diff --git a/compatibility_matrices/compatibility_matrix.current.xml b/compatibility_matrices/compatibility_matrix.current.xml
index 76d1697..c920674 100644
--- a/compatibility_matrices/compatibility_matrix.current.xml
+++ b/compatibility_matrices/compatibility_matrix.current.xml
@@ -204,7 +204,7 @@
     </hal>
     <hal format="hidl" optional="false">
         <name>android.hardware.graphics.composer</name>
-        <version>2.1-3</version>
+        <version>2.1-4</version>
         <interface>
             <name>IComposer</name>
             <instance>default</instance>
diff --git a/graphics/composer/2.4/IComposer.hal b/graphics/composer/2.4/IComposer.hal
index 34801da..d3b3cb6 100644
--- a/graphics/composer/2.4/IComposer.hal
+++ b/graphics/composer/2.4/IComposer.hal
@@ -17,12 +17,10 @@
 package android.hardware.graphics.composer@2.4;
 
 import IComposerClient;
-
 import @2.1::Error;
 import @2.3::IComposer;
 
 interface IComposer extends @2.3::IComposer {
-
     /**
      * Creates a v2.4 client of the composer. Supersedes @2.3::createClient.
      *
diff --git a/graphics/composer/2.4/IComposerClient.hal b/graphics/composer/2.4/IComposerClient.hal
index 8fe0976..60445f5 100644
--- a/graphics/composer/2.4/IComposerClient.hal
+++ b/graphics/composer/2.4/IComposerClient.hal
@@ -21,13 +21,12 @@
 import @2.3::IComposerClient;
 
 interface IComposerClient extends @2.3::IComposerClient {
-
     /**
      * Required capabilities which are supported by the display. The
      * particular set of supported capabilities for a given display may be
      * retrieved using getDisplayCapabilities.
      */
-    enum DisplayCapability : uint32_t {
+    enum DisplayCapability : @2.3::IComposerClient.DisplayCapability {
         /**
          * Indicates that the display supports protected contents.
          * When returned, hardware composer must be able to accept client target
@@ -37,6 +36,20 @@
     };
 
     /**
+     * Supersedes {@link @2.1::IComposerClient.DisplayType}.
+     */
+    enum DisplayConnectionType : uint32_t {
+        /**
+         * Display is connected through internal port, e.g. DSI, eDP.
+         */
+        INTERNAL = 0,
+        /**
+         * Display is connected through external port, e.g. HDMI, DisplayPort.
+         */
+        EXTERNAL = 1,
+    };
+
+    /**
      * Provides a list of supported capabilities (as described in the
      * definition of DisplayCapability above). This list must not change after
      * initialization.
@@ -46,6 +59,14 @@
      * @return capabilities is a list of supported capabilities.
      */
     getDisplayCapabilities_2_4(Display display)
-              generates (Error error,
-                         vec<DisplayCapability> capabilities);
+        generates (Error error, vec<DisplayCapability> capabilities);
+
+    /**
+     * Returns whether the given physical display is internal or external.
+     *
+     * @return error is NONE upon success. Otherwise,
+     *     BAD_DISPLAY when the given display is invalid or virtual.
+     * @return type is the connection type of the display.
+     */
+    getDisplayConnectionType(Display display) generates (Error error, DisplayConnectionType type);
 };
diff --git a/graphics/composer/2.4/utils/hal/include/composer-hal/2.4/ComposerClient.h b/graphics/composer/2.4/utils/hal/include/composer-hal/2.4/ComposerClient.h
index 7110c80..c810186 100644
--- a/graphics/composer/2.4/utils/hal/include/composer-hal/2.4/ComposerClient.h
+++ b/graphics/composer/2.4/utils/hal/include/composer-hal/2.4/ComposerClient.h
@@ -46,6 +46,14 @@
         return Void();
     }
 
+    Return<void> getDisplayConnectionType(
+            Display display, IComposerClient::getDisplayConnectionType_cb hidl_cb) override {
+        IComposerClient::DisplayConnectionType type;
+        Error error = mHal->getDisplayConnectionType(display, &type);
+        hidl_cb(error, type);
+        return Void();
+    }
+
     static std::unique_ptr<ComposerClientImpl> create(Hal* hal) {
         auto client = std::make_unique<ComposerClientImpl>(hal);
         return client->init() ? std::move(client) : nullptr;
diff --git a/graphics/composer/2.4/utils/hal/include/composer-hal/2.4/ComposerHal.h b/graphics/composer/2.4/utils/hal/include/composer-hal/2.4/ComposerHal.h
index 0074808..c3bb535 100644
--- a/graphics/composer/2.4/utils/hal/include/composer-hal/2.4/ComposerHal.h
+++ b/graphics/composer/2.4/utils/hal/include/composer-hal/2.4/ComposerHal.h
@@ -38,6 +38,8 @@
   public:
     virtual Error getDisplayCapabilities_2_4(
             Display display, std::vector<IComposerClient::DisplayCapability>* outCapabilities) = 0;
+    virtual Error getDisplayConnectionType(Display display,
+                                           IComposerClient::DisplayConnectionType* outType) = 0;
 };
 
