Re: [PATCH net-next V5 6/9] Altera TSE: Add main and header file for Altera Ethernet Driver

Hi Richard,

On Fri, Mar 14, 2014 at 9:39 AM, Richard Cochran
[off-list ref] wrote:

On Fri, Mar 14, 2014 at 09:04:44AM -0500, Vince Bridgers wrote:

quoted

+static int tse_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+     struct altera_tse_private *priv = netdev_priv(dev);
+     unsigned int txsize = priv->tx_ring_size;
+     unsigned int entry;
+     struct tse_buffer *buffer = NULL;
+     int nfrags = skb_shinfo(skb)->nr_frags;
+     unsigned int nopaged_len = skb_headlen(skb);
+     enum netdev_tx ret = NETDEV_TX_OK;
+     dma_addr_t dma_addr;
+     int txcomplete = 0;
+
+     spin_lock_bh(&priv->tx_lock);
+
+     if (unlikely(tse_tx_avail(priv) < nfrags + 1)) {
+             if (!netif_queue_stopped(dev)) {
+                     netif_stop_queue(dev);
+                     /* This is a hard error, log it. */
+                     netdev_err(priv->dev,
+                                "%s: Tx list full when queue awake\n",
+                                __func__);
+             }
+             ret = NETDEV_TX_BUSY;
+             goto out;
+     }
+
+     /* Map the first skb fragment */
+     entry = priv->tx_prod % txsize;
+     buffer = &priv->tx_ring[entry];
+
+     dma_addr = dma_map_single(priv->device, skb->data, nopaged_len,
+                               DMA_TO_DEVICE);
+     if (dma_mapping_error(priv->device, dma_addr)) {
+             netdev_err(priv->dev, "%s: DMA mapping error\n", __func__);
+             ret = NETDEV_TX_OK;
+             goto out;
+     }
+
+     buffer->skb = skb;
+     buffer->dma_addr = dma_addr;
+     buffer->len = nopaged_len;
+
+     /* Push data out of the cache hierarchy into main memory */
+     dma_sync_single_for_device(priv->device, buffer->dma_addr,
+                                buffer->len, DMA_TO_DEVICE);
+
+     txcomplete = priv->dmaops->tx_buffer(priv, buffer);
+
+     priv->tx_prod++;
+     dev->stats.tx_bytes += skb->len;

This could use a call to skb_tx_timestamp() somewhere around here.

Thank you, I'll add the call

quoted

+
+     if (unlikely(tse_tx_avail(priv) <= TXQUEUESTOP_THRESHHOLD)) {
+             if (netif_msg_hw(priv))
+                     netdev_dbg(priv->dev, "%s: stop transmitted packets\n",
+                                __func__);
+             netif_stop_queue(dev);
+     }
+
+out:
+     spin_unlock_bh(&priv->tx_lock);
+
+     return ret;
+}

Thanks,
Richard

All the best,

Vince