diff --git a/include/utils/BitSet.h b/include/utils/BitSet.h
index de748b5..600017e 100644
--- a/include/utils/BitSet.h
+++ b/include/utils/BitSet.h
@@ -44,6 +44,9 @@
     // Returns true if the bit set does not contain any marked bits.
     inline bool isEmpty() const { return ! value; }
 
+    // Returns true if the bit set does not contain any unmarked bits.
+    inline bool isFull() const { return value == 0xffffffff; }
+
     // Returns true if the specified bit is marked.
     inline bool hasBit(uint32_t n) const { return value & valueForBit(n); }
 
diff --git a/services/input/InputReader.cpp b/services/input/InputReader.cpp
index 79218a5..6a6e72e 100644
--- a/services/input/InputReader.cpp
+++ b/services/input/InputReader.cpp
@@ -5403,6 +5403,7 @@
     mAccumulator.clearSlots(mSlotCount);
     mAccumulator.clearButtons();
     mButtonState = 0;
+    mPointerIdBits.clear();
 
     if (mUsingSlotsProtocol) {
         // Query the driver for the current slot index and use it as the initial slot
@@ -5627,28 +5628,32 @@
 
         // Assign pointer id using tracking id if available.
         if (havePointerIds) {
-            int32_t id;
-            if (mUsingSlotsProtocol) {
-                id = inIndex;
-            } else if (fields & Accumulator::FIELD_ABS_MT_TRACKING_ID) {
-                id = inSlot.absMTTrackingId;
-            } else {
-                id = -1;
-            }
+            int32_t id = -1;
+            if (fields & Accumulator::FIELD_ABS_MT_TRACKING_ID) {
+                int32_t trackingId = inSlot.absMTTrackingId;
 
-            if (id >= 0 && id <= MAX_POINTER_ID) {
+                for (BitSet32 idBits(mPointerIdBits); !idBits.isEmpty(); ) {
+                    uint32_t n = idBits.firstMarkedBit();
+                    idBits.clearBit(n);
+
+                    if (mPointerTrackingIdMap[n] == trackingId) {
+                        id = n;
+                    }
+                }
+
+                if (id < 0 && !mPointerIdBits.isFull()) {
+                    id = mPointerIdBits.firstUnmarkedBit();
+                    mPointerIdBits.markBit(id);
+                    mPointerTrackingIdMap[id] = trackingId;
+                }
+            }
+            if (id < 0) {
+                havePointerIds = false;
+                mCurrentTouch.idBits.clear();
+            } else {
                 outPointer.id = id;
                 mCurrentTouch.idToIndex[id] = outCount;
                 mCurrentTouch.idBits.markBit(id);
-            } else {
-                if (id >= 0) {
-#if DEBUG_POINTERS
-                    LOGD("Pointers: Ignoring driver provided slot index or tracking id %d because "
-                            "it is larger than the maximum supported pointer id %d",
-                            id, MAX_POINTER_ID);
-#endif
-                }
-                havePointerIds = false;
             }
         }
 
@@ -5660,6 +5665,8 @@
     mButtonState = (mButtonState | mAccumulator.buttonDown) & ~mAccumulator.buttonUp;
     mCurrentTouch.buttonState = mButtonState;
 
+    mPointerIdBits = mCurrentTouch.idBits;
+
     syncTouch(when, havePointerIds);
 
     if (!mUsingSlotsProtocol) {
diff --git a/services/input/InputReader.h b/services/input/InputReader.h
index 288ff4e..181bcf8 100644
--- a/services/input/InputReader.h
+++ b/services/input/InputReader.h
@@ -1401,6 +1401,10 @@
 
     int32_t mButtonState;
 
