static int ssip_pn_xmit()

in clients/ssi_protocol.c [971:1039]

• 55 lines of code
• 11 McCabe index (conditional complexity)

static int ssip_pn_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct hsi_client *cl = to_hsi_client(dev->dev.parent);
	struct ssi_protocol *ssi = hsi_client_drvdata(cl);
	struct hsi_msg *msg;

	if ((skb->protocol != htons(ETH_P_PHONET)) ||
					(skb->len < SSIP_MIN_PN_HDR))
		goto drop;
	/* Pad to 32-bits - FIXME: Revisit*/
	if ((skb->len & 3) && skb_pad(skb, 4 - (skb->len & 3)))
		goto inc_dropped;

	/*
	 * Modem sends Phonet messages over SSI with its own endianness.
	 * Assume that modem has the same endianness as we do.
	 */
	if (skb_cow_head(skb, 0))
		goto drop;

	/* length field is exchanged in network byte order */
	((u16 *)skb->data)[2] = htons(((u16 *)skb->data)[2]);

	msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
	if (!msg) {
		dev_dbg(&cl->device, "Dropping tx data: No memory\n");
		goto drop;
	}
	msg->complete = ssip_tx_data_complete;

	spin_lock_bh(&ssi->lock);
	if (unlikely(ssi->main_state != ACTIVE)) {
		spin_unlock_bh(&ssi->lock);
		dev_dbg(&cl->device, "Dropping tx data: CMT is OFFLINE\n");
		goto drop2;
	}
	list_add_tail(&msg->link, &ssi->txqueue);
	ssi->txqueue_len++;
	if (dev->tx_queue_len < ssi->txqueue_len) {
		dev_info(&cl->device, "TX queue full %d\n", ssi->txqueue_len);
		netif_stop_queue(dev);
	}
	if (ssi->send_state == SEND_IDLE) {
		ssip_set_txstate(ssi, WAIT4READY);
		spin_unlock_bh(&ssi->lock);
		dev_dbg(&cl->device, "Start TX qlen %d\n", ssi->txqueue_len);
		hsi_start_tx(cl);
	} else if (ssi->send_state == SEND_READY) {
		/* Needed for cmt-speech workaround */
		dev_dbg(&cl->device, "Start TX on SEND READY qlen %d\n",
							ssi->txqueue_len);
		spin_unlock_bh(&ssi->lock);
		schedule_work(&ssi->work);
	} else {
		spin_unlock_bh(&ssi->lock);
	}
	dev->stats.tx_packets++;
	dev->stats.tx_bytes += skb->len;

	return 0;
drop2:
	hsi_free_msg(msg);
drop:
	dev_kfree_skb(skb);
inc_dropped:
	dev->stats.tx_dropped++;

	return 0;
}