diff --git a/include/input/PrintTools.h b/include/input/PrintTools.h
new file mode 100644
index 0000000..7c3b29b
--- /dev/null
+++ b/include/input/PrintTools.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+#pragma once
+
+#include <map>
+#include <set>
+#include <string>
+
+namespace android {
+
+template <typename T>
+std::string constToString(const T& v) {
+    return std::to_string(v);
+}
+
+/**
+ * Convert a set of integral types to string.
+ */
+template <typename T>
+std::string dumpSet(const std::set<T>& v, std::string (*toString)(const T&) = constToString) {
+    std::string out;
+    for (const T& entry : v) {
+        out += out.empty() ? "{" : ", ";
+        out += toString(entry);
+    }
+    return out.empty() ? "{}" : (out + "}");
+}
+
+/**
+ * Convert a map to string. Both keys and values of the map should be integral type.
+ */
+template <typename K, typename V>
+std::string dumpMap(const std::map<K, V>& map, std::string (*keyToString)(const K&) = constToString,
+                    std::string (*valueToString)(const V&) = constToString) {
+    std::string out;
+    for (const auto& [k, v] : map) {
+        if (!out.empty()) {
+            out += "\n";
+        }
+        out += keyToString(k) + ":" + valueToString(v);
+    }
+    return out;
+}
+
+const char* toString(bool value);
+
+} // namespace android
\ No newline at end of file
diff --git a/libs/input/Android.bp b/libs/input/Android.bp
index 18fb7c1..1d4fc1f 100644
--- a/libs/input/Android.bp
+++ b/libs/input/Android.bp
@@ -50,6 +50,7 @@
         "Keyboard.cpp",
         "KeyCharacterMap.cpp",
         "KeyLayoutMap.cpp",
+        "PrintTools.cpp",
         "PropertyMap.cpp",
         "TouchVideoFrame.cpp",
         "VelocityControl.cpp",
@@ -102,6 +103,9 @@
 
             sanitize: {
                 misc_undefined: ["integer"],
+                diag: {
+                    misc_undefined: ["integer"],
+                },
             },
         },
         host: {
diff --git a/libs/input/PrintTools.cpp b/libs/input/PrintTools.cpp
new file mode 100644
index 0000000..5d6ae4e
--- /dev/null
+++ b/libs/input/PrintTools.cpp
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2022 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 "PrintTools"
+
+#include <input/PrintTools.h>
+
+namespace android {
+
+const char* toString(bool value) {
+    return value ? "true" : "false";
+}
+
+} // namespace android
diff --git a/services/inputflinger/InputListener.cpp b/services/inputflinger/InputListener.cpp
index 3a4b6c5..2a3924b 100644
--- a/services/inputflinger/InputListener.cpp
+++ b/services/inputflinger/InputListener.cpp
@@ -202,9 +202,11 @@
         coords += "}";
     }
     return StringPrintf("NotifyMotionArgs(id=%" PRId32 ", eventTime=%" PRId64 ", deviceId=%" PRId32
-                        ", source=%s, action=%s, pointerCount=%" PRIu32 " pointers=%s)",
+                        ", source=%s, action=%s, pointerCount=%" PRIu32
+                        " pointers=%s, flags=0x%08x)",
                         id, eventTime, deviceId, inputEventSourceToString(source).c_str(),
-                        MotionEvent::actionToString(action).c_str(), pointerCount, coords.c_str());
+                        MotionEvent::actionToString(action).c_str(), pointerCount, coords.c_str(),
+                        flags);
 }
 
 void NotifyMotionArgs::notify(InputListenerInterface& listener) const {
diff --git a/services/inputflinger/PreferStylusOverTouchBlocker.cpp b/services/inputflinger/PreferStylusOverTouchBlocker.cpp
index ad639b4..beec2e1 100644
--- a/services/inputflinger/PreferStylusOverTouchBlocker.cpp
+++ b/services/inputflinger/PreferStylusOverTouchBlocker.cpp
@@ -15,78 +15,163 @@
  */
 
 #include "PreferStylusOverTouchBlocker.h"
-
-#include <android-base/stringprintf.h>
-
-using android::base::StringPrintf;
-
-static const char* toString(bool value) {
-    return value ? "true" : "false";
-}
+#include <input/PrintTools.h>
 
