diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 1df86a7..eee19c9 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -56,7 +56,6 @@ struct mt_slot {
 	__s32 x, y, p, w, h;
 	__s32 contactid;	/* the device ContactID assigned to this slot */
 	bool touch_state;	/* is the touch valid? */
-	bool seen_in_this_frame;/* has this slot been updated */
 };
 
 struct mt_class {
@@ -94,7 +93,6 @@ struct mt_device {
 				* > 1 means hybrid (multitouch) protocol */
 	bool serial_maybe;	/* need to check for serial protocol */
 	bool curvalid;		/* is the current contact valid? */
-	struct mt_slot *slots;
 	unsigned mt_flags;	/* flags to pass to input-mt */
 };
 
@@ -136,25 +134,6 @@ static int cypress_compute_slot(struct mt_device *td)
 		return -1;
 }
 
-static int find_slot_from_contactid(struct mt_device *td)
-{
-	int i;
-	for (i = 0; i < td->maxcontacts; ++i) {
-		if (td->slots[i].contactid == td->curdata.contactid &&
-			td->slots[i].touch_state)
-			return i;
-	}
-	for (i = 0; i < td->maxcontacts; ++i) {
-		if (!td->slots[i].seen_in_this_frame &&
-			!td->slots[i].touch_state)
-			return i;
-	}
-	/* should not occurs. If this happens that means
-	 * that the device sent more touches that it says
-	 * in the report descriptor. It is ignored then. */
-	return -1;
-}
-
 static struct mt_class mt_classes[] = {
 	{ .name = MT_CLS_DEFAULT,
 		.quirks = MT_QUIRK_NOT_SEEN_MEANS_UP },
@@ -448,7 +427,7 @@ static int mt_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 	return -1;
 }
 
-static int mt_compute_slot(struct mt_device *td)
+static int mt_compute_slot(struct mt_device *td, struct input_dev *input)
 {
 	__s32 quirks = td->mtclass.quirks;
 
@@ -464,42 +443,23 @@ static int mt_compute_slot(struct mt_device *td)
 	if (quirks & MT_QUIRK_SLOT_IS_CONTACTID_MINUS_ONE)
 		return td->curdata.contactid - 1;
 
-	return find_slot_from_contactid(td);
+	return input_mt_get_slot_by_key(input, td->curdata.contactid);
 }
 
 /*
  * this function is called when a whole contact has been processed,
  * so that it can assign it to a slot and store the data there
  */
-static void mt_complete_slot(struct mt_device *td)
+static void mt_complete_slot(struct mt_device *td, struct input_dev *input)
 {
-	td->curdata.seen_in_this_frame = true;
 	if (td->curvalid) {
-		int slotnum = mt_compute_slot(td);
-
-		if (slotnum >= 0 && slotnum < td->maxcontacts)
-			td->slots[slotnum] = td->curdata;
-	}
-	td->num_received++;
-}
-
-
-/*
- * this function is called when a whole packet has been received and processed,
- * so that it can decide what to send to the input layer.
- */
-static void mt_emit_event(struct mt_device *td, struct input_dev *input)
-{
-	int i;
+		int slotnum = mt_compute_slot(td, input);
+		struct mt_slot *s = &td->curdata;
 
-	for (i = 0; i < td->maxcontacts; ++i) {
-		struct mt_slot *s = &(td->slots[i]);
-		if ((td->mtclass.quirks & MT_QUIRK_NOT_SEEN_MEANS_UP) &&
-			!s->seen_in_this_frame) {
-			s->touch_state = false;
-		}
+		if (slotnum < 0 || slotnum >= td->maxcontacts)
+			return;
 
-		input_mt_slot(input, i);
+		input_mt_slot(input, slotnum);
 		input_mt_report_slot_state(input, MT_TOOL_FINGER,
 			s->touch_state);
 		if (s->touch_state) {
@@ -516,24 +476,29 @@ static void mt_emit_event(struct mt_device *td, struct input_dev *input)
 			input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
 			input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, minor);
 		}
-		s->seen_in_this_frame = false;
-
 	}
 
+	td->num_received++;
+}
+
+/*
+ * this function is called when a whole packet has been received and processed,
+ * so that it can decide what to send to the input layer.
+ */
+static void mt_sync_frame(struct mt_device *td, struct input_dev *input)
+{
 	input_mt_sync_frame(input);
 	input_sync(input);
 	td->num_received = 0;
 }
 
-
-
 static int mt_event(struct hid_device *hid, struct hid_field *field,
 				struct hid_usage *usage, __s32 value)
 {
 	struct mt_device *td = hid_get_drvdata(hid);
 	__s32 quirks = td->mtclass.quirks;
 
-	if (hid->claimed & HID_CLAIMED_INPUT && td->slots) {
+	if (hid->claimed & HID_CLAIMED_INPUT) {
 		switch (usage->hid) {
 		case HID_DG_INRANGE:
 			if (quirks & MT_QUIRK_ALWAYS_VALID)
@@ -586,11 +551,11 @@ static int mt_event(struct hid_device *hid, struct hid_field *field,
 		}
 
 		if (usage->hid == td->last_slot_field)
-			mt_complete_slot(td);
+			mt_complete_slot(td, field->hidinput->input);
 
 		if (field->index == td->last_field_index
 			&& td->num_received >= td->num_expected)
-			mt_emit_event(td, field->hidinput->input);
+			mt_sync_frame(td, field->hidinput->input);
 
 	}
 
@@ -690,6 +655,9 @@ static void mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
 	if (cls->is_indirect)
 		td->mt_flags |= INPUT_MT_POINTER;
 
+	if (cls->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
+		td->mt_flags |= INPUT_MT_DROP_UNUSED;
+
 	input_mt_init_slots(input, td->maxcontacts, td->mt_flags);
 
 	td->mt_flags = 0;
@@ -743,15 +711,6 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	if (ret)
 		goto fail;
 
-	td->slots = kzalloc(td->maxcontacts * sizeof(struct mt_slot),
-				GFP_KERNEL);
-	if (!td->slots) {
-		dev_err(&hdev->dev, "cannot allocate multitouch slots\n");
-		hid_hw_stop(hdev);
-		ret = -ENOMEM;
-		goto fail;
-	}
-
 	ret = sysfs_create_group(&hdev->dev.kobj, &mt_attribute_group);
 
 	mt_set_maxcontacts(hdev);
@@ -782,7 +741,6 @@ static void mt_remove(struct hid_device *hdev)
 	struct mt_device *td = hid_get_drvdata(hdev);
 	sysfs_remove_group(&hdev->dev.kobj, &mt_attribute_group);
 	hid_hw_stop(hdev);
-	kfree(td->slots);
 	kfree(td);
 	hid_set_drvdata(hdev, NULL);
 }
