A netdev xmit function should return NETDEV_TX_OK or NETDEV_TX_BUSY. Signed-off-by: Martin Kaiser <martin@kaiser.cx> Link: https://lore.kernel.org/r/20210122165749.29467-1-martin@kaiser.cx Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>