 namespace android {
 
-ftl::StaticVector<NotifyMotionArgs, 2> PreferStylusOverTouchBlocker::processMotion(
-        const NotifyMotionArgs& args) {
-    const bool isStylusEvent = isFromSource(args.source, AINPUT_SOURCE_STYLUS);
-    if (isStylusEvent) {
-        for (size_t i = 0; i < args.pointerCount; i++) {
-            // Make sure we are canceling stylus pointers
-            const int32_t toolType = args.pointerProperties[i].toolType;
-            LOG_ALWAYS_FATAL_IF(toolType != AMOTION_EVENT_TOOL_TYPE_STYLUS &&
-                                        toolType != AMOTION_EVENT_TOOL_TYPE_ERASER,
-                                "The pointer %zu has toolType=%i, but the source is STYLUS. If "
-                                "simultaneous touch and stylus is supported, "
-                                "'PreferStylusOverTouchBlocker' should be disabled.",
-                                i, toolType);
+static std::pair<bool, bool> checkToolType(const NotifyMotionArgs& args) {
+    bool hasStylus = false;
+    bool hasTouch = false;
+    for (size_t i = 0; i < args.pointerCount; i++) {
+        // Make sure we are canceling stylus pointers
+        const int32_t toolType = args.pointerProperties[i].toolType;
+        if (toolType == AMOTION_EVENT_TOOL_TYPE_STYLUS ||
+            toolType == AMOTION_EVENT_TOOL_TYPE_ERASER) {
+            hasStylus = true;
+        }
+        if (toolType == AMOTION_EVENT_TOOL_TYPE_FINGER) {
+            hasTouch = true;
         }
     }
-    const bool isDown = args.action == AMOTION_EVENT_ACTION_DOWN;
+    return std::make_pair(hasTouch, hasStylus);
+}
+
+/**
+ * Intersect two sets in-place, storing the result in 'set1'.
+ * Find elements in set1 that are not present in set2 and delete them,
+ * relying on the fact that the two sets are ordered.
+ */
+template <typename T>
+static void intersectInPlace(std::set<T>& set1, const std::set<T>& set2) {
+    typename std::set<T>::iterator it1 = set1.begin();
+    typename std::set<T>::const_iterator it2 = set2.begin();
+    while (it1 != set1.end() && it2 != set2.end()) {
+        const T& element1 = *it1;
+        const T& element2 = *it2;
+        if (element1 < element2) {
+            // This element is not present in set2. Remove it from set1.
+            it1 = set1.erase(it1);
+            continue;
+        }
+        if (element2 < element1) {
+            it2++;
+        }
+        if (element1 == element2) {
+            it1++;
+            it2++;
+        }
+    }
+    // Remove the rest of the elements in set1 because set2 is already exhausted.
+    set1.erase(it1, set1.end());
+}
+
+/**
+ * Same as above, but prune a map
+ */
+template <typename K, class V>
+static void intersectInPlace(std::map<K, V>& map, const std::set<K>& set2) {
+    typename std::map<K, V>::iterator it1 = map.begin();
+    typename std::set<K>::const_iterator it2 = set2.begin();
+    while (it1 != map.end() && it2 != set2.end()) {
+        const auto& [key, _] = *it1;
+        const K& element2 = *it2;
+        if (key < element2) {
+            // This element is not present in set2. Remove it from map.
+            it1 = map.erase(it1);
+            continue;
+        }
+        if (element2 < key) {
+            it2++;
+        }
+        if (key == element2) {
+            it1++;
+            it2++;
+        }
+    }
+    // Remove the rest of the elements in map because set2 is already exhausted.
+    map.erase(it1, map.end());
+}
+
+// -------------------------------- PreferStylusOverTouchBlocker -----------------------------------
+
+std::vector<NotifyMotionArgs> PreferStylusOverTouchBlocker::processMotion(
+        const NotifyMotionArgs& args) {
+    const auto [hasTouch, hasStylus] = checkToolType(args);
     const bool isUpOrCancel =
             args.action == AMOTION_EVENT_ACTION_UP || args.action == AMOTION_EVENT_ACTION_CANCEL;
+
+    if (hasTouch && hasStylus) {
+        mDevicesWithMixedToolType.insert(args.deviceId);
+    }
+    // Handle the case where mixed touch and stylus pointers are reported. Add this device to the
+    // ignore list, since it clearly supports simultaneous touch and stylus.
+    if (mDevicesWithMixedToolType.find(args.deviceId) != mDevicesWithMixedToolType.end()) {
+        // This event comes from device with mixed stylus and touch event. Ignore this device.
+        if (mCanceledDevices.find(args.deviceId) != mCanceledDevices.end()) {
+            // If we started to cancel events from this device, continue to do so to keep
+            // the stream consistent. It should happen at most once per "mixed" device.
+            if (isUpOrCancel) {
+                mCanceledDevices.erase(args.deviceId);
+                mLastTouchEvents.erase(args.deviceId);
+            }
+            return {};
+        }
+        return {args};
+    }
+
+    const bool isStylusEvent = hasStylus;
+    const bool isDown = args.action == AMOTION_EVENT_ACTION_DOWN;
+
     if (isStylusEvent) {
         if (isDown) {
             // Reject all touch while stylus is down
-            mIsStylusDown = true;
-            if (mIsTouchDown && !mCurrentTouchIsCanceled) {
-                // Cancel touch!
-                mCurrentTouchIsCanceled = true;
-                mLastTouchEvent.action = AMOTION_EVENT_ACTION_CANCEL;
-                mLastTouchEvent.flags |= AMOTION_EVENT_FLAG_CANCELED;
-                mLastTouchEvent.eventTime = systemTime(SYSTEM_TIME_MONOTONIC);
-                return {mLastTouchEvent, args};
+            mActiveStyli.insert(args.deviceId);
+
+            // Cancel all current touch!
+            std::vector<NotifyMotionArgs> result;
+            for (auto& [deviceId, lastTouchEvent] : mLastTouchEvents) {
+                if (mCanceledDevices.find(deviceId) != mCanceledDevices.end()) {
+                    // Already canceled, go to next one.
+                    continue;
+                }
+                // Not yet canceled. Cancel it.
+                lastTouchEvent.action = AMOTION_EVENT_ACTION_CANCEL;
+                lastTouchEvent.flags |= AMOTION_EVENT_FLAG_CANCELED;
+                lastTouchEvent.eventTime = systemTime(SYSTEM_TIME_MONOTONIC);
+                result.push_back(lastTouchEvent);
+                mCanceledDevices.insert(deviceId);
             }
+            result.push_back(args);
+            return result;
         }
         if (isUpOrCancel) {
-            mIsStylusDown = false;
+            mActiveStyli.erase(args.deviceId);
         }
         // Never drop stylus events
         return {args};
     }
 