 }  // namespace hal
diff --git a/graphics/composer/2.4/utils/passthrough/include/composer-passthrough/2.4/HwcHal.h b/graphics/composer/2.4/utils/passthrough/include/composer-passthrough/2.4/HwcHal.h
index 65d47d7..fd05f66 100644
--- a/graphics/composer/2.4/utils/passthrough/include/composer-passthrough/2.4/HwcHal.h
+++ b/graphics/composer/2.4/utils/passthrough/include/composer-passthrough/2.4/HwcHal.h
@@ -62,15 +62,34 @@
         return Error::NONE;
     }
 
+    Error getDisplayConnectionType(Display display,
+                                   IComposerClient::DisplayConnectionType* outType) override {
+        if (!mDispatch.getDisplayConnectionType) {
+            return Error::UNSUPPORTED;
+        }
+
+        uint32_t type = HWC2_DISPLAY_CONNECTION_TYPE_INTERNAL;
+        int32_t error = mDispatch.getDisplayConnectionType(mDevice, display, &type);
+        *outType = static_cast<IComposerClient::DisplayConnectionType>(type);
+        return static_cast<Error>(error);
+    }
+
   protected:
     bool initDispatch() override {
         if (!BaseType2_3::initDispatch()) {
             return false;
         }
+
+        this->initOptionalDispatch(HWC2_FUNCTION_GET_DISPLAY_CONNECTION_TYPE,
+                                   &mDispatch.getDisplayConnectionType);
         return true;
     }
 
   private:
+    struct {
+        HWC2_PFN_GET_DISPLAY_CONNECTION_TYPE getDisplayConnectionType;
+    } mDispatch = {};
+
     using BaseType2_1 = V2_1::passthrough::detail::HwcHalImpl<Hal>;
     using BaseType2_3 = V2_3::passthrough::detail::HwcHalImpl<Hal>;
     using BaseType2_1::mDevice;
diff --git a/graphics/composer/2.4/utils/vts/ComposerVts.cpp b/graphics/composer/2.4/utils/vts/ComposerVts.cpp
index ee4f3a3..937b50e 100644
--- a/graphics/composer/2.4/utils/vts/ComposerVts.cpp
+++ b/graphics/composer/2.4/utils/vts/ComposerVts.cpp
@@ -51,7 +51,6 @@
 
 Error ComposerClient::getDisplayCapabilities(
         Display display, std::vector<IComposerClient::DisplayCapability>* outCapabilities) {
-    std::vector<IComposerClient::DisplayCapability> capabilities;
     Error error = Error::NONE;
     mClient->getDisplayCapabilities_2_4(display,
                                         [&](const auto& tmpError, const auto& tmpCapabilities) {
@@ -61,6 +60,16 @@
     return error;
 }
 
+Error ComposerClient::getDisplayConnectionType(Display display,
+                                               IComposerClient::DisplayConnectionType* outType) {
+    Error error = Error::NONE;
+    mClient->getDisplayConnectionType(display, [&](const auto& tmpError, const auto& tmpType) {
+        error = tmpError;
+        *outType = tmpType;
+    });
+    return error;
+}
+
 }  // namespace vts
 }  // namespace V2_4
 }  // namespace composer
diff --git a/graphics/composer/2.4/utils/vts/include/composer-vts/2.4/ComposerVts.h b/graphics/composer/2.4/utils/vts/include/composer-vts/2.4/ComposerVts.h
index 0a301c6..a7d7f86 100644
--- a/graphics/composer/2.4/utils/vts/include/composer-vts/2.4/ComposerVts.h
+++ b/graphics/composer/2.4/utils/vts/include/composer-vts/2.4/ComposerVts.h
@@ -71,6 +71,9 @@
             Display display,
             std::vector<IComposerClient::DisplayCapability>* outDisplayCapabilities);
 
+    Error getDisplayConnectionType(Display display,
+                                   IComposerClient::DisplayConnectionType* outType);
+
   private:
     const sp<IComposerClient> mClient;
 };
diff --git a/graphics/composer/2.4/vts/functional/VtsHalGraphicsComposerV2_4TargetTest.cpp b/graphics/composer/2.4/vts/functional/VtsHalGraphicsComposerV2_4TargetTest.cpp
index 0fccc58..76c0039 100644
--- a/graphics/composer/2.4/vts/functional/VtsHalGraphicsComposerV2_4TargetTest.cpp
+++ b/graphics/composer/2.4/vts/functional/VtsHalGraphicsComposerV2_4TargetTest.cpp
@@ -179,6 +179,16 @@
     EXPECT_EQ(Error::BAD_DISPLAY, error);
 }
 
+TEST_F(GraphicsComposerHidlTest, getDisplayConnectionType) {
+    IComposerClient::DisplayConnectionType type;
+    EXPECT_EQ(Error::BAD_DISPLAY,
+              mComposerClient->getDisplayConnectionType(mInvalidDisplayId, &type));
+
+    for (Display display : mComposerCallback->getDisplays()) {
+        EXPECT_EQ(Error::NONE, mComposerClient->getDisplayConnectionType(display, &type));
+    }
+}
+
 }  // namespace
 }  // namespace vts
 }  // namespace V2_4