+    // Specifies the pointer id bits that are in use, and their associated tracking id.
+    BitSet32 mPointerIdBits;
+    int32_t mPointerTrackingIdMap[MAX_POINTER_ID + 1];
+
     void clearState();
 
     void sync(nsecs_t when);
diff --git a/services/input/tests/InputReader_test.cpp b/services/input/tests/InputReader_test.cpp
index d3c5ece..54e5eaa 100644
--- a/services/input/tests/InputReader_test.cpp
+++ b/services/input/tests/InputReader_test.cpp
@@ -3536,7 +3536,7 @@
     ASSERT_NO_FATAL_FAILURE(mFakeDispatcher->assertNotifyMotionWasCalled(&motionArgs));
     ASSERT_EQ(AMOTION_EVENT_ACTION_DOWN, motionArgs.action);
     ASSERT_EQ(size_t(1), motionArgs.pointerCount);
-    ASSERT_EQ(1, motionArgs.pointerProperties[0].id);
+    ASSERT_EQ(0, motionArgs.pointerProperties[0].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
     ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[0],
             toDisplayX(x1), toDisplayY(y1), 1, 0, 0, 0, 0, 0, 0));
@@ -3545,9 +3545,9 @@
     ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_DOWN | (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
             motionArgs.action);
     ASSERT_EQ(size_t(2), motionArgs.pointerCount);
-    ASSERT_EQ(1, motionArgs.pointerProperties[0].id);
+    ASSERT_EQ(0, motionArgs.pointerProperties[0].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
-    ASSERT_EQ(2, motionArgs.pointerProperties[1].id);
+    ASSERT_EQ(1, motionArgs.pointerProperties[1].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[1].toolType);
     ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[0],
             toDisplayX(x1), toDisplayY(y1), 1, 0, 0, 0, 0, 0, 0));
@@ -3567,9 +3567,9 @@
     ASSERT_NO_FATAL_FAILURE(mFakeDispatcher->assertNotifyMotionWasCalled(&motionArgs));
     ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
     ASSERT_EQ(size_t(2), motionArgs.pointerCount);
-    ASSERT_EQ(1, motionArgs.pointerProperties[0].id);
+    ASSERT_EQ(0, motionArgs.pointerProperties[0].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
-    ASSERT_EQ(2, motionArgs.pointerProperties[1].id);
+    ASSERT_EQ(1, motionArgs.pointerProperties[1].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[1].toolType);
     ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[0],
             toDisplayX(x1), toDisplayY(y1), 1, 0, 0, 0, 0, 0, 0));
@@ -3587,9 +3587,9 @@
     ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_UP | (0 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
             motionArgs.action);
     ASSERT_EQ(size_t(2), motionArgs.pointerCount);
-    ASSERT_EQ(1, motionArgs.pointerProperties[0].id);
+    ASSERT_EQ(0, motionArgs.pointerProperties[0].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
-    ASSERT_EQ(2, motionArgs.pointerProperties[1].id);
+    ASSERT_EQ(1, motionArgs.pointerProperties[1].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[1].toolType);
     ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[0],
             toDisplayX(x1), toDisplayY(y1), 1, 0, 0, 0, 0, 0, 0));
@@ -3599,7 +3599,7 @@
     ASSERT_NO_FATAL_FAILURE(mFakeDispatcher->assertNotifyMotionWasCalled(&motionArgs));
     ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
     ASSERT_EQ(size_t(1), motionArgs.pointerCount);
-    ASSERT_EQ(2, motionArgs.pointerProperties[0].id);
+    ASSERT_EQ(1, motionArgs.pointerProperties[0].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
     ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[0],
             toDisplayX(x2), toDisplayY(y2), 1, 0, 0, 0, 0, 0, 0));
@@ -3614,7 +3614,7 @@
     ASSERT_NO_FATAL_FAILURE(mFakeDispatcher->assertNotifyMotionWasCalled(&motionArgs));
     ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
     ASSERT_EQ(size_t(1), motionArgs.pointerCount);
-    ASSERT_EQ(2, motionArgs.pointerProperties[0].id);
+    ASSERT_EQ(1, motionArgs.pointerProperties[0].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
     ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[0],
             toDisplayX(x2), toDisplayY(y2), 1, 0, 0, 0, 0, 0, 0));
@@ -3630,17 +3630,17 @@
     processSync(mapper);
 