-    const bool isTouchEvent =
-            isFromSource(args.source, AINPUT_SOURCE_TOUCHSCREEN) && !isStylusEvent;
+    const bool isTouchEvent = hasTouch;
     if (isTouchEvent) {
-        if (mIsStylusDown) {
-            mCurrentTouchIsCanceled = true;
+        // Suppress the current gesture if any stylus is still down
+        if (!mActiveStyli.empty()) {
+            mCanceledDevices.insert(args.deviceId);
         }
+
+        const bool shouldDrop = mCanceledDevices.find(args.deviceId) != mCanceledDevices.end();
+        if (isUpOrCancel) {
+            mCanceledDevices.erase(args.deviceId);
+            mLastTouchEvents.erase(args.deviceId);
+        }
+
         // If we already canceled the current gesture, then continue to drop events from it, even if
         // the stylus has been lifted.
-        if (mCurrentTouchIsCanceled) {
-            if (isUpOrCancel) {
-                mCurrentTouchIsCanceled = false;
-            }
+        if (shouldDrop) {
             return {};
         }
 
-        // Update state
-        mLastTouchEvent = args;
-        if (isDown) {
-            mIsTouchDown = true;
-        }
-        if (isUpOrCancel) {
-            mIsTouchDown = false;
-            mCurrentTouchIsCanceled = false;
+        if (!isUpOrCancel) {
+            mLastTouchEvents[args.deviceId] = args;
         }
         return {args};
     }
@@ -95,12 +180,36 @@
     return {args};
 }
 
-std::string PreferStylusOverTouchBlocker::dump() {
+void PreferStylusOverTouchBlocker::notifyInputDevicesChanged(
+        const std::vector<InputDeviceInfo>& inputDevices) {
+    std::set<int32_t> presentDevices;
+    for (const InputDeviceInfo& device : inputDevices) {
+        presentDevices.insert(device.getId());
+    }
+    // Only keep the devices that are still present.
+    intersectInPlace(mDevicesWithMixedToolType, presentDevices);
+    intersectInPlace(mLastTouchEvents, presentDevices);
+    intersectInPlace(mCanceledDevices, presentDevices);
+    intersectInPlace(mActiveStyli, presentDevices);
+}
+
+void PreferStylusOverTouchBlocker::notifyDeviceReset(const NotifyDeviceResetArgs& args) {
+    mDevicesWithMixedToolType.erase(args.deviceId);
+    mLastTouchEvents.erase(args.deviceId);
+    mCanceledDevices.erase(args.deviceId);
+    mActiveStyli.erase(args.deviceId);
+}
+
+static std::string dumpArgs(const NotifyMotionArgs& args) {
+    return args.dump();
+}
+
+std::string PreferStylusOverTouchBlocker::dump() const {
     std::string out;
-    out += StringPrintf("mIsTouchDown: %s\n", toString(mIsTouchDown));
-    out += StringPrintf("mIsStylusDown: %s\n", toString(mIsStylusDown));
-    out += StringPrintf("mLastTouchEvent: %s\n", mLastTouchEvent.dump().c_str());
-    out += StringPrintf("mCurrentTouchIsCanceled: %s\n", toString(mCurrentTouchIsCanceled));
+    out += "mActiveStyli: " + dumpSet(mActiveStyli) + "\n";
+    out += "mLastTouchEvents: " + dumpMap(mLastTouchEvents, constToString, dumpArgs) + "\n";
+    out += "mDevicesWithMixedToolType: " + dumpSet(mDevicesWithMixedToolType) + "\n";
+    out += "mCanceledDevices: " + dumpSet(mCanceledDevices) + "\n";
     return out;
 }
 
diff --git a/services/inputflinger/PreferStylusOverTouchBlocker.h b/services/inputflinger/PreferStylusOverTouchBlocker.h
index 3f56161..716dc4d 100644
--- a/services/inputflinger/PreferStylusOverTouchBlocker.h
+++ b/services/inputflinger/PreferStylusOverTouchBlocker.h
@@ -16,66 +16,50 @@
 
 #pragma once
 
-#include <ftl/static_vector.h>
 #include <optional>
+#include <set>
 #include "InputListener.h"
 
