bcom_retrieve_buffer
bcom_retrieve_buffer(priv->dmatsk, NULL, NULL);
skb = bcom_retrieve_buffer(s, NULL, (struct bcom_bd **)&bd);
skb = bcom_retrieve_buffer(priv->tx_dmatsk, NULL,
rskb = bcom_retrieve_buffer(priv->rx_dmatsk, &status,
bcom_retrieve_buffer(s->bcom_task, NULL, NULL);