[PATCH 1/6] HID: wacom: Re-enable touch by default for Cintiq 24HDT / 27QHDT

@@ -3831,7 +3831,7 @@ int wacom_setup_touch_input_capabilities(struct input_dev *input_dev,
 		    wacom_wac->shared->touch->product == 0xF6) {
 			input_dev->evbit[0] |= BIT_MASK(EV_SW);
 			__set_bit(SW_MUTE_DEVICE, input_dev->swbit);
-			wacom_wac->shared->has_mute_touch_switch = true;
+			wacom_wac->has_mute_touch_switch = true;
 		}
 		fallthrough;
 

@@ -2797,6 +2797,7 @@ static int wacom_probe(struct hid_device *hdev,
 				 error);
 	}
 
+	wacom_wac->probe_complete = true;
 	return 0;
 }
 

@@ -2581,6 +2581,12 @@ static void wacom_wac_finger_event(struct hid_device *hdev,
 	unsigned equivalent_usage = wacom_equivalent_usage(usage->hid);
 	struct wacom_features *features = &wacom->wacom_wac.features;
 
+	/* don't process touch events when touch is off */
+	if (wacom_wac->probe_complete &&
+	    !wacom_wac->shared->is_touch_on &&
+	    !wacom_wac->shared->touch_down)
+		return;
+
 	if (wacom_wac->is_invalid_bt_frame)
 		return;
 

@@ -2630,6 +2636,12 @@ static void wacom_wac_finger_pre_report(struct hid_device *hdev,
 	struct hid_data* hid_data = &wacom_wac->hid_data;
 	int i;
 
+	/* don't process touch events when touch is off */
+	if (wacom_wac->probe_complete &&
+	    !wacom_wac->shared->is_touch_on &&
+	    !wacom_wac->shared->touch_down)
+		return;
+
 	wacom_wac->is_invalid_bt_frame = false;
 
 	for (i = 0; i < report->maxfield; i++) {

@@ -337,6 +337,7 @@ struct wacom_wac {
 	int tool[2];
 	int id[2];
 	__u64 serial[2];
+	bool probe_complete;
 	bool reporting_data;
 	struct wacom_features features;
 	struct wacom_shared *shared;

@@ -2287,7 +2287,13 @@ static void wacom_set_shared_values(struct wacom_wac *wacom_wac)
 
 	if (wacom_wac->has_mute_touch_switch) {
 		wacom_wac->shared->has_mute_touch_switch = true;
-		wacom_wac->shared->is_touch_on = true;
+		/* Hardware touch switch may be off. Wait until
+		 * we know the switch state to decide is_touch_on.
+		 * Softkey state should be initialized to "on" to
+		 * match historic default.
+		 */
+		if (wacom_wac->is_soft_touch_switch)
+			wacom_wac->shared->is_touch_on = true;
 	}
 
 	if (wacom_wac->shared->has_mute_touch_switch &&

@@ -1987,14 +1987,17 @@ static void wacom_wac_pad_usage_mapping(struct hid_device *hdev,
 		features->numbered_buttons++;
 		features->device_type |= WACOM_DEVICETYPE_PAD;
 		break;
-	case WACOM_HID_WD_TOUCHONOFF:
 	case WACOM_HID_WD_MUTE_DEVICE:
+		/* softkey touch switch */
+		wacom_wac->is_soft_touch_switch = true;
+		fallthrough;
+	case WACOM_HID_WD_TOUCHONOFF:
 		/*
-		 * This usage, which is used to mute touch events, comes
-		 * from the pad packet, but is reported on the touch
+		 * These two usages, which are used to mute touch events, come
+		 * from the pad packet, but are reported on the touch
 		 * interface. Because the touch interface may not have
 		 * been created yet, we cannot call wacom_map_usage(). In
-		 * order to process this usage when we receive it, we set
+		 * order to process the usages when we receive them, we set
 		 * the usage type and code directly.
 		 */
 		wacom_wac->has_mute_touch_switch = true;

@@ -3832,6 +3835,7 @@ int wacom_setup_touch_input_capabilities(struct input_dev *input_dev,
 			input_dev->evbit[0] |= BIT_MASK(EV_SW);
 			__set_bit(SW_MUTE_DEVICE, input_dev->swbit);
 			wacom_wac->has_mute_touch_switch = true;
+			wacom_wac->is_soft_touch_switch = true;
 		}
 		fallthrough;
 

@@ -352,6 +352,7 @@ struct wacom_wac {
 	int mode_value;
 	struct hid_data hid_data;
 	bool has_mute_touch_switch;
+	bool is_soft_touch_switch;
 	bool has_mode_change;
 	bool is_direct_mode;
 	bool is_invalid_bt_frame;

