Bluetooth: Temporarily stop background scanning on discovery

If the user sends a mgmt start discovery command while the background
scanning is running, we should temporarily stop it. Once the discovery
finishes, we start the background scanning again.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/hci_core.c

@@ -1786,6 +1786,8 @@ void hci_discovery_set_state(struct hci_dev *hdev, int state)
 
 	switch (state) {
 	case DISCOVERY_STOPPED:
+		hci_update_background_scan(hdev);
+
 		if (hdev->discovery.state != DISCOVERY_STARTING)
 			mgmt_discovering(hdev, 0);
 		break;

net/bluetooth/mgmt.c

@@ -3439,12 +3439,12 @@ static int start_discovery(struct sock *sk, struct hci_dev *hdev,
 			goto failed;
 		}
 
-		if (test_bit(HCI_LE_SCAN, &hdev->dev_flags)) {
-			err = cmd_status(sk, hdev->id, MGMT_OP_START_DISCOVERY,
-					 MGMT_STATUS_BUSY);
-			mgmt_pending_remove(cmd);
-			goto failed;
-		}
+		/* If controller is scanning, it means the background scanning
+		 * is running. Thus, we should temporarily stop it in order to
+		 * set the discovery scanning parameters.
+		 */
+		if (test_bit(HCI_LE_SCAN, &hdev->dev_flags))
+			hci_req_add_le_scan_disable(&req);
 
 		memset(&param_cp, 0, sizeof(param_cp));