EDID support for external display hotplug

The hardware_composer caches the edid when a new hotplug event fires
(connected and disconnected). The display services uses this cached edid
when the edid is requested.

Bug: 141007548
Test: Manual, ran on mtp device with wave optics plugged in and
unplugged and verified edid with: "adb shell dumpsys SurfaceFlinger --display-id"

Change-Id: I4556e1d8a3f8677b1d9301d9afbc40d514c86e27
diff --git a/libs/vr/libvrflinger/display_service.cpp b/libs/vr/libvrflinger/display_service.cpp
index 5a9360c..582fed3 100644
--- a/libs/vr/libvrflinger/display_service.cpp
+++ b/libs/vr/libvrflinger/display_service.cpp
@@ -18,6 +18,8 @@
 #include <private/dvr/trusted_uids.h>
 #include <private/dvr/types.h>
 
+#include "DisplayHardware/DisplayIdentification.h"
+
 using android::dvr::display::DisplayProtocol;
 using android::pdx::Channel;
 using android::pdx::ErrorStatus;
@@ -44,19 +46,6 @@
            Endpoint::Create(display::DisplayProtocol::kClientPath)) {
     hardware_composer_.Initialize(
         hidl, primary_display_id, request_display_callback);
-
-    uint8_t port;
-    const auto error = hidl->getDisplayIdentificationData(
-        primary_display_id, &display_identification_port_,
-        &display_identification_data_);
-    if (error != android::hardware::graphics::composer::V2_1::Error::NONE) {
-      if (error !=
-          android::hardware::graphics::composer::V2_1::Error::UNSUPPORTED) {
-        ALOGI("DisplayService: identification data error\n");
-      } else {
-        ALOGI("DisplayService: identification data unsupported\n");
-      }
-    }
 }
 
 bool DisplayService::IsInitialized() const {
@@ -212,6 +201,7 @@
 pdx::Status<std::string> DisplayService::OnGetConfigurationData(
     pdx::Message& /*message*/, display::ConfigFileType config_type) {
   std::string property_name;
+  DisplayIdentificationData display_identification_data;
   switch (config_type) {
     case display::ConfigFileType::kLensMetrics:
       property_name = kDvrLensMetricsProperty;
@@ -223,11 +213,13 @@
       property_name = kDvrDeviceConfigProperty;
       break;
     case display::ConfigFileType::kDeviceEdid:
-      if (display_identification_data_.size() == 0) {
+      display_identification_data =
+          hardware_composer_.GetCurrentDisplayIdentificationData();
+      if (display_identification_data.size() == 0) {
         return ErrorStatus(ENOENT);
       }
-      return std::string(display_identification_data_.begin(),
-                         display_identification_data_.end());
+      return std::string(display_identification_data.begin(),
+                         display_identification_data.end());
     default:
       return ErrorStatus(EINVAL);
   }
@@ -246,7 +238,7 @@
 
 pdx::Status<uint8_t> DisplayService::OnGetDisplayIdentificationPort(
     pdx::Message& /*message*/) {
-  return display_identification_port_;
+  return hardware_composer_.GetCurrentDisplayPort();
 }
 
 // Creates a new DisplaySurface and associates it with this channel. This may
diff --git a/libs/vr/libvrflinger/display_service.h b/libs/vr/libvrflinger/display_service.h
index 06ba566..89f1eae 100644
--- a/libs/vr/libvrflinger/display_service.h
+++ b/libs/vr/libvrflinger/display_service.h
@@ -18,8 +18,6 @@
 #include "epoll_event_dispatcher.h"
 #include "hardware_composer.h"
 
-#include "DisplayHardware/DisplayIdentification.h"
-
 namespace android {
 namespace dvr {
 
@@ -120,9 +118,6 @@
 
   DisplayService(const DisplayService&) = delete;
   void operator=(const DisplayService&) = delete;
-
-  DisplayIdentificationData display_identification_data_;
-  uint8_t display_identification_port_;
 };
 
 }  // namespace dvr
diff --git a/libs/vr/libvrflinger/hardware_composer.cpp b/libs/vr/libvrflinger/hardware_composer.cpp
index 9072d89..67607af 100644
--- a/libs/vr/libvrflinger/hardware_composer.cpp
+++ b/libs/vr/libvrflinger/hardware_composer.cpp
@@ -137,6 +137,20 @@
   composer_callback_->SetVsyncService(nullptr);
 }
 
+void HardwareComposer::UpdateEdidData(Hwc2::Composer* composer,
+                                      hwc2_display_t hw_id) {
+  const auto error = composer->getDisplayIdentificationData(
+      hw_id, &display_port_, &display_identification_data_);
+  if (error != android::hardware::graphics::composer::V2_1::Error::NONE) {
+    if (error !=
+        android::hardware::graphics::composer::V2_1::Error::UNSUPPORTED) {
+      ALOGI("hardware_composer: identification data error\n");
+    } else {
+      ALOGI("hardware_composer: identification data unsupported\n");
+    }
+  }
+}
+
 bool HardwareComposer::Initialize(
     Hwc2::Composer* composer, hwc2_display_t primary_display_id,
     RequestDisplayCallback request_display_callback) {
@@ -164,6 +178,8 @@
       "HardwareComposer: Failed to create interrupt event fd : %s",
       strerror(errno));
 
+  UpdateEdidData(composer, primary_display_id);
+
   post_thread_ = std::thread(&HardwareComposer::PostThread, this);
 
   initialized_ = true;
@@ -988,6 +1004,9 @@
       EnableDisplay(*external_display_, false);
     }
 
+    // Update the cached edid data for the current display.
+    UpdateEdidData(composer_.get(), target_display_->id);
+
     // Turn the new target display on.
     EnableDisplay(*target_display_, true);
 
diff --git a/libs/vr/libvrflinger/hardware_composer.h b/libs/vr/libvrflinger/hardware_composer.h
index db0d6a7..989ce35 100644
--- a/libs/vr/libvrflinger/hardware_composer.h
+++ b/libs/vr/libvrflinger/hardware_composer.h
@@ -25,6 +25,7 @@
 #include <private/dvr/shared_buffer_helpers.h>
 #include <private/dvr/vsync_service.h>
 
+#include "DisplayHardware/DisplayIdentification.h"
 #include "acquired_buffer.h"
 #include "display_surface.h"
 
@@ -334,6 +335,14 @@
   int OnNewGlobalBuffer(DvrGlobalBufferKey key, IonBuffer& ion_buffer);
   void OnDeletedGlobalBuffer(DvrGlobalBufferKey key);
 
+  // Gets the edid data for the current active display (internal or external)
+  DisplayIdentificationData GetCurrentDisplayIdentificationData() {
+    return display_identification_data_;
+  }
+
+  // Gets the edid port for the current active display (internal or external)
+  uint8_t GetCurrentDisplayPort() { return display_port_; }
+
  private:
   DisplayParams GetDisplayParams(Hwc2::Composer* composer,
       hwc2_display_t display, bool is_primary);
@@ -544,6 +553,11 @@
   bool vsync_trace_parity_ = false;
   sp<VsyncService> vsync_service_;
 
+  // Edid section.
+  void UpdateEdidData(Hwc2::Composer* composer, hwc2_display_t hw_id);
+  DisplayIdentificationData display_identification_data_;
+  uint8_t display_port_;
+
   static constexpr int kPostThreadInterrupted = 1;
 
   HardwareComposer(const HardwareComposer&) = delete;