[34-longterm 123/247] p54pci: update receive dma buffers before and after processing

[Paul Gortmaker]

From: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    If you see a problem with using this for longterm, please comment.
                   -------------------

commit 0bf719dfdecc5552155cbec78e49fa06e531e35c upstream.

Documentation/DMA-API-HOWTO.txt states:

"DMA transfers need to be synced properly in order for
the cpu and device to see the most uptodate and correct
copy of the DMA buffer."

Signed-off-by: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
 drivers/net/wireless/p54/p54pci.c |   14 +++++++++-----
 1 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/p54/p54pci.c b/drivers/net/wireless/p54/p54pci.c
index e1e3972..5735b6b 100644
--- a/drivers/net/wireless/p54/p54pci.c
+++ b/drivers/net/wireless/p54/p54pci.c
@@ -199,6 +199,7 @@ static void p54p_check_rx_ring(struct ieee80211_hw *dev, u32 *index,
 	while (i != idx) {
 		u16 len;
 		struct sk_buff *skb;
+		dma_addr_t dma_addr;
 		desc = &ring[i];
 		len = le16_to_cpu(desc->len);
 		skb = rx_buf[i];
@@ -216,17 +217,20 @@ static void p54p_check_rx_ring(struct ieee80211_hw *dev, u32 *index,
 
 			len = priv->common.rx_mtu;
 		}
+		dma_addr = le32_to_cpu(desc->host_addr);
+		pci_dma_sync_single_for_cpu(priv->pdev, dma_addr,
+			priv->common.rx_mtu + 32, PCI_DMA_FROMDEVICE);
 		skb_put(skb, len);
 
 		if (p54_rx(dev, skb)) {
-			pci_unmap_single(priv->pdev,
-					 le32_to_cpu(desc->host_addr),
-					 priv->common.rx_mtu + 32,
-					 PCI_DMA_FROMDEVICE);
+			pci_unmap_single(priv->pdev, dma_addr,
+				priv->common.rx_mtu + 32, PCI_DMA_FROMDEVICE);
 			rx_buf[i] = NULL;
-			desc->host_addr = 0;
+			desc->host_addr = cpu_to_le32(0);
 		} else {
 			skb_trim(skb, 0);
+			pci_dma_sync_single_for_device(priv->pdev, dma_addr,
+				priv->common.rx_mtu + 32, PCI_DMA_FROMDEVICE);
 			desc->len = cpu_to_le16(priv->common.rx_mtu + 32);
 		}
 
-- 
1.7.4.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/