 namespace android {
 
 /**
- * When stylus is down, we ignore all touch.
+ * When stylus is down, all touch is ignored.
  * TODO(b/210159205): delete this when simultaneous stylus and touch is supported
  */
 class PreferStylusOverTouchBlocker {
 public:
     /**
-     * Process the provided event and emit up to 2 events in response.
+     * Process the provided event and emit 0 or more events that should be used instead of it.
      * In the majority of cases, the returned result will just be the provided args (array with
      * only 1 element), unmodified.
      *
      * If the gesture should be blocked, the returned result may be:
      *
      * a) An empty array, if the current event should just be ignored completely
-     * b) An array of 2 elements, containing an event with ACTION_CANCEL and the current event.
+     * b) An array of N elements, containing N-1 events with ACTION_CANCEL and the current event.
      *
-     * bool is set to 'true'.
-     * NotifyMotionArgs potentially contains an event that should be used to cancel the existing
-     * gesture.
-     *
-     * If the event should not be blocked, bool contains 'false'.
+     * The returned result is intended to be reinjected into the original event stream in
+     * replacement of the incoming event.
      */
-    ftl::StaticVector<NotifyMotionArgs, 2> processMotion(const NotifyMotionArgs& args);
-    std::string dump();
+    std::vector<NotifyMotionArgs> processMotion(const NotifyMotionArgs& args);
+    std::string dump() const;
+
+    void notifyInputDevicesChanged(const std::vector<InputDeviceInfo>& inputDevices);
+
+    void notifyDeviceReset(const NotifyDeviceResetArgs& args);
 
 private:
-    bool mIsTouchDown = false;
-    bool mIsStylusDown = false;
-    // Provide some default values for the stored MotionEvent to allow printint the event before
-    // any real event is received.
-    NotifyMotionArgs mLastTouchEvent{0 /*id*/,
-                                     0 /*eventTime*/,
-                                     0 /*readTime*/,
-                                     0 /*deviceId*/,
-                                     AINPUT_SOURCE_TOUCHSCREEN,
-                                     0 /*displayId*/,
-                                     0 /*policyFlags*/,
-                                     0 /*action*/,
-                                     0 /*actionButton*/,
-                                     0 /*flags*/,
-                                     0 /*metaState*/,
-                                     0 /*buttonState*/,
-                                     MotionClassification::NONE,
-                                     AMOTION_EVENT_EDGE_FLAG_NONE,
-                                     0 /*pointerCount*/,
-                                     nullptr /*properties*/,
-                                     nullptr /*coords*/,
-                                     0. /*xPrecision*/,
-                                     0. /*yPrecision*/,
-                                     AMOTION_EVENT_INVALID_CURSOR_POSITION,
-                                     AMOTION_EVENT_INVALID_CURSOR_POSITION,
-                                     0 /*downTime*/,
-                                     {}};
-    bool mCurrentTouchIsCanceled = false;
+    // Stores the device id's of styli that are currently down.
+    std::set<int32_t /*deviceId*/> mActiveStyli;
+    // For each device, store the last touch event as long as the touch is down. Upon liftoff,
+    // the entry is erased.
+    std::map<int32_t /*deviceId*/, NotifyMotionArgs> mLastTouchEvents;
+    // Device ids of devices for which the current touch gesture is canceled.
+    std::set<int32_t /*deviceId*/> mCanceledDevices;
+
+    // Device ids of input devices where we encountered simultaneous touch and stylus
+    // events. For these devices, we don't do any event processing (nothing is blocked or altered).
+    std::set<int32_t /*deviceId*/> mDevicesWithMixedToolType;
 };
 
 } // namespace android
\ No newline at end of file
diff --git a/services/inputflinger/UnwantedInteractionBlocker.cpp b/services/inputflinger/UnwantedInteractionBlocker.cpp
index fb3962e..b69e16a 100644
--- a/services/inputflinger/UnwantedInteractionBlocker.cpp
+++ b/services/inputflinger/UnwantedInteractionBlocker.cpp
@@ -368,6 +368,14 @@
 }
 
 void UnwantedInteractionBlocker::notifyMotion(const NotifyMotionArgs* args) {
+    const std::vector<NotifyMotionArgs> processedArgs =
+            mPreferStylusOverTouchBlocker.processMotion(*args);
+    for (const NotifyMotionArgs& loopArgs : processedArgs) {
+        notifyMotionInner(&loopArgs);
+    }
+}
+
+void UnwantedInteractionBlocker::notifyMotionInner(const NotifyMotionArgs* args) {
     auto it = mPalmRejectors.find(args->deviceId);
     const bool sendToPalmRejector = it != mPalmRejectors.end() && isFromTouchscreen(args->source);
     if (!sendToPalmRejector) {
@@ -401,6 +409,7 @@
         mPalmRejectors.emplace(args->deviceId, info);
     }
     mListener.notifyDeviceReset(args);
+    mPreferStylusOverTouchBlocker.notifyDeviceReset(*args);
 }
 
 void UnwantedInteractionBlocker::notifyPointerCaptureChanged(
@@ -437,10 +446,13 @@
         auto const& [deviceId, _] = item;
         return devicesToKeep.find(deviceId) == devicesToKeep.end();
     });
+    mPreferStylusOverTouchBlocker.notifyInputDevicesChanged(inputDevices);
 }
 
 void UnwantedInteractionBlocker::dump(std::string& dump) {
     dump += "UnwantedInteractionBlocker:\n";
+    dump += "  mPreferStylusOverTouchBlocker:\n";
+    dump += addPrefix(mPreferStylusOverTouchBlocker.dump(), "    ");
     dump += StringPrintf("  mEnablePalmRejection: %s\n", toString(mEnablePalmRejection));
     dump += StringPrintf("  isPalmRejectionEnabled (flag value): %s\n",
                          toString(isPalmRejectionEnabled()));
diff --git a/services/inputflinger/UnwantedInteractionBlocker.h b/services/inputflinger/UnwantedInteractionBlocker.h
index 14068fd..8a1cd72 100644
--- a/services/inputflinger/UnwantedInteractionBlocker.h
+++ b/services/inputflinger/UnwantedInteractionBlocker.h
@@ -23,6 +23,8 @@
 #include "ui/events/ozone/evdev/touch_filter/neural_stylus_palm_detection_filter_util.h"
 #include "ui/events/ozone/evdev/touch_filter/palm_detection_filter.h"
 
