Attachment 147898 Details for Bug 219085 – patch to reoder refill operations in sis driver

[patch] patch to reoder refill operations in sis driver

sis900-rhel4.patch (text/plain), 2.45 KB, created by Neil Horman on 2007-02-12 15:15:41 UTC

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Creator: Neil Horman

Created: 2007-02-12 15:15:41 UTC

Size: 2.45 KB

patch

obsolete

>--- linux-2.6.9/drivers/net/sis900.c.orig	2004-10-18 17:53:51.000000000 -0400
>+++ linux-2.6.9/drivers/net/sis900.c	2007-02-12 10:04:40.000000000 -0500
>@@ -1652,6 +1652,24 @@ static int sis900_rx(struct net_device *
> 		} else {
> 			struct sk_buff * skb;
> 
>+			pci_unmap_single(sis_priv->pci_dev,
>+				sis_priv->rx_ring[entry].bufptr, RX_BUF_SIZE,
>+				PCI_DMA_FROMDEVICE);
>+
>+			/* refill the Rx buffer, what if there is not enought
>+			 * memory for new socket buffer ?? */
>+			if ((skb = dev_alloc_skb(RX_BUF_SIZE)) == NULL) {
>+				/*
>+				 * Not enough memory to refill the buffer
>+				 * so we need to recycle the old one so
>+				 * as to avoid creating a memory hole
>+				 * in the rx ring
>+				 */
>+				skb = sis_priv->rx_skbuff[entry];
>+				sis_priv->stats.rx_dropped++;
>+				goto refill_rx_ring;
>+			}	
>+
> 			/* This situation should never happen, but due to
> 			   some unknow bugs, it is possible that
> 			   we are working on NULL sk_buff :-( */
>@@ -1662,9 +1680,6 @@ static int sis900_rx(struct net_device *
> 				break;
> 			}
> 
>-			pci_unmap_single(sis_priv->pci_dev, 
>-				sis_priv->rx_ring[entry].bufptr, RX_BUF_SIZE, 
>-				PCI_DMA_FROMDEVICE);
> 			/* give the socket buffer to upper layers */
> 			skb = sis_priv->rx_skbuff[entry];
> 			skb_put(skb, rx_size);
>@@ -1677,31 +1692,15 @@ static int sis900_rx(struct net_device *
> 			net_dev->last_rx = jiffies;
> 			sis_priv->stats.rx_bytes += rx_size;
> 			sis_priv->stats.rx_packets++;
>+			sis_priv->dirty_rx++;
> 
>-			/* refill the Rx buffer, what if there is not enought memory for
>-			   new socket buffer ?? */
>-			if ((skb = dev_alloc_skb(RX_BUF_SIZE)) == NULL) {
>-				/* not enough memory for skbuff, this makes a "hole"
>-				   on the buffer ring, it is not clear how the
>-				   hardware will react to this kind of degenerated
>-				   buffer */
>-				printk(KERN_INFO "%s: Memory squeeze,"
>-				       "deferring packet.\n",
>-				       net_dev->name);
>-				sis_priv->rx_skbuff[entry] = NULL;
>-				/* reset buffer descriptor state */
>-				sis_priv->rx_ring[entry].cmdsts = 0;
>-				sis_priv->rx_ring[entry].bufptr = 0;
>-				sis_priv->stats.rx_dropped++;
>-				break;
>-			}
>+refill_rx_ring:
> 			skb->dev = net_dev;
> 			sis_priv->rx_skbuff[entry] = skb;
> 			sis_priv->rx_ring[entry].cmdsts = RX_BUF_SIZE;
>                 	sis_priv->rx_ring[entry].bufptr = 
> 				pci_map_single(sis_priv->pci_dev, skb->tail, 
> 					RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
>-			sis_priv->dirty_rx++;
> 		}
> 		sis_priv->cur_rx++;
> 		entry = sis_priv->cur_rx % NUM_RX_DESC;

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Attachments on bug 219085: 147898