diff --git a/services/inputflinger/tests/InputReader_test.cpp b/services/inputflinger/tests/InputReader_test.cpp
index 63bf633..56c1ade 100644
--- a/services/inputflinger/tests/InputReader_test.cpp
+++ b/services/inputflinger/tests/InputReader_test.cpp
@@ -2523,7 +2523,8 @@
     ASSERT_EQ(BTN_GEAR_UP, keyArgs.scanCode);
 }
 
-// --- TouchProcessTest ---
+// --- TouchIntegrationTest ---
+
 class TouchIntegrationTest : public InputReaderIntegrationTest {
 protected:
     const std::string UNIQUE_ID = "local:0";
@@ -2940,6 +2941,124 @@
                   WithToolType(AMOTION_EVENT_TOOL_TYPE_STYLUS), WithButtonState(0))));
 }
 
+// --- ExternalStylusIntegrationTest ---
+
+// Verify the behavior of an external stylus. An external stylus can report pressure or button
+// data independently of the touchscreen, which is then sent as a MotionEvent as part of an
+// ongoing stylus gesture that is being emitted by the touchscreen.
+using ExternalStylusIntegrationTest = TouchIntegrationTest;
+
+TEST_F(ExternalStylusIntegrationTest, FusedExternalStylusPressureReported) {
+    const Point centerPoint = mDevice->getCenterPoint();
+
+    // Create an external stylus capable of reporting pressure data that
+    // should be fused with a touch pointer.
+    std::unique_ptr<UinputExternalStylusWithPressure> stylus =
+            createUinputDevice<UinputExternalStylusWithPressure>();
+    ASSERT_NO_FATAL_FAILURE(mFakePolicy->assertInputDevicesChanged());
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyConfigurationChangedWasCalled());
+    const auto stylusInfo = findDeviceByName(stylus->getName());
+    ASSERT_TRUE(stylusInfo);
+
+    ASSERT_EQ(AINPUT_SOURCE_STYLUS | AINPUT_SOURCE_KEYBOARD, stylusInfo->getSources());
+
+    const auto touchscreenId = mDeviceInfo.getId();
+
+    // Set a pressure value on the stylus. It doesn't generate any events.
+    const auto& RAW_PRESSURE_MAX = UinputExternalStylusWithPressure::RAW_PRESSURE_MAX;
+    stylus->setPressure(100);
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasNotCalled());
+
+    // Start a finger gesture, and ensure it shows up as stylus gesture
+    // with the pressure set by the external stylus.
+    mDevice->sendSlot(FIRST_SLOT);
+    mDevice->sendTrackingId(FIRST_TRACKING_ID);
+    mDevice->sendToolType(MT_TOOL_FINGER);
+    mDevice->sendDown(centerPoint);
+    mDevice->sendSync();
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasCalled(
+            AllOf(WithMotionAction(AMOTION_EVENT_ACTION_DOWN),
+                  WithToolType(AMOTION_EVENT_TOOL_TYPE_STYLUS), WithButtonState(0),
+                  WithDeviceId(touchscreenId), WithPressure(100.f / RAW_PRESSURE_MAX))));
+
+    // Change the pressure on the external stylus, and ensure the touchscreen generates a MOVE
+    // event with the updated pressure.
+    stylus->setPressure(200);
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasCalled(
+            AllOf(WithMotionAction(AMOTION_EVENT_ACTION_MOVE),
+                  WithToolType(AMOTION_EVENT_TOOL_TYPE_STYLUS), WithButtonState(0),
+                  WithDeviceId(touchscreenId), WithPressure(200.f / RAW_PRESSURE_MAX))));
+
+    // The external stylus did not generate any events.
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasNotCalled());
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyKeyWasNotCalled());
+}
+
+TEST_F(ExternalStylusIntegrationTest, FusedExternalStylusPressureNotReported) {
+    const Point centerPoint = mDevice->getCenterPoint();
+
