hwc2_device/DrmHwcTwo.cpp

/*
 * Copyright (C) 2016 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-drm-two"

#include "DrmHwcTwo.h"

#include <cinttypes>

#include "backend/Backend.h"
#include "utils/log.h"

namespace android {

DrmHwcTwo::DrmHwcTwo() : resource_manager_(this){};

/* Must be called after every display attach/detach cycle */
void DrmHwcTwo::FinalizeDisplayBinding() {
  if (displays_.count(kPrimaryDisplay) == 0) {
    /* Create/update new headless display if no other displays exists
     * or reattach different display to make it primary
     */

    if (display_handles_.empty()) {
      /* Enable headless mode */
      ALOGI("No pipelines available. Creating null-display for headless mode");
      displays_[kPrimaryDisplay] = std::make_unique<
          HwcDisplay>(nullptr, kPrimaryDisplay, HWC2::DisplayType::Physical,
                      this);
    } else {
      auto *pipe = display_handles_.begin()->first;
      ALOGI("Primary display was disconnected, reattaching '%s' as new primary",
            pipe->connector->Get()->GetName().c_str());
      UnbindDisplay(pipe);
      BindDisplay(pipe);
      if (displays_.count(kPrimaryDisplay) == 0) {
        ALOGE("FIXME!!! Still no primary display after reattaching...");
      }
    }
  }

  // Finally, send hotplug events to the client
  for (auto &dhe : deferred_hotplug_events_) {
    SendHotplugEventToClient(dhe.first, dhe.second);
  }
  deferred_hotplug_events_.clear();
}

bool DrmHwcTwo::BindDisplay(DrmDisplayPipeline *pipeline) {
  if (display_handles_.count(pipeline) != 0) {
    ALOGE("%s, pipeline is already used by another display, FIXME!!!: %p",
          __func__, pipeline);
    return false;
  }

  uint32_t disp_handle = kPrimaryDisplay;

  if (displays_.count(kPrimaryDisplay) != 0 &&
      !displays_[kPrimaryDisplay]->IsInHeadlessMode()) {
    disp_handle = ++last_display_handle_;
  }

  auto disp = std::make_unique<HwcDisplay>(pipeline, disp_handle,
                                           HWC2::DisplayType::Physical, this);

  if (disp_handle == kPrimaryDisplay) {
    displays_.erase(disp_handle);
  }

  ALOGI("Attaching pipeline '%s' to the display #%d%s",
        pipeline->connector->Get()->GetName().c_str(), (int)disp_handle,
        disp_handle == kPrimaryDisplay ? " (Primary)" : "");

  displays_[disp_handle] = std::move(disp);
  display_handles_[pipeline] = disp_handle;

  return true;
}

bool DrmHwcTwo::UnbindDisplay(DrmDisplayPipeline *pipeline) {
  if (display_handles_.count(pipeline) == 0) {
    ALOGE("%s, can't find the display, pipeline: %p", __func__, pipeline);
    return false;
  }
  auto handle = display_handles_[pipeline];

  ALOGI("Detaching the pipeline '%s' from the display #%i%s",
        pipeline->connector->Get()->GetName().c_str(), (int)handle,
        handle == kPrimaryDisplay ? " (Primary)" : "");

  display_handles_.erase(pipeline);
  if (displays_.count(handle) == 0) {
    ALOGE("%s, can't find the display, handle: %" PRIu64, __func__, handle);
    return false;
  }
  displays_.erase(handle);
  return true;
}

HWC2::Error DrmHwcTwo::CreateVirtualDisplay(uint32_t /*width*/,
                                            uint32_t /*height*/,
                                            int32_t * /*format*/,
                                            hwc2_display_t * /*display*/) {
  // TODO(nobody): Implement virtual display
  return HWC2::Error::Unsupported;
}

HWC2::Error DrmHwcTwo::DestroyVirtualDisplay(hwc2_display_t /*display*/) {
  // TODO(nobody): Implement virtual display
  return HWC2::Error::Unsupported;
}

void DrmHwcTwo::Dump(uint32_t *outSize, char *outBuffer) {
  if (outBuffer != nullptr) {
    auto copied_bytes = mDumpString.copy(outBuffer, *outSize);
    *outSize = static_cast<uint32_t>(copied_bytes);
    return;
  }

  std::stringstream output;

  output << "-- drm_hwcomposer --\n\n";

  for (auto &disp : displays_)
    output << disp.second->Dump();

  mDumpString = output.str();
  *outSize = static_cast<uint32_t>(mDumpString.size());
}

uint32_t DrmHwcTwo::GetMaxVirtualDisplayCount() {
  // TODO(nobody): Implement virtual display
  return 0;
}

HWC2::Error DrmHwcTwo::RegisterCallback(int32_t descriptor,
                                        hwc2_callback_data_t data,
                                        hwc2_function_pointer_t function) {
  switch (static_cast<HWC2::Callback>(descriptor)) {
    case HWC2::Callback::Hotplug: {
      hotplug_callback_ = std::make_pair(HWC2_PFN_HOTPLUG(function), data);
      if (function != nullptr) {
        resource_manager_.Init();
      } else {
        resource_manager_.DeInit();
        /* Headless display may still be here, remove it */
        displays_.erase(kPrimaryDisplay);
      }
      break;
    }
    case HWC2::Callback::Refresh: {
      refresh_callback_ = std::make_pair(HWC2_PFN_REFRESH(function), data);
      break;
    }
    case HWC2::Callback::Vsync: {
      vsync_callback_ = std::make_pair(HWC2_PFN_VSYNC(function), data);
      break;
    }
#if PLATFORM_SDK_VERSION > 29
    case HWC2::Callback::Vsync_2_4: {
      vsync_2_4_callback_ = std::make_pair(HWC2_PFN_VSYNC_2_4(function), data);
      break;
    }
#endif
    default:
      break;
  }
  return HWC2::Error::None;
}

void DrmHwcTwo::SendHotplugEventToClient(hwc2_display_t displayid,
                                         bool connected) {
  auto &mutex = GetResMan().GetMainLock();
  if (mutex.try_lock()) {
    ALOGE("FIXME!!!: Main mutex must be locked in %s", __func__);
    mutex.unlock();
    return;
  }

  auto hc = hotplug_callback_;
  if (hc.first != nullptr && hc.second != nullptr) {
    /* For some reason CLIENT will call HWC2 API in hotplug callback handler,
     * which will cause deadlock . Unlock main mutex to prevent this.
     */
    mutex.unlock();
    hc.first(hc.second, displayid,
             connected == DRM_MODE_CONNECTED ? HWC2_CONNECTION_CONNECTED
                                             : HWC2_CONNECTION_DISCONNECTED);
    mutex.lock();
  }
}

}  // namespace android