AcoSail/kernel_optimize_test
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rt2x00: Map extra_tx_headroom to DMA

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If a driver requests additional headroom it should
be mapped to DMA as well because it will be send to
the hardware as well (as form of extra descriptor).

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Ivo van Doorn 2008-08-29 21:04:50 +02:00 committed by John W. Linville
parent 0262ab0df6
commit 3ee54a07d3
1 changed files with 21 additions and 3 deletions
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24
drivers/net/wireless/rt2x00/rt2x00queue.c
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@ -100,8 +100,21 @@ void rt2x00queue_map_txskb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
{
struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
skbdesc->skb_dma = dma_map_single(rt2x00dev->dev, skb->data, skb->len,
DMA_TO_DEVICE);
/*
* If device has requested headroom, we should make sure that
* is also mapped to the DMA so it can be used for transfering
* additional descriptor information to the hardware.
*/
skb_push(skb, rt2x00dev->hw->extra_tx_headroom);
skbdesc->skb_dma =
dma_map_single(rt2x00dev->dev, skb->data, skb->len, DMA_TO_DEVICE);
/*
* Restore data pointer to original location again.
*/
skb_pull(skb, rt2x00dev->hw->extra_tx_headroom);
skbdesc->flags |= SKBDESC_DMA_MAPPED_TX;
}
EXPORT_SYMBOL_GPL(rt2x00queue_map_txskb);
@ -117,7 +130,12 @@ void rt2x00queue_unmap_skb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
}
if (skbdesc->flags & SKBDESC_DMA_MAPPED_TX) {
dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma, skb->len,
/*
* Add headroom to the skb length, it has been removed
* by the driver, but it was actually mapped to DMA.
*/
dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma,
skb->len + rt2x00dev->hw->extra_tx_headroom,
DMA_TO_DEVICE);
skbdesc->flags &= ~SKBDESC_DMA_MAPPED_TX;
}