+#include "PreferStylusOverTouchBlocker.h"
+
 namespace android {
 
 // --- Functions for manipulation of event streams
@@ -88,9 +90,14 @@
     InputListenerInterface& mListener;
     const bool mEnablePalmRejection;
 
+    // When stylus is down, ignore touch
+    PreferStylusOverTouchBlocker mPreferStylusOverTouchBlocker;
+
     // Detect and reject unwanted palms on screen
     // Use a separate palm rejector for every touch device.
     std::map<int32_t /*deviceId*/, PalmRejector> mPalmRejectors;
+    // TODO(b/210159205): delete this when simultaneous stylus and touch is supported
+    void notifyMotionInner(const NotifyMotionArgs* args);
 };
 
 class SlotState {
diff --git a/services/inputflinger/tests/PreferStylusOverTouch_test.cpp b/services/inputflinger/tests/PreferStylusOverTouch_test.cpp
index 70f40aa..8e2ab88 100644
--- a/services/inputflinger/tests/PreferStylusOverTouch_test.cpp
+++ b/services/inputflinger/tests/PreferStylusOverTouch_test.cpp
@@ -20,12 +20,16 @@
 namespace android {
 
 constexpr int32_t TOUCH_DEVICE_ID = 3;
-constexpr int32_t STYLUS_DEVICE_ID = 4;
+constexpr int32_t SECOND_TOUCH_DEVICE_ID = 4;
+constexpr int32_t STYLUS_DEVICE_ID = 5;
+constexpr int32_t SECOND_STYLUS_DEVICE_ID = 6;
 
 constexpr int DOWN = AMOTION_EVENT_ACTION_DOWN;
 constexpr int MOVE = AMOTION_EVENT_ACTION_MOVE;
 constexpr int UP = AMOTION_EVENT_ACTION_UP;
 constexpr int CANCEL = AMOTION_EVENT_ACTION_CANCEL;
+static constexpr int32_t POINTER_1_DOWN =
+        AMOTION_EVENT_ACTION_POINTER_DOWN | (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT);
 constexpr int32_t TOUCHSCREEN = AINPUT_SOURCE_TOUCHSCREEN;
 constexpr int32_t STYLUS = AINPUT_SOURCE_STYLUS;
 
@@ -78,29 +82,30 @@
 
 class PreferStylusOverTouchTest : public testing::Test {
 protected:
-    void assertNotBlocked(const NotifyMotionArgs& args) {
-        ftl::StaticVector<NotifyMotionArgs, 2> processedArgs = mBlocker.processMotion(args);
-        ASSERT_EQ(1u, processedArgs.size());
-        ASSERT_EQ(args, processedArgs[0]);
+    void assertNotBlocked(const NotifyMotionArgs& args) { assertResponse(args, {args}); }
+
+    void assertDropped(const NotifyMotionArgs& args) { assertResponse(args, {}); }
+
+    void assertResponse(const NotifyMotionArgs& args,
+                        const std::vector<NotifyMotionArgs>& expected) {
+        std::vector<NotifyMotionArgs> receivedArgs = mBlocker.processMotion(args);
+        ASSERT_EQ(expected.size(), receivedArgs.size());
+        for (size_t i = 0; i < expected.size(); i++) {
+            // The 'eventTime' of CANCEL events is dynamically generated. Don't check this field.
+            if (expected[i].action == CANCEL && receivedArgs[i].action == CANCEL) {
+                receivedArgs[i].eventTime = expected[i].eventTime;
+            }
+
+            ASSERT_EQ(expected[i], receivedArgs[i])
+                    << expected[i].dump() << " vs " << receivedArgs[i].dump();
+        }
     }
 
-    void assertDropped(const NotifyMotionArgs& args) {
-        ftl::StaticVector<NotifyMotionArgs, 2> processedArgs = mBlocker.processMotion(args);
-        ASSERT_TRUE(processedArgs.empty());
+    void notifyInputDevicesChanged(const std::vector<InputDeviceInfo>& devices) {
+        mBlocker.notifyInputDevicesChanged(devices);
     }
 
-    void assertCanceled(const NotifyMotionArgs& args,
-                        std::optional<NotifyMotionArgs> canceledArgs) {
-        ftl::StaticVector<NotifyMotionArgs, 2> processedArgs = mBlocker.processMotion(args);
-        ASSERT_EQ(2u, processedArgs.size());
-        NotifyMotionArgs& cancelEvent = processedArgs[0];
-        ASSERT_EQ(CANCEL, cancelEvent.action);
-        ASSERT_EQ(AMOTION_EVENT_FLAG_CANCELED, cancelEvent.flags & AMOTION_EVENT_FLAG_CANCELED);
-        ASSERT_TRUE(isFromSource(cancelEvent.source, TOUCHSCREEN));
-        ASSERT_FALSE(isFromSource(cancelEvent.source, STYLUS));
-
-        ASSERT_EQ(args, processedArgs[1]);
-    }
+    void dump() const { ALOGI("Blocker: \n%s\n", mBlocker.dump().c_str()); }
 
 private:
     PreferStylusOverTouchBlocker mBlocker;
@@ -148,7 +153,8 @@
     args = generateMotionArgs(3 /*downTime*/, 3 /*eventTime*/, DOWN, {{10, 30}}, STYLUS);
     NotifyMotionArgs cancelArgs =
             generateMotionArgs(0 /*downTime*/, 1 /*eventTime*/, CANCEL, {{1, 3}}, TOUCHSCREEN);
-    assertCanceled(args, cancelArgs);
+    cancelArgs.flags |= AMOTION_EVENT_FLAG_CANCELED;
+    assertResponse(args, {cancelArgs, args});
 
