Bluetooth: Fix link security setting when powering on

If a controller is powered on while the HCI_AUTO_OFF flag is set the
link security setting (HCI_LINK_SECURITY) might not be in sync with the
actual state of the controller (HCI_AUTH). This patch fixes the issue by
checking for inequality between the intended and actual settings and
sends a HCI_Write_Auth_Enable command if necessary.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

net/bluetooth/mgmt.c

@@ -3073,6 +3073,8 @@ int mgmt_powered(struct hci_dev *hdev, u8 powered)
 	mgmt_pending_foreach(MGMT_OP_SET_POWERED, hdev, settings_rsp, &match);
 
 	if (powered) {
+		u8 link_sec;
+
 		if (test_bit(HCI_SSP_ENABLED, &hdev->dev_flags) &&
 		    !lmp_host_ssp_capable(hdev)) {
 			u8 ssp = 1;
@@ -3096,6 +3098,11 @@ int mgmt_powered(struct hci_dev *hdev, u8 powered)
 					     sizeof(cp), &cp);
 		}
 
+		link_sec = test_bit(HCI_LINK_SECURITY, &hdev->dev_flags);
+		if (link_sec != test_bit(HCI_AUTH, &hdev->flags))
+			hci_send_cmd(hdev, HCI_OP_WRITE_AUTH_ENABLE,
+				     sizeof(link_sec), &link_sec);
+
 		if (lmp_bredr_capable(hdev)) {
 			set_bredr_scan(hdev);
 			update_class(hdev);