diff --git a/services/surfaceflinger/DisplayHardware/HWC2.cpp b/services/surfaceflinger/DisplayHardware/HWC2.cpp
index bd5efc3..84f668d 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWC2.cpp
@@ -282,19 +282,28 @@
     return Error::NONE;
 }
 
-Error Display::getConnectionType(ui::DisplayConnectionType* outType) const {
-    if (mType != DisplayType::PHYSICAL) return Error::BAD_DISPLAY;
+ftl::Expected<ui::DisplayConnectionType, hal::Error> Display::getConnectionType() const {
+    if (!mConnectionType) {
+        mConnectionType = [this]() -> decltype(mConnectionType) {
+            if (mType != DisplayType::PHYSICAL) {
+                return ftl::Unexpected(Error::BAD_DISPLAY);
+            }
 
-    using ConnectionType = Hwc2::IComposerClient::DisplayConnectionType;
-    ConnectionType connectionType;
-    const auto error = static_cast<Error>(mComposer.getDisplayConnectionType(mId, &connectionType));
-    if (error != Error::NONE) {
-        return error;
+            using ConnectionType = Hwc2::IComposerClient::DisplayConnectionType;
+            ConnectionType connectionType;
+
+            if (const auto error = static_cast<Error>(
+                        mComposer.getDisplayConnectionType(mId, &connectionType));
+                error != Error::NONE) {
+                return ftl::Unexpected(error);
+            }
+
+            return connectionType == ConnectionType::INTERNAL ? ui::DisplayConnectionType::Internal
+                                                              : ui::DisplayConnectionType::External;
+        }();
     }
 
-    *outType = connectionType == ConnectionType::INTERNAL ? ui::DisplayConnectionType::Internal
-                                                          : ui::DisplayConnectionType::External;
-    return Error::NONE;
+    return *mConnectionType;
 }
 
 bool Display::hasCapability(DisplayCapability capability) const {
@@ -420,16 +429,11 @@
     // FIXME (b/319505580): At least the first config set on an external display must be
     // `setActiveConfig`, so skip over the block that calls `setActiveConfigWithConstraints`
     // for simplicity.
-    ui::DisplayConnectionType type = ui::DisplayConnectionType::Internal;
     const bool connected_display = FlagManager::getInstance().connected_display();
-    if (connected_display) {
-        // Do not bail out on error, since the underlying API may return UNSUPPORTED on older HWCs.
-        // TODO: b/323905961 - Remove this AIDL call.
-        getConnectionType(&type);
-    }
 
     if (isVsyncPeriodSwitchSupported() &&
-        (!connected_display || type != ui::DisplayConnectionType::External)) {
+        (!connected_display ||
+         getConnectionType().value_opt() != ui::DisplayConnectionType::External)) {
         Hwc2::IComposerClient::VsyncPeriodChangeConstraints hwc2Constraints;
         hwc2Constraints.desiredTimeNanos = constraints.desiredTimeNanos;
         hwc2Constraints.seamlessRequired = constraints.seamlessRequired;
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.h b/services/surfaceflinger/DisplayHardware/HWC2.h
index f907061..de044e0 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.h
+++ b/services/surfaceflinger/DisplayHardware/HWC2.h
@@ -18,6 +18,7 @@
 
 #include <android-base/expected.h>
 #include <android-base/thread_annotations.h>
+#include <ftl/expected.h>
 #include <ftl/future.h>
 #include <gui/HdrMetadata.h>
 #include <math/mat4.h>
@@ -120,7 +121,8 @@
     [[nodiscard]] virtual hal::Error getRequests(
             hal::DisplayRequest* outDisplayRequests,
             std::unordered_map<Layer*, hal::LayerRequest>* outLayerRequests) = 0;
-    [[nodiscard]] virtual hal::Error getConnectionType(ui::DisplayConnectionType*) const = 0;
+    [[nodiscard]] virtual ftl::Expected<ui::DisplayConnectionType, hal::Error> getConnectionType()
+            const = 0;
     [[nodiscard]] virtual hal::Error supportsDoze(bool* outSupport) const = 0;
     [[nodiscard]] virtual hal::Error getHdrCapabilities(
             android::HdrCapabilities* outCapabilities) const = 0;
@@ -213,7 +215,7 @@
     hal::Error getRequests(
             hal::DisplayRequest* outDisplayRequests,
             std::unordered_map<HWC2::Layer*, hal::LayerRequest>* outLayerRequests) override;
-    hal::Error getConnectionType(ui::DisplayConnectionType*) const override;
+    ftl::Expected<ui::DisplayConnectionType, hal::Error> getConnectionType() const override;
     hal::Error supportsDoze(bool* outSupport) const override EXCLUDES(mDisplayCapabilitiesMutex);
     hal::Error getHdrCapabilities(android::HdrCapabilities* outCapabilities) const override;
     hal::Error getOverlaySupport(aidl::android::hardware::graphics::composer3::OverlayProperties*
@@ -294,6 +296,8 @@
 