     // Both stylus and touch events continue. Stylus should be not blocked, and touch should be
     // blocked
@@ -160,6 +166,26 @@
 }
 
 /**
+ * Stylus goes down after touch gesture.
+ */
+TEST_F(PreferStylusOverTouchTest, StylusDownAfterTouch) {
+    NotifyMotionArgs args;
+
+    args = generateMotionArgs(0 /*downTime*/, 0 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(0 /*downTime*/, 1 /*eventTime*/, MOVE, {{1, 3}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(0 /*downTime*/, 2 /*eventTime*/, UP, {{1, 3}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+
+    // Stylus goes down
+    args = generateMotionArgs(3 /*downTime*/, 3 /*eventTime*/, DOWN, {{10, 30}}, STYLUS);
+    assertNotBlocked(args);
+}
+
+/**
  * New touch events should be simply blocked (dropped) when stylus is down. No CANCEL event should
  * be generated.
  */
@@ -247,4 +273,230 @@
     assertNotBlocked(args);
 }
 
+/**
+ * If an event with mixed stylus and touch pointers is encountered, it should be ignored. Touches
+ * from such should pass, even if stylus from the same device goes down.
+ */
+TEST_F(PreferStylusOverTouchTest, MixedStylusAndTouchPointersAreIgnored) {
+    NotifyMotionArgs args;
+
+    // Event from a stylus device, but with finger tool type
+    args = generateMotionArgs(1 /*downTime*/, 1 /*eventTime*/, DOWN, {{1, 2}}, STYLUS);
+    // Keep source stylus, but make the tool type touch
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_FINGER;
+    assertNotBlocked(args);
+
+    // Second pointer (stylus pointer) goes down, from the same device
+    args = generateMotionArgs(1 /*downTime*/, 2 /*eventTime*/, POINTER_1_DOWN, {{1, 2}, {10, 20}},
+                              STYLUS);
+    // Keep source stylus, but make the tool type touch
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    assertNotBlocked(args);
+
+    // Second pointer (stylus pointer) goes down, from the same device
+    args = generateMotionArgs(1 /*downTime*/, 3 /*eventTime*/, MOVE, {{2, 3}, {11, 21}}, STYLUS);
+    // Keep source stylus, but make the tool type touch
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_FINGER;
+    assertNotBlocked(args);
+}
+
+/**
+ * When there are two touch devices, stylus down should cancel all current touch streams.
+ */
+TEST_F(PreferStylusOverTouchTest, TouchFromTwoDevicesAndStylus) {
+    NotifyMotionArgs touch1Down =
+            generateMotionArgs(1 /*downTime*/, 1 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertNotBlocked(touch1Down);
+
+    NotifyMotionArgs touch2Down =
+            generateMotionArgs(2 /*downTime*/, 2 /*eventTime*/, DOWN, {{3, 4}}, TOUCHSCREEN);
+    touch2Down.deviceId = SECOND_TOUCH_DEVICE_ID;
+    assertNotBlocked(touch2Down);
+
+    NotifyMotionArgs stylusDown =
+            generateMotionArgs(3 /*downTime*/, 3 /*eventTime*/, DOWN, {{10, 30}}, STYLUS);
+    NotifyMotionArgs cancelArgs1 = touch1Down;
+    cancelArgs1.action = CANCEL;
+    cancelArgs1.flags |= AMOTION_EVENT_FLAG_CANCELED;
+    NotifyMotionArgs cancelArgs2 = touch2Down;
+    cancelArgs2.action = CANCEL;
+    cancelArgs2.flags |= AMOTION_EVENT_FLAG_CANCELED;
+    assertResponse(stylusDown, {cancelArgs1, cancelArgs2, stylusDown});
+}
+
+/**
+ * Touch should be canceled when stylus goes down. After the stylus lifts up, the touch from that
+ * device should continue to be canceled.
+ * If one of the devices is already canceled, it should remain canceled, but new touches from a
+ * different device should go through.
+ */
+TEST_F(PreferStylusOverTouchTest, AllTouchMustLiftAfterCanceledByStylus) {
+    // First device touches down
+    NotifyMotionArgs touch1Down =
+            generateMotionArgs(1 /*downTime*/, 1 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertNotBlocked(touch1Down);
+
+    // Stylus goes down - touch should be canceled
+    NotifyMotionArgs stylusDown =
+            generateMotionArgs(2 /*downTime*/, 2 /*eventTime*/, DOWN, {{10, 30}}, STYLUS);
+    NotifyMotionArgs cancelArgs1 = touch1Down;
+    cancelArgs1.action = CANCEL;
+    cancelArgs1.flags |= AMOTION_EVENT_FLAG_CANCELED;
+    assertResponse(stylusDown, {cancelArgs1, stylusDown});
+
+    // Stylus goes up
+    NotifyMotionArgs stylusUp =
+            generateMotionArgs(2 /*downTime*/, 3 /*eventTime*/, UP, {{10, 30}}, STYLUS);
+    assertNotBlocked(stylusUp);
+
+    // Touch from the first device remains blocked
+    NotifyMotionArgs touch1Move =
+            generateMotionArgs(1 /*downTime*/, 4 /*eventTime*/, MOVE, {{2, 3}}, TOUCHSCREEN);
+    assertDropped(touch1Move);
+
+    // Second touch goes down. It should not be blocked because stylus has already lifted.
+    NotifyMotionArgs touch2Down =
+            generateMotionArgs(5 /*downTime*/, 5 /*eventTime*/, DOWN, {{31, 32}}, TOUCHSCREEN);
+    touch2Down.deviceId = SECOND_TOUCH_DEVICE_ID;
+    assertNotBlocked(touch2Down);
+
+    // First device is lifted up. It's already been canceled, so the UP event should be dropped.
+    NotifyMotionArgs touch1Up =
+            generateMotionArgs(1 /*downTime*/, 6 /*eventTime*/, UP, {{2, 3}}, TOUCHSCREEN);
+    assertDropped(touch1Up);
+
+    // Touch from second device touch should continue to work
+    NotifyMotionArgs touch2Move =
+            generateMotionArgs(5 /*downTime*/, 7 /*eventTime*/, MOVE, {{32, 33}}, TOUCHSCREEN);
+    touch2Move.deviceId = SECOND_TOUCH_DEVICE_ID;
+    assertNotBlocked(touch2Move);
+
+    // Second touch lifts up
+    NotifyMotionArgs touch2Up =
+            generateMotionArgs(5 /*downTime*/, 8 /*eventTime*/, UP, {{32, 33}}, TOUCHSCREEN);
+    touch2Up.deviceId = SECOND_TOUCH_DEVICE_ID;
+    assertNotBlocked(touch2Up);
+
+    // Now that all touch has been lifted, new touch from either first or second device should work
+    NotifyMotionArgs touch3Down =
+            generateMotionArgs(9 /*downTime*/, 9 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertNotBlocked(touch3Down);
+
+    NotifyMotionArgs touch4Down =
