[PATCH 7/8] [Blackfin] EMAC driver: fix bug - invalidate data cache of new_skb->data range when cache is WB

[Bryan Wu]

From: Alexey Demin <bf53x@xxxxx>

It prevents overwritting new data from DMA.

Signed-off-by: Alexey Demin <bf53x@xxxxx>
Signed-off-by: Bryan Wu <bryan.wu@xxxxxxxxxx>
---
 drivers/net/bfin_mac.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/drivers/net/bfin_mac.c b/drivers/net/bfin_mac.c
index f2368b7..0a17fb4 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,
-- 
1.5.3.4
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