Bluetooth: AMP: Check that AMP is present and active

Before starting quering remote AMP controllers make sure
that there is local active AMP controller.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

include/net/bluetooth/hci_core.h

@@ -779,6 +779,22 @@ void hci_conn_del_sysfs(struct hci_conn *conn);
 #define lmp_host_le_capable(dev)   !!((dev)->host_features[0] & LMP_HOST_LE)
 #define lmp_host_le_br_capable(dev) !!((dev)->host_features[0] & LMP_HOST_LE_BREDR)
 
+/* returns true if at least one AMP active */
+static inline bool hci_amp_capable(void)
+{
+	struct hci_dev *hdev;
+	bool ret = false;
+
+	read_lock(&hci_dev_list_lock);
+	list_for_each_entry(hdev, &hci_dev_list, list)
+		if (hdev->amp_type == HCI_AMP &&
+		    test_bit(HCI_UP, &hdev->flags))
+			ret = true;
+	read_unlock(&hci_dev_list_lock);
+
+	return ret;
+}
+
 /* ----- HCI protocols ----- */
 #define HCI_PROTO_DEFER             0x01
 

net/bluetooth/l2cap_core.c

@@ -1013,6 +1013,7 @@ static bool __amp_capable(struct l2cap_chan *chan)
 	struct l2cap_conn *conn = chan->conn;
 
 	if (enable_hs &&
+	    hci_amp_capable() &&
 	    chan->chan_policy == BT_CHANNEL_POLICY_AMP_PREFERRED &&
 	    conn->fixed_chan_mask & L2CAP_FC_A2MP)
 		return true;