+    // Create an external stylus capable of reporting pressure data that
+    // should be fused with a touch pointer.
+    std::unique_ptr<UinputExternalStylusWithPressure> stylus =
+            createUinputDevice<UinputExternalStylusWithPressure>();
+    ASSERT_NO_FATAL_FAILURE(mFakePolicy->assertInputDevicesChanged());
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyConfigurationChangedWasCalled());
+    const auto stylusInfo = findDeviceByName(stylus->getName());
+    ASSERT_TRUE(stylusInfo);
+
+    ASSERT_EQ(AINPUT_SOURCE_STYLUS | AINPUT_SOURCE_KEYBOARD, stylusInfo->getSources());
+
+    const auto touchscreenId = mDeviceInfo.getId();
+
+    // Set a pressure value of 0 on the stylus. It doesn't generate any events.
+    const auto& RAW_PRESSURE_MAX = UinputExternalStylusWithPressure::RAW_PRESSURE_MAX;
+    stylus->setPressure(0);
+
+    // Start a finger gesture. The touch device will withhold generating any touches for
+    // up to 72 milliseconds while waiting for pressure data from the external stylus.
+    mDevice->sendSlot(FIRST_SLOT);
+    mDevice->sendTrackingId(FIRST_TRACKING_ID);
+    mDevice->sendToolType(MT_TOOL_FINGER);
+    mDevice->sendDown(centerPoint);
+    auto waitUntil = std::chrono::system_clock::now() +
+            std::chrono::milliseconds(ns2ms(EXTERNAL_STYLUS_DATA_TIMEOUT));
+    mDevice->sendSync();
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasNotCalled(waitUntil));
+
+    // Since the external stylus did not report a pressure value within the timeout,
+    // it shows up as a finger pointer.
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasCalled(
+            AllOf(WithMotionAction(AMOTION_EVENT_ACTION_DOWN),
+                  WithToolType(AMOTION_EVENT_TOOL_TYPE_FINGER), WithDeviceId(touchscreenId),
+                  WithPressure(1.f))));
+
+    // Change the pressure on the external stylus. Since the pressure was not present at the start
+    // of the gesture, it is ignored for now.
+    stylus->setPressure(200);
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasNotCalled());
+
+    // Finish the finger gesture.
+    mDevice->sendTrackingId(INVALID_TRACKING_ID);
+    mDevice->sendSync();
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasCalled(
+            AllOf(WithMotionAction(AMOTION_EVENT_ACTION_UP),
+                  WithToolType(AMOTION_EVENT_TOOL_TYPE_FINGER))));
+
+    // Start a new gesture. Since we have a valid pressure value, it shows up as a stylus.
+    mDevice->sendTrackingId(FIRST_TRACKING_ID);
+    mDevice->sendToolType(MT_TOOL_FINGER);
+    mDevice->sendDown(centerPoint);
+    mDevice->sendSync();
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasCalled(
+            AllOf(WithMotionAction(AMOTION_EVENT_ACTION_DOWN),
+                  WithToolType(AMOTION_EVENT_TOOL_TYPE_STYLUS), WithButtonState(0),
+                  WithDeviceId(touchscreenId), WithPressure(200.f / RAW_PRESSURE_MAX))));
+
+    // The external stylus did not generate any events.
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasNotCalled());
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyKeyWasNotCalled());
+}
+
 // --- InputDeviceTest ---
 class InputDeviceTest : public testing::Test {
 protected:
diff --git a/services/inputflinger/tests/TestInputListener.cpp b/services/inputflinger/tests/TestInputListener.cpp
index 5e47b80..a1299ee 100644
--- a/services/inputflinger/tests/TestInputListener.cpp
+++ b/services/inputflinger/tests/TestInputListener.cpp
@@ -82,9 +82,9 @@
     ASSERT_THAT(outEventArgs, matcher);
 }
 
