===== drivers/net/sis900.c 1.56 vs edited =====
--- 1.56/drivers/net/sis900.c	2004-08-25 09:15:20 +02:00
+++ edited/drivers/net/sis900.c	2005-01-19 21:48:27 +01:00
@@ -1650,7 +1650,7 @@
 			/* reset buffer descriptor state */
 			sis_priv->rx_ring[entry].cmdsts = RX_BUF_SIZE;
 		} else {
-			struct sk_buff * skb;
+			struct sk_buff * skb, *new_skb;
 
 			/* This situation should never happen, but due to
 			   some unknow bugs, it is possible that
@@ -1662,11 +1662,30 @@
 				break;
 			}
 
+			skb = sis_priv->rx_skbuff[entry];
+
+			if ((new_skb = dev_alloc_skb(RX_BUF_SIZE)) == NULL) {
+				printk(KERN_INFO "%s: memory shortage, rx packet dropped\n",
+					net_dev->name);
+
+				sis_priv->rx_ring[entry].cmdsts = RX_BUF_SIZE;
+				sis_priv->stats.rx_dropped++;
+				sis_priv->dirty_rx++; /* dirty no longer needed? */
+				break; /* next */
+			}
+
 			pci_unmap_single(sis_priv->pci_dev, 
 				sis_priv->rx_ring[entry].bufptr, RX_BUF_SIZE, 
 				PCI_DMA_FROMDEVICE);
+
+			new_skb->dev = net_dev;
+			sis_priv->rx_skbuff[entry] = new_skb;
+			sis_priv->rx_ring[entry].cmdsts = RX_BUF_SIZE;
+                	sis_priv->rx_ring[entry].bufptr = 
+				pci_map_single(sis_priv->pci_dev, new_skb->tail, 
+					RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
+
 			/* give the socket buffer to upper layers */
-			skb = sis_priv->rx_skbuff[entry];
 			skb_put(skb, rx_size);
 			skb->protocol = eth_type_trans(skb, net_dev);
 			netif_rx(skb);
@@ -1678,29 +1697,6 @@
 			sis_priv->stats.rx_bytes += rx_size;
 			sis_priv->stats.rx_packets++;
 
-			/* 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;
-			}
-			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++;
@@ -1708,6 +1704,7 @@
 		rx_status = sis_priv->rx_ring[entry].cmdsts;
 	} // while
 
+#if 0 /* no need to refill skbs are added to the rx ring as packets are received */
 	/* refill the Rx buffer, what if the rate of refilling is slower than 
 	   consuming ?? */
 	for (;sis_priv->cur_rx - sis_priv->dirty_rx > 0; sis_priv->dirty_rx++) {
@@ -1735,6 +1732,7 @@
 					RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
 		}
 	}
+#endif
 	/* re-enable the potentially idle receive state matchine */
 	outl(RxENA | inl(ioaddr + cr), ioaddr + cr );