fm10k_fifo_head_len
u16 len = fm10k_fifo_head_len(fifo);
while (fm10k_fifo_head_len(&mbx->tx) && mbx->pulled) {
for (len = fm10k_fifo_head_len(&mbx->tx);
len = fm10k_fifo_head_len(&mbx->tx)) {
for (len = fm10k_fifo_head_len(fifo);
len = fm10k_fifo_head_len(fifo)) {
u16 msg_size = fm10k_fifo_head_len(&mbx->rx);