     const hal::HWDisplayId mId;
     hal::DisplayType mType;
+    // Cached on first call to getConnectionType.
+    mutable std::optional<ftl::Expected<ui::DisplayConnectionType, hal::Error>> mConnectionType;
     bool mIsConnected = false;
 
     using Layers = std::unordered_map<hal::HWLayerId, std::weak_ptr<HWC2::impl::Layer>>;
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index bac24c7..cfa0339 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -364,15 +364,13 @@
     RETURN_IF_INVALID_DISPLAY(displayId, ui::DisplayConnectionType::Internal);
     const auto& hwcDisplay = mDisplayData.at(displayId).hwcDisplay;
 
-    ui::DisplayConnectionType type;
-    const auto error = hwcDisplay->getConnectionType(&type);
-
-    const auto FALLBACK_TYPE = hwcDisplay->getId() == mPrimaryHwcDisplayId
-            ? ui::DisplayConnectionType::Internal
-            : ui::DisplayConnectionType::External;
-
-    RETURN_IF_HWC_ERROR(error, displayId, FALLBACK_TYPE);
-    return type;
+    if (const auto connectionType = hwcDisplay->getConnectionType()) {
+        return connectionType.value();
+    } else {
+        LOG_HWC_ERROR(__func__, connectionType.error(), displayId);
+        return hwcDisplay->getId() == mPrimaryHwcDisplayId ? ui::DisplayConnectionType::Internal
+                                                           : ui::DisplayConnectionType::External;
+    }
 }
 
 bool HWComposer::isVsyncPeriodSwitchSupported(PhysicalDisplayId displayId) const {
diff --git a/services/surfaceflinger/tests/unittests/HWComposerTest.cpp b/services/surfaceflinger/tests/unittests/HWComposerTest.cpp
index a25804c..2cff2f2 100644
--- a/services/surfaceflinger/tests/unittests/HWComposerTest.cpp
+++ b/services/surfaceflinger/tests/unittests/HWComposerTest.cpp
@@ -102,6 +102,29 @@
     ASSERT_TRUE(mHwc.isHeadless());
 }
 
+TEST_F(HWComposerTest, getDisplayConnectionType) {
+    // Unknown display.
+    EXPECT_EQ(mHwc.getDisplayConnectionType(PhysicalDisplayId::fromPort(0)),
+              ui::DisplayConnectionType::Internal);
+
+    constexpr hal::HWDisplayId kHwcDisplayId = 1;
+    expectHotplugConnect(kHwcDisplayId);
+
+    const auto info = mHwc.onHotplug(kHwcDisplayId, hal::Connection::CONNECTED);
+    ASSERT_TRUE(info);
+
+    EXPECT_CALL(*mHal, getDisplayConnectionType(kHwcDisplayId, _))
+            .WillOnce(DoAll(SetArgPointee<1>(IComposerClient::DisplayConnectionType::EXTERNAL),
+                            Return(V2_4::Error::NONE)));
+
+    // The first call caches the connection type.
+    EXPECT_EQ(mHwc.getDisplayConnectionType(info->id), ui::DisplayConnectionType::External);
+
+    // Subsequent calls return the cached connection type.
+    EXPECT_EQ(mHwc.getDisplayConnectionType(info->id), ui::DisplayConnectionType::External);
+    EXPECT_EQ(mHwc.getDisplayConnectionType(info->id), ui::DisplayConnectionType::External);
+}
+
 TEST_F(HWComposerTest, getActiveMode) {
     // Unknown display.
     EXPECT_EQ(mHwc.getActiveMode(PhysicalDisplayId::fromPort(0)), ftl::Unexpected(BAD_INDEX));
@@ -449,7 +472,7 @@
                                     {kMetadata1Name, kMetadata1Mandatory},
                                     {kMetadata2Name, kMetadata2Mandatory},
                             }),
-                            Return(hardware::graphics::composer::V2_4::Error::NONE)));
+                            Return(V2_4::Error::NONE)));
     EXPECT_CALL(*mHal, getOverlaySupport(_)).WillOnce(Return(HalError::NONE));
     EXPECT_CALL(*mHal, getHdrConversionCapabilities(_)).WillOnce(Return(HalError::NONE));
 