-void TestInputListener::assertNotifyMotionWasNotCalled() {
+void TestInputListener::assertNotifyMotionWasNotCalled(std::optional<TimePoint> waitUntil) {
     ASSERT_NO_FATAL_FAILURE(
-            assertNotCalled<NotifyMotionArgs>("notifyMotion() should not be called."));
+            assertNotCalled<NotifyMotionArgs>("notifyMotion() should not be called.", waitUntil));
 }
 
 void TestInputListener::assertNotifySwitchWasCalled(NotifySwitchArgs* outEventArgs) {
@@ -139,14 +139,16 @@
 }
 
 template <class NotifyArgsType>
-void TestInputListener::assertNotCalled(std::string message) {
+void TestInputListener::assertNotCalled(std::string message, std::optional<TimePoint> waitUntil) {
     std::unique_lock<std::mutex> lock(mLock);
     base::ScopedLockAssertion assumeLocked(mLock);
 
     std::vector<NotifyArgsType>& queue = std::get<std::vector<NotifyArgsType>>(mQueues);
-    const bool eventReceived =
-            mCondition.wait_for(lock, mEventDidNotHappenTimeout,
-                                [&queue]() REQUIRES(mLock) { return !queue.empty(); });
+    const auto time =
+            waitUntil.value_or(std::chrono::system_clock::now() + mEventDidNotHappenTimeout);
+    const bool eventReceived = mCondition.wait_until(lock, time, [&queue]() REQUIRES(mLock) {
+        return !queue.empty();
+    });
     if (eventReceived) {
         FAIL() << "Unexpected event: " << message.c_str();
     }
diff --git a/services/inputflinger/tests/TestInputListener.h b/services/inputflinger/tests/TestInputListener.h
index 87752e1..c53f8e0 100644
--- a/services/inputflinger/tests/TestInputListener.h
+++ b/services/inputflinger/tests/TestInputListener.h
@@ -33,6 +33,8 @@
                       std::chrono::milliseconds eventDidNotHappenTimeout = 0ms);
     virtual ~TestInputListener();
 
+    using TimePoint = std::chrono::time_point<std::chrono::system_clock>;
+
     void assertNotifyConfigurationChangedWasCalled(
             NotifyConfigurationChangedArgs* outEventArgs = nullptr);
 
@@ -52,7 +54,7 @@
 
     void assertNotifyMotionWasCalled(const ::testing::Matcher<NotifyMotionArgs>& matcher);
 
-    void assertNotifyMotionWasNotCalled();
+    void assertNotifyMotionWasNotCalled(std::optional<TimePoint> waitUntil = {});
 
     void assertNotifySwitchWasCalled(NotifySwitchArgs* outEventArgs = nullptr);
 
@@ -66,7 +68,7 @@
     void assertCalled(NotifyArgsType* outEventArgs, std::string message);
 
     template <class NotifyArgsType>
-    void assertNotCalled(std::string message);
+    void assertNotCalled(std::string message, std::optional<TimePoint> timeout = {});
 
     template <class NotifyArgsType>
     void addToQueue(const NotifyArgsType* args);
diff --git a/services/inputflinger/tests/TestInputListenerMatchers.h b/services/inputflinger/tests/TestInputListenerMatchers.h
index 5470bee..438bb9a 100644
--- a/services/inputflinger/tests/TestInputListenerMatchers.h
+++ b/services/inputflinger/tests/TestInputListenerMatchers.h
@@ -55,6 +55,11 @@
     return arg.displayId == displayId;
 }
 