+            generateMotionArgs(10 /*downTime*/, 10 /*eventTime*/, DOWN, {{100, 200}}, TOUCHSCREEN);
+    touch4Down.deviceId = SECOND_TOUCH_DEVICE_ID;
+    assertNotBlocked(touch4Down);
+}
+
+/**
+ * When we don't know that a specific device does both stylus and touch, and we only see touch
+ * pointers from it, we should treat it as a touch device. That means, the device events should be
+ * canceled when stylus from another device goes down. When we detect simultaneous touch and stylus
+ * from this device though, we should just pass this device through without canceling anything.
+ *
+ * In this test:
+ * 1. Start by touching down with device 1
+ * 2. Device 2 has stylus going down
+ * 3. Device 1 should be canceled.
+ * 4. When we add stylus pointers to the device 1, they should continue to be canceled.
+ * 5. Device 1 lifts up.
+ * 6. Subsequent events from device 1 should not be canceled even if stylus is down.
+ * 7. If a reset happens, and such device is no longer there, then we should
+ * Therefore, the device 1 is "ignored" and does not participate into "prefer stylus over touch"
+ * behaviour.
+ */
+TEST_F(PreferStylusOverTouchTest, MixedStylusAndTouchDeviceIsCanceledAtFirst) {
+    // Touch from device 1 goes down
+    NotifyMotionArgs touchDown =
+            generateMotionArgs(1 /*downTime*/, 1 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    touchDown.source = STYLUS;
+    assertNotBlocked(touchDown);
+
+    // Stylus from device 2 goes down. Touch should be canceled.
+    NotifyMotionArgs args =
+            generateMotionArgs(2 /*downTime*/, 2 /*eventTime*/, DOWN, {{10, 20}}, STYLUS);
+    NotifyMotionArgs cancelTouchArgs = touchDown;
+    cancelTouchArgs.action = CANCEL;
+    cancelTouchArgs.flags |= AMOTION_EVENT_FLAG_CANCELED;
+    assertResponse(args, {cancelTouchArgs, args});
+
+    // Introduce a stylus pointer into the device 1 stream. It should be ignored.
+    args = generateMotionArgs(1 /*downTime*/, 3 /*eventTime*/, POINTER_1_DOWN, {{1, 2}, {3, 4}},
+                              TOUCHSCREEN);
+    args.pointerProperties[1].toolType = AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    args.source = STYLUS;
+    assertDropped(args);
+
+    // Lift up touch from the mixed touch/stylus device
+    args = generateMotionArgs(1 /*downTime*/, 4 /*eventTime*/, CANCEL, {{1, 2}, {3, 4}},
+                              TOUCHSCREEN);
+    args.pointerProperties[1].toolType = AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    args.source = STYLUS;
+    assertDropped(args);
+
+    // Stylus from device 2 is still down. Since the device 1 is now identified as a mixed
+    // touch/stylus device, its events should go through, even if they are touch.
+    args = generateMotionArgs(5 /*downTime*/, 5 /*eventTime*/, DOWN, {{21, 22}}, TOUCHSCREEN);
+    touchDown.source = STYLUS;
+    assertResponse(args, {args});
+
+    // Reconfigure such that only the stylus device remains
+    InputDeviceInfo stylusDevice;
+    stylusDevice.initialize(STYLUS_DEVICE_ID, 1 /*generation*/, 1 /*controllerNumber*/,
+                            {} /*identifier*/, "stylus device", false /*external*/,
+                            false /*hasMic*/);
+    notifyInputDevicesChanged({stylusDevice});
+    // The touchscreen device was removed, so we no longer remember anything about it. We should
+    // again start blocking touch events from it.
+    args = generateMotionArgs(6 /*downTime*/, 6 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    args.source = STYLUS;
+    assertDropped(args);
+}
+
+/**
+ * If two styli are active at the same time, touch should be blocked until both of them are lifted.
+ * If one of them lifts, touch should continue to be blocked.
+ */
+TEST_F(PreferStylusOverTouchTest, TouchIsBlockedWhenTwoStyliAreUsed) {
+    NotifyMotionArgs args;
+
+    // First stylus is down
+    assertNotBlocked(generateMotionArgs(0 /*downTime*/, 0 /*eventTime*/, DOWN, {{10, 30}}, STYLUS));
+
+    // Second stylus is down
+    args = generateMotionArgs(1 /*downTime*/, 1 /*eventTime*/, DOWN, {{20, 40}}, STYLUS);
+    args.deviceId = SECOND_STYLUS_DEVICE_ID;
+    assertNotBlocked(args);
+
+    // Touch goes down. It should be ignored.
+    args = generateMotionArgs(2 /*downTime*/, 2 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    // Lift the first stylus
+    args = generateMotionArgs(0 /*downTime*/, 3 /*eventTime*/, UP, {{10, 30}}, STYLUS);
+    assertNotBlocked(args);
+
+    // Touch should continue to be blocked
+    args = generateMotionArgs(2 /*downTime*/, 4 /*eventTime*/, UP, {{1, 2}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    // New touch should be blocked because second stylus is still down
+    args = generateMotionArgs(5 /*downTime*/, 5 /*eventTime*/, DOWN, {{5, 6}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    // Second stylus goes up
+    args = generateMotionArgs(1 /*downTime*/, 6 /*eventTime*/, UP, {{20, 40}}, STYLUS);
+    args.deviceId = SECOND_STYLUS_DEVICE_ID;
+    assertNotBlocked(args);
+
+    // Current touch gesture should continue to be blocked
+    // Touch should continue to be blocked
+    args = generateMotionArgs(5 /*downTime*/, 7 /*eventTime*/, UP, {{5, 6}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    // Now that all styli were lifted, new touch should go through
+    args = generateMotionArgs(8 /*downTime*/, 8 /*eventTime*/, DOWN, {{7, 8}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+}
+
 } // namespace android
diff --git a/services/inputflinger/tests/UnwantedInteractionBlocker_test.cpp b/services/inputflinger/tests/UnwantedInteractionBlocker_test.cpp
index b2f8eb3..e378096 100644
--- a/services/inputflinger/tests/UnwantedInteractionBlocker_test.cpp
+++ b/services/inputflinger/tests/UnwantedInteractionBlocker_test.cpp
@@ -519,6 +519,34 @@
             &(args = generateMotionArgs(0 /*downTime*/, 4 /*eventTime*/, MOVE, {{7, 8, 9}})));
 }
 
