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Subject[PATCH] [144/275] p54pci: update receive dma buffers before and after processing
Date
2.6.35-longterm review patch.  If anyone has any objections, please let me know.

------------------
From: Christian Lamparter <chunkeey@googlemail.com>

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@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
drivers/net/wireless/p54/p54pci.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

Index: linux-2.6.35.y/drivers/net/wireless/p54/p54pci.c
===================================================================
--- linux-2.6.35.y.orig/drivers/net/wireless/p54/p54pci.c 2011-03-29 22:51:09.343484092 -0700
+++ linux-2.6.35.y/drivers/net/wireless/p54/p54pci.c 2011-03-29 23:03:01.264267821 -0700
@@ -199,6 +199,7 @@
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 @@

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);
}


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