     ASSERT_NO_FATAL_FAILURE(mFakeDispatcher->assertNotifyMotionWasCalled(&motionArgs));
-    ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_DOWN | (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+    ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_DOWN | (0 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
             motionArgs.action);
     ASSERT_EQ(size_t(2), motionArgs.pointerCount);
-    ASSERT_EQ(2, motionArgs.pointerProperties[0].id);
+    ASSERT_EQ(0, motionArgs.pointerProperties[0].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
-    ASSERT_EQ(3, motionArgs.pointerProperties[1].id);
+    ASSERT_EQ(1, motionArgs.pointerProperties[1].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[1].toolType);
     ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[0],
-            toDisplayX(x2), toDisplayY(y2), 1, 0, 0, 0, 0, 0, 0));
-    ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[1],
             toDisplayX(x3), toDisplayY(y3), 1, 0, 0, 0, 0, 0, 0));
+    ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[1],
+            toDisplayX(x2), toDisplayY(y2), 1, 0, 0, 0, 0, 0, 0));
 
     // Second finger up.
     x3 += 30; y3 -= 20;
@@ -3650,22 +3650,22 @@
     processSync(mapper);
 
     ASSERT_NO_FATAL_FAILURE(mFakeDispatcher->assertNotifyMotionWasCalled(&motionArgs));
-    ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_UP | (0 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+    ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_UP | (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
             motionArgs.action);
     ASSERT_EQ(size_t(2), motionArgs.pointerCount);
-    ASSERT_EQ(2, motionArgs.pointerProperties[0].id);
+    ASSERT_EQ(0, motionArgs.pointerProperties[0].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
-    ASSERT_EQ(3, motionArgs.pointerProperties[1].id);
+    ASSERT_EQ(1, motionArgs.pointerProperties[1].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[1].toolType);
     ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[0],
-            toDisplayX(x2), toDisplayY(y2), 1, 0, 0, 0, 0, 0, 0));
-    ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[1],
             toDisplayX(x3), toDisplayY(y3), 1, 0, 0, 0, 0, 0, 0));
+    ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[1],
+            toDisplayX(x2), toDisplayY(y2), 1, 0, 0, 0, 0, 0, 0));
 
     ASSERT_NO_FATAL_FAILURE(mFakeDispatcher->assertNotifyMotionWasCalled(&motionArgs));
     ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
     ASSERT_EQ(size_t(1), motionArgs.pointerCount);
-    ASSERT_EQ(3, motionArgs.pointerProperties[0].id);
+    ASSERT_EQ(0, motionArgs.pointerProperties[0].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
     ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[0],
             toDisplayX(x3), toDisplayY(y3), 1, 0, 0, 0, 0, 0, 0));
@@ -3677,7 +3677,7 @@
     ASSERT_NO_FATAL_FAILURE(mFakeDispatcher->assertNotifyMotionWasCalled(&motionArgs));
     ASSERT_EQ(AMOTION_EVENT_ACTION_UP, motionArgs.action);
     ASSERT_EQ(size_t(1), motionArgs.pointerCount);
-    ASSERT_EQ(3, motionArgs.pointerProperties[0].id);
+    ASSERT_EQ(0, motionArgs.pointerProperties[0].id);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
     ASSERT_NO_FATAL_FAILURE(assertPointerCoords(motionArgs.pointerCoords[0],
             toDisplayX(x3), toDisplayY(y3), 1, 0, 0, 0, 0, 0, 0));
@@ -3728,7 +3728,7 @@
 
     FakeInputDispatcher::NotifyMotionArgs args;
     ASSERT_NO_FATAL_FAILURE(mFakeDispatcher->assertNotifyMotionWasCalled(&args));
-    ASSERT_EQ(id, args.pointerProperties[0].id);
+    ASSERT_EQ(0, args.pointerProperties[0].id);
     ASSERT_NO_FATAL_FAILURE(assertPointerCoords(args.pointerCoords[0],
             x, y, pressure, size, touchMajor, touchMinor, toolMajor, toolMinor, orientation));
 }