+/**
+ * Send a touch event, and then a stylus event. Make sure that both work.
+ */
+TEST_F(UnwantedInteractionBlockerTest, StylusAfterTouchWorks) {
+    NotifyMotionArgs args;
+    mBlocker->notifyInputDevicesChanged({generateTestDeviceInfo()});
+    args = generateMotionArgs(0 /*downTime*/, 0 /*eventTime*/, DOWN, {{1, 2, 3}});
+    mBlocker->notifyMotion(&args);
+    args = generateMotionArgs(0 /*downTime*/, 1 /*eventTime*/, MOVE, {{4, 5, 6}});
+    mBlocker->notifyMotion(&args);
+    args = generateMotionArgs(0 /*downTime*/, 2 /*eventTime*/, UP, {{4, 5, 6}});
+    mBlocker->notifyMotion(&args);
+
+    // Now touch down stylus
+    args = generateMotionArgs(3 /*downTime*/, 3 /*eventTime*/, DOWN, {{10, 20, 30}});
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    args.source |= AINPUT_SOURCE_STYLUS;
+    mBlocker->notifyMotion(&args);
+    args = generateMotionArgs(3 /*downTime*/, 4 /*eventTime*/, MOVE, {{40, 50, 60}});
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    args.source |= AINPUT_SOURCE_STYLUS;
+    mBlocker->notifyMotion(&args);
+    args = generateMotionArgs(3 /*downTime*/, 5 /*eventTime*/, UP, {{40, 50, 60}});
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    args.source |= AINPUT_SOURCE_STYLUS;
+    mBlocker->notifyMotion(&args);
+}
+
 using UnwantedInteractionBlockerTestDeathTest = UnwantedInteractionBlockerTest;
 
 /**