+MATCHER_P(WithDeviceId, deviceId, "InputEvent with specified deviceId") {
+    *result_listener << "expected deviceId " << deviceId << ", but got " << arg.deviceId;
+    return arg.deviceId == deviceId;
+}
+
 MATCHER_P(WithKeyCode, keyCode, "KeyEvent with specified key code") {
     *result_listener << "expected key code " << keyCode << ", but got " << arg.keyCode;
     return arg.keyCode == keyCode;
diff --git a/services/inputflinger/tests/UinputDevice.cpp b/services/inputflinger/tests/UinputDevice.cpp
index bc695b8..1051aa9 100644
--- a/services/inputflinger/tests/UinputDevice.cpp
+++ b/services/inputflinger/tests/UinputDevice.cpp
@@ -138,6 +138,25 @@
 UinputExternalStylus::UinputExternalStylus()
       : UinputKeyboard(DEVICE_NAME, PRODUCT_ID, {BTN_STYLUS, BTN_STYLUS2, BTN_STYLUS3}) {}
 
+// --- UinputExternalStylusWithPressure ---
+
+UinputExternalStylusWithPressure::UinputExternalStylusWithPressure()
+      : UinputKeyboard(DEVICE_NAME, PRODUCT_ID, {BTN_STYLUS, BTN_STYLUS2, BTN_STYLUS3}) {}
+
+void UinputExternalStylusWithPressure::configureDevice(int fd, uinput_user_dev* device) {
+    UinputKeyboard::configureDevice(fd, device);
+
+    ioctl(fd, UI_SET_EVBIT, EV_ABS);
+    ioctl(fd, UI_SET_ABSBIT, ABS_PRESSURE);
+    device->absmin[ABS_PRESSURE] = RAW_PRESSURE_MIN;
+    device->absmax[ABS_PRESSURE] = RAW_PRESSURE_MAX;
+}
+
+void UinputExternalStylusWithPressure::setPressure(int32_t pressure) {
+    injectEvent(EV_ABS, ABS_PRESSURE, pressure);
+    injectEvent(EV_SYN, SYN_REPORT, 0);
+}
+
 // --- UinputTouchScreen ---
 
 UinputTouchScreen::UinputTouchScreen(const Rect& size)
diff --git a/services/inputflinger/tests/UinputDevice.h b/services/inputflinger/tests/UinputDevice.h
index d661bd3..ad6125b 100644
--- a/services/inputflinger/tests/UinputDevice.h
+++ b/services/inputflinger/tests/UinputDevice.h
@@ -89,9 +89,9 @@
     explicit UinputKeyboard(const char* name, int16_t productId = PRODUCT_ID,
                             std::initializer_list<int> keys = {});
 
-private:
     void configureDevice(int fd, uinput_user_dev* device) override;
 
+private:
     std::set<int> mKeys;
 };
 
@@ -143,13 +143,35 @@
     explicit UinputExternalStylus();
 };
 
+// --- UinputExternalStylusWithPressure ---
+
+// A stylus that reports button presses and pressure values.
+class UinputExternalStylusWithPressure : public UinputKeyboard {
+public:
+    static constexpr const char* DEVICE_NAME = "Test Uinput External Stylus With Pressure";
+    static constexpr int16_t PRODUCT_ID = 46;
+
+    static constexpr int32_t RAW_PRESSURE_MIN = 0;
+    static constexpr int32_t RAW_PRESSURE_MAX = 255;
+
+    void setPressure(int32_t pressure);
+
+    template <class D, class... Ts>
+    friend std::unique_ptr<D> createUinputDevice(Ts... args);
+
+private:
+    void configureDevice(int fd, uinput_user_dev* device) override;
+
+    explicit UinputExternalStylusWithPressure();
+};
+
 // --- UinputTouchScreen ---
 
 // A multi-touch touchscreen device with specific size that also supports styluses.
 class UinputTouchScreen : public UinputDevice {
 public:
     static constexpr const char* DEVICE_NAME = "Test Uinput Touch Screen";
-    static constexpr int16_t PRODUCT_ID = 46;
+    static constexpr int16_t PRODUCT_ID = 47;
 
     static const int32_t RAW_TOUCH_MIN = 0;
     static const int32_t RAW_TOUCH_MAX = 31;