}

#endif /* PLATFORM_SDK_VERSION > 27 */

const Backend *HwcDisplay::backend() const {
  return backend_.get();
}

void HwcDisplay::set_backend(std::unique_ptr<Backend> backend) {
  backend_ = std::move(backend);
}

}  // namespace android