+ new_before_last_rx = nic->rx_to_use->prev->prev;
+ if (new_before_last_rx != old_before_last_rx) {
+ /* Set the el-bit on the buffer that is before the last buffer.
+ * This lets us update the next pointer on the last buffer
+ * without worrying about hardware touching it.
+ * We set the size to 0 to prevent hardware from touching this
+ * buffer.
+ * When the hardware hits the before last buffer with el-bit
+ * and size of 0, it will RNR interrupt, the RUS will go into
+ * the No Resources state. It will not complete nor write to
+ * this buffer. */
+ new_before_last_rfd =
+ (struct rfd *)new_before_last_rx->skb->data;
+ new_before_last_rfd->size = 0;
+ new_before_last_rfd->command |= cpu_to_le16(cb_el);
+ pci_dma_sync_single_for_device(nic->pdev,
+ new_before_last_rx->dma_addr, sizeof(struct rfd),
+ PCI_DMA_TODEVICE);
+
+ /* Now that we have a new stopping point, we can clear the old
+ * stopping point. We must sync twice to get the proper
+ * ordering on the hardware side of things. */
+ old_before_last_rfd->command &= ~cpu_to_le16(cb_el);
+ pci_dma_sync_single_for_device(nic->pdev,
+ old_before_last_rx->dma_addr, sizeof(struct rfd),
+ PCI_DMA_TODEVICE);
+ old_before_last_rfd->size = cpu_to_le16(VLAN_ETH_FRAME_LEN);
+ pci_dma_sync_single_for_device(nic->pdev,
+ old_before_last_rx->dma_addr, sizeof(struct rfd),
+ PCI_DMA_TODEVICE);
+ }
+