- /* unmap the skb */
- skb = descr->skb;
- pci_unmap_single(card->pdev, descr->buf_addr, skb->len,
- PCI_DMA_TODEVICE);
- dev_kfree_skb_any(skb);
+ /* If TX queue is short, don't even bother with interrupts */
+ if (cnt < card->num_tx_desc/4)
+ return cnt;
+
+ /* Set low-watermark 3/4th's of the way into the queue. */
+ descr = card->tx_chain.tail;
+ cnt = (cnt*3)/4;
+ for (i=0;i<cnt; i++)
+ descr = descr->next;
+
+ /* Set the new watermark, clear the old watermark */
+ spin_lock_irqsave(&card->tx_chain.lock, flags);
+ descr->dmac_cmd_status |= SPIDER_NET_DESCR_TXDESFLG;
+ if (card->low_watermark && card->low_watermark != descr)
+ card->low_watermark->dmac_cmd_status =
+ card->low_watermark->dmac_cmd_status & ~SPIDER_NET_DESCR_TXDESFLG;
+ card->low_watermark = descr;
+ spin_unlock_irqrestore(&card->tx_chain.lock, flags);
+ return cnt;