[PATCH 3.12 31/78] qlge: Fix receive packets drop.

[Jiri Slaby]

From: Manish Chopra <manish.chopra@xxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

[ Upstream commit 2c9a266afefe137bff06bbe0fc48b4d3b3cb348c ]

When running small packets [length < 256 bytes] traffic, packets were
being dropped due to invalid data in those packets which were
delivered by the driver upto the stack. Using pci_dma_sync_single_for_cpu
ensures copying latest and updated data into skb from the receive buffer.

Signed-off-by: Sony Chacko <sony.chacko@xxxxxxxxxx>
Signed-off-by: Manish Chopra <manish.chopra@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 drivers/net/ethernet/qlogic/qlge/qlge_main.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/net/ethernet/qlogic/qlge/qlge_main.c b/drivers/net/ethernet/qlogic/qlge/qlge_main.c
index 2553cf4503b9..151478a59e30 100644
--- a/drivers/net/ethernet/qlogic/qlge/qlge_main.c
+++ b/drivers/net/ethernet/qlogic/qlge/qlge_main.c
@@ -1620,7 +1620,18 @@ static void ql_process_mac_rx_skb(struct ql_adapter *qdev,
 		return;
 	}
 	skb_reserve(new_skb, NET_IP_ALIGN);
+
+	pci_dma_sync_single_for_cpu(qdev->pdev,
+				    dma_unmap_addr(sbq_desc, mapaddr),
+				    dma_unmap_len(sbq_desc, maplen),
+				    PCI_DMA_FROMDEVICE);
+
 	memcpy(skb_put(new_skb, length), skb->data, length);
+
+	pci_dma_sync_single_for_device(qdev->pdev,
+				       dma_unmap_addr(sbq_desc, mapaddr),
+				       dma_unmap_len(sbq_desc, maplen),
+				       PCI_DMA_FROMDEVICE);
 	skb = new_skb;
 
 	/* Frame error, so drop the packet. */
-- 
2.8.1