EMAC driver: fix bug - invalidate data cache of new_skb->data range when cache is WB

It prevents overwritting new data from DMA.

Signed-off-by: Alexey Demin <bf53x@ya.ru>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/net/bfin_mac.c b/drivers/net/bfin_mac.c
index f2368b71a720..0a17fb48c55c 100644
--- a/drivers/net/bfin_mac.c
+++ b/drivers/net/bfin_mac.c
@@ -651,6 +651,12 @@ static void bf537mac_rx(struct net_device *dev)
         current_rx_ptr->skb = new_skb;
         current_rx_ptr->desc_a.start_addr = (unsigned long)new_skb->data - 2;
 
+        /* Invidate the data cache of skb->data range when it is write back
+         * cache. It will prevent overwritting the new data from DMA
+         */
+        blackfin_dcache_invalidate_range((unsigned long)new_skb->head,
+                                         (unsigned long)new_skb->end);
+
         len = (unsigned short)((current_rx_ptr->status.status_word) & RX_FRLEN);
         skb_put(skb, len);
         blackfin_dcache_invalidate_range((unsigned long)skb->head,