@@ -2551,6 +2551,9 @@ static void wacom_wac_finger_slot(struct wacom_wac *wacom_wac,
 		int slot;
 
 		slot = input_mt_get_slot_by_key(input, hid_data->id);
+		if (slot < 0)
+			return;
+
 		input_mt_slot(input, slot);
 		input_mt_report_slot_state(input, MT_TOOL_FINGER, prox);
 	}

@@ -824,6 +824,13 @@ static int wacom_intuos_inout(struct wacom_wac *wacom)
 	return 0;
 }
 
+static inline bool touch_is_muted(struct wacom_wac *wacom_wac)
+{
+	return wacom_wac->probe_complete &&
+	       wacom_wac->shared->has_mute_touch_switch &&
+	       !wacom_wac->shared->is_touch_on;
+}
+
 static inline bool report_touch_events(struct wacom_wac *wacom)
 {
 	return (touch_arbitration ? !wacom->shared->stylus_in_proximity : 1);

@@ -1525,11 +1532,8 @@ static int wacom_24hdt_irq(struct wacom_wac *wacom)
 	int byte_per_packet = WACOM_BYTES_PER_24HDT_PACKET;
 	int y_offset = 2;
 
-	if (wacom->shared->has_mute_touch_switch &&
-	    !wacom->shared->is_touch_on) {
-		if (!wacom->shared->touch_down)
-			return 0;
-	}
+	if (touch_is_muted(wacom) && !wacom->shared->touch_down)
+		return 0;
 
 	if (wacom->features.type == WACOM_27QHDT) {
 		current_num_contacts = data[63];

@@ -2536,8 +2540,7 @@ static void wacom_wac_finger_slot(struct wacom_wac *wacom_wac,
 	bool prox = hid_data->tipswitch &&
 		    report_touch_events(wacom_wac);
 
-	if (wacom_wac->shared->has_mute_touch_switch &&
-	    !wacom_wac->shared->is_touch_on) {
+	if (touch_is_muted(wacom_wac)) {
 		if (!wacom_wac->shared->touch_down)
 			return;
 		prox = false;

@@ -2593,10 +2596,7 @@ static void wacom_wac_finger_event(struct hid_device *hdev,
 	unsigned equivalent_usage = wacom_equivalent_usage(usage->hid);
 	struct wacom_features *features = &wacom->wacom_wac.features;
 
-	/* don't process touch events when touch is off */
-	if (wacom_wac->probe_complete &&
-	    !wacom_wac->shared->is_touch_on &&
-	    !wacom_wac->shared->touch_down)
+	if (touch_is_muted(wacom_wac) && !wacom_wac->shared->touch_down)
 		return;
 
 	if (wacom_wac->is_invalid_bt_frame)

@@ -2648,10 +2648,7 @@ static void wacom_wac_finger_pre_report(struct hid_device *hdev,
 	struct hid_data* hid_data = &wacom_wac->hid_data;
 	int i;
 
-	/* don't process touch events when touch is off */
-	if (wacom_wac->probe_complete &&
-	    !wacom_wac->shared->is_touch_on &&
-	    !wacom_wac->shared->touch_down)
+	if (touch_is_muted(wacom_wac) && !wacom_wac->shared->touch_down)
 		return;
 
 	wacom_wac->is_invalid_bt_frame = false;

@@ -2551,8 +2551,17 @@ static void wacom_wac_finger_slot(struct wacom_wac *wacom_wac,
 		int slot;
 
 		slot = input_mt_get_slot_by_key(input, hid_data->id);
-		if (slot < 0)
+		if (slot < 0) {
 			return;
+		} else {
+			struct input_mt_slot *ps = &input->mt->slots[slot];
+			int mt_id = input_mt_get_value(ps, ABS_MT_TRACKING_ID);
+
+			if (!prox && mt_id < 0) {
+				// No data to send for this slot; short-circuit
+				return;
+			}
+		}
 
 		input_mt_slot(input, slot);
 		input_mt_report_slot_state(input, MT_TOOL_FINGER, prox);

@@ -2696,6 +2705,10 @@ static void wacom_wac_finger_report(struct hid_device *hdev,
 	struct input_dev *input = wacom_wac->touch_input;
 	unsigned touch_max = wacom_wac->features.touch_max;
 
+	/* if there was nothing to process, don't send an empty sync */
+	if (wacom_wac->hid_data.num_expected == 0)
+		return;
+
 	/* If more packets of data are expected, give us a chance to
 	 * process them rather than immediately syncing a partial
 	 * update.