Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event

When the BIS source stops, the controller sends an LE BIG Sync Lost
event (subevent 0x1E). Currently, this event is not handled, causing
the BIS stream to remain active in BlueZ and preventing recovery.

Signed-off-by: Yang Li <[e-mail]>
Signed-off-by: Luiz Augusto von Dentz <[e-mail]>

include/net/bluetooth/hci.h

···
 	__le16  bis[];
 } __packed;
 
+#define HCI_EVT_LE_BIG_SYNC_LOST 0x1e
+struct hci_evt_le_big_sync_lost {
+	__u8    handle;
+	__u8    reason;
+} __packed;
+
 #define HCI_EVT_LE_BIG_INFO_ADV_REPORT	0x22
 struct hci_evt_le_big_info_adv_report {
 	__le16  sync_handle;

include/net/bluetooth/hci_core.h

···
 }
 
 static inline struct hci_conn *
-hci_conn_hash_lookup_big_state(struct hci_dev *hdev, __u8 handle,  __u16 state)
+hci_conn_hash_lookup_big_state(struct hci_dev *hdev, __u8 handle, __u16 state,
+			       __u8 role)
 {
 	struct hci_conn_hash *h = &hdev->conn_hash;
 	struct hci_conn  *c;
···
 	rcu_read_lock();
 
 	list_for_each_entry_rcu(c, &h->list, list) {
-		if (c->type != BIS_LINK || c->state != state)
+		if (c->type != BIS_LINK || c->state != state || c->role != role)
 			continue;
 
 		if (handle == c->iso_qos.bcast.big) {

net/bluetooth/hci_conn.c

···
 	struct hci_link *link;
 
 	/* Look for any BIS that is open for rebinding */
-	conn = hci_conn_hash_lookup_big_state(hdev, qos->bcast.big, BT_OPEN);
+	conn = hci_conn_hash_lookup_big_state(hdev, qos->bcast.big, BT_OPEN,
+					      HCI_ROLE_MASTER);
 	if (conn) {
 		memcpy(qos, &conn->iso_qos, sizeof(*qos));
 		conn->state = BT_CONNECTED;

net/bluetooth/hci_event.c

···
 
 	/* Connect all BISes that are bound to the BIG */
 	while ((conn = hci_conn_hash_lookup_big_state(hdev, ev->handle,
-						      BT_BOUND))) {
+						      BT_BOUND,
+						      HCI_ROLE_MASTER))) {
 		if (ev->status) {
 			hci_connect_cfm(conn, ev->status);
 			hci_conn_del(conn);
···
 		}
 
 unlock:
+	hci_dev_unlock(hdev);
+}
+
+static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
+				     struct sk_buff *skb)
+{
+	struct hci_evt_le_big_sync_lost *ev = data;
+	struct hci_conn *bis, *conn;
+
+	bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
+
+	hci_dev_lock(hdev);
+
+	/* Delete the pa sync connection */
+	bis = hci_conn_hash_lookup_pa_sync_big_handle(hdev, ev->handle);
+	if (bis) {
+		conn = hci_conn_hash_lookup_pa_sync_handle(hdev,
+							   bis->sync_handle);
+		if (conn)
+			hci_conn_del(conn);
+	}
+
+	/* Delete each bis connection */
+	while ((bis = hci_conn_hash_lookup_big_state(hdev, ev->handle,
+						     BT_CONNECTED,
+						     HCI_ROLE_SLAVE))) {
+		clear_bit(HCI_CONN_BIG_SYNC, &bis->flags);
+		hci_disconn_cfm(bis, ev->reason);
+		hci_conn_del(bis);
+	}
+
 	hci_dev_unlock(hdev);
 }
 
···
 	HCI_LE_EV_VL(HCI_EVT_LE_BIG_SYNC_ESTABLISHED,
 		     hci_le_big_sync_established_evt,
 		     sizeof(struct hci_evt_le_big_sync_estabilished),
+		     HCI_MAX_EVENT_SIZE),
+	/* [0x1e = HCI_EVT_LE_BIG_SYNC_LOST] */
+	HCI_LE_EV_VL(HCI_EVT_LE_BIG_SYNC_LOST,
+		     hci_le_big_sync_lost_evt,
+		     sizeof(struct hci_evt_le_big_sync_lost),
 		     HCI_MAX_EVENT_SIZE),
 	/* [0x22 = HCI_EVT_LE_BIG_INFO_ADV_REPORT] */
 	HCI_LE_EV_VL(HCI_EVT_LE_BIG_INFO_ADV_REPORT,