pcnet32: Fix PCnet32 performance bug on non-coherent architecutres
The PCnet32 driver always passed the the size of the largest possible packet
to the pci_dma_sync_single_for_cpu and pci_dma_sync_single_for_device.
This results in a fairly large "colateral damage" in the caches and makes
the flush operation itself much slower. On a system with a 40MHz CPU this
patch increases network bandwidth by about 12%.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Don Fry <pcnet32@verizon.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/pcnet32.c b/drivers/net/pcnet32.c
index 36f9d98..4d94ba7 100644
--- a/drivers/net/pcnet32.c
+++ b/drivers/net/pcnet32.c
@@ -1234,14 +1234,14 @@
skb_put(skb, pkt_len); /* Make room */
pci_dma_sync_single_for_cpu(lp->pci_dev,
lp->rx_dma_addr[entry],
- PKT_BUF_SZ - 2,
+ pkt_len,
PCI_DMA_FROMDEVICE);
eth_copy_and_sum(skb,
(unsigned char *)(lp->rx_skbuff[entry]->data),
pkt_len, 0);
pci_dma_sync_single_for_device(lp->pci_dev,
lp->rx_dma_addr[entry],
- PKT_BUF_SZ - 2,
+ pkt_len,
PCI_DMA_FROMDEVICE);
}
lp->stats.rx_bytes += skb->len;