[PATCH] hamachi PCI DMA fix from 2.4

Maintainer fix that went into 2.4 last August with the comments
"Get hamachi net driver RX working again.
 Apparently the PCI DMA conversion still has a bug or two left in it..."

drivers/net/hamachi.c

@@ -207,8 +207,10 @@ KERN_INFO "   Further modifications by Keith Underwood <keithu@parl.clemson.edu>
 /* Condensed bus+endian portability operations. */
 #if ADDRLEN == 64
 #define cpu_to_leXX(addr)	cpu_to_le64(addr)
+#define desc_to_virt(addr) bus_to_virt(le64_to_cpu(addr))
 #else 
 #define cpu_to_leXX(addr)	cpu_to_le32(addr)
+#define desc_to_virt(addr) bus_to_virt(le32_to_cpu(addr))
 #endif   
 
 
@@ -1498,7 +1500,7 @@ static int hamachi_rx(struct net_device *dev)
 			break;
 		pci_dma_sync_single(hmp->pci_dev, desc->addr, hmp->rx_buf_sz, 
 			PCI_DMA_FROMDEVICE);
-		buf_addr = (u8 *)hmp->rx_ring + entry*sizeof(*desc);
+		buf_addr = desc_to_virt(desc->addr);
 		frame_status = le32_to_cpu(get_unaligned((s32*)&(buf_addr[data_size - 12])));
 		if (hamachi_debug > 4)
 			printk(KERN_DEBUG "  hamachi_rx() status was %8.8x.\n",