Bluetooth: Store max TX power level for connection

This patch adds support to store local maximum TX power level for
connection when reply for HCI_Read_Transmit_Power_Level is received.

Signed-off-by: Andrzej Kaczmarek <andrzej.kaczmarek@tieto.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/hci_core.h

@@ -382,6 +382,7 @@ struct hci_conn {
 	__u16		le_conn_max_interval;
 	__s8		rssi;
 	__s8		tx_power;
+	__s8		max_tx_power;
 	unsigned long	flags;
 
 	unsigned long	conn_info_timestamp;

net/bluetooth/hci_conn.c

@@ -408,6 +408,7 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
 	conn->remote_auth = 0xff;
 	conn->key_type = 0xff;
 	conn->tx_power = HCI_TX_POWER_INVALID;
+	conn->max_tx_power = HCI_TX_POWER_INVALID;
 
 	set_bit(HCI_CONN_POWER_SAVE, &conn->flags);
 	conn->disc_timeout = HCI_DISCONN_TIMEOUT;

net/bluetooth/hci_event.c

@@ -1282,9 +1282,19 @@ static void hci_cc_read_tx_power(struct hci_dev *hdev, struct sk_buff *skb)
 	hci_dev_lock(hdev);
 
 	conn = hci_conn_hash_lookup_handle(hdev, __le16_to_cpu(rp->handle));
-	if (conn && sent->type == 0x00)
+	if (!conn)
-		conn->tx_power = rp->tx_power;
+		goto unlock;
 
+	switch (sent->type) {
+	case 0x00:
+		conn->tx_power = rp->tx_power;
+		break;
+	case 0x01:
+		conn->max_tx_power = rp->tx_power;
+		break;
+	}
+
+unlock:
 	hci_dev_unlock(hdev);
 }