@@ -467,8 +490,7 @@
 
 TEST_F(HWComposerSetCallbackTest, handlesUnsupportedCallToGetLayerGenericMetadataKeys) {
     EXPECT_CALL(*mHal, getCapabilities()).WillOnce(Return(std::vector<aidl::Capability>{}));
-    EXPECT_CALL(*mHal, getLayerGenericMetadataKeys(_))
-            .WillOnce(Return(hardware::graphics::composer::V2_4::Error::UNSUPPORTED));
+    EXPECT_CALL(*mHal, getLayerGenericMetadataKeys(_)).WillOnce(Return(V2_4::Error::UNSUPPORTED));
     EXPECT_CALL(*mHal, getOverlaySupport(_)).WillOnce(Return(HalError::UNSUPPORTED));
     EXPECT_CALL(*mHal, getHdrConversionCapabilities(_)).WillOnce(Return(HalError::UNSUPPORTED));
     EXPECT_CALL(*mHal, registerCallback(_));
@@ -528,7 +550,7 @@
                 setLayerGenericMetadata(kDisplayId, kLayerId, kLayerGenericMetadata1Name,
                                         kLayerGenericMetadata1Mandatory,
                                         kLayerGenericMetadata1Value))
-            .WillOnce(Return(hardware::graphics::composer::V2_4::Error::NONE));
+            .WillOnce(Return(V2_4::Error::NONE));
     auto result = mLayer.setLayerGenericMetadata(kLayerGenericMetadata1Name,
                                                  kLayerGenericMetadata1Mandatory,
                                                  kLayerGenericMetadata1Value);
@@ -538,7 +560,7 @@
                 setLayerGenericMetadata(kDisplayId, kLayerId, kLayerGenericMetadata2Name,
                                         kLayerGenericMetadata2Mandatory,
                                         kLayerGenericMetadata2Value))
-            .WillOnce(Return(hardware::graphics::composer::V2_4::Error::UNSUPPORTED));
+            .WillOnce(Return(V2_4::Error::UNSUPPORTED));
     result = mLayer.setLayerGenericMetadata(kLayerGenericMetadata2Name,
                                             kLayerGenericMetadata2Mandatory,
                                             kLayerGenericMetadata2Value);
diff --git a/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockHWC2.h b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockHWC2.h
index 7413235..602bdfc 100644
--- a/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockHWC2.h
+++ b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockHWC2.h
@@ -53,7 +53,8 @@
     MOCK_METHOD(hal::Error, getRequests,
                 (hal::DisplayRequest *, (std::unordered_map<Layer *, hal::LayerRequest> *)),
                 (override));
-    MOCK_METHOD(hal::Error, getConnectionType, (ui::DisplayConnectionType *), (const, override));
+    MOCK_METHOD((ftl::Expected<ui::DisplayConnectionType, hal::Error>), getConnectionType, (),
+                (const, override));
     MOCK_METHOD(hal::Error, supportsDoze, (bool *), (const, override));
     MOCK_METHOD(hal::Error, getHdrCapabilities, (android::HdrCapabilities *), (const, override));
     MOCK_METHOD(hal::Error, getDisplayedContentSamplingAttributes,