Revert "Bluetooth: validate BLE connection interval updates"

This reverts commit c49a8682.

There are devices which require low connection intervals for usable operation
including keyboards and mice. Forcing a static connection interval for
these types of devices has an impact in latency and causes a regression.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

net/bluetooth/hci_event.c

@@ -5660,11 +5660,6 @@ static void hci_le_remote_conn_param_req_evt(struct hci_dev *hdev,
 		return send_conn_param_neg_reply(hdev, handle,
 						 HCI_ERROR_UNKNOWN_CONN_ID);
 
-	if (min < hcon->le_conn_min_interval ||
-	    max > hcon->le_conn_max_interval)
-		return send_conn_param_neg_reply(hdev, handle,
-						 HCI_ERROR_INVALID_LL_PARAMS);
-
 	if (hci_check_conn_params(min, max, latency, timeout))
 		return send_conn_param_neg_reply(hdev, handle,
 						 HCI_ERROR_INVALID_LL_PARAMS);

net/bluetooth/l2cap_core.c

@@ -5305,14 +5305,7 @@ static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
 
 	memset(&rsp, 0, sizeof(rsp));
 
-	if (min < hcon->le_conn_min_interval ||
-	    max > hcon->le_conn_max_interval) {
-		BT_DBG("requested connection interval exceeds current bounds.");
-		err = -EINVAL;
-	} else {
-		err = hci_check_conn_params(min, max, latency, to_multiplier);
-	}
-
+	err = hci_check_conn_params(min, max, latency, to_multiplier);
 	if (err)
 		rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED);
 	else