diff options
| author | Ivo van Doorn <ivdoorn@gmail.com> | 2008-08-29 21:04:50 +0200 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2008-08-29 16:24:11 -0400 |
| commit | 3ee54a07d34fd9b5c34bb1488113fb32be58e38f (patch) | |
| tree | 85fb594f4024799d4371019be7fd5d0b277c3624 | |
| parent | 0262ab0df64a67d4c0ed7577a29b7d866819cc68 (diff) | |
rt2x00: Map extra_tx_headroom to DMA
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>
| -rw-r--r-- | drivers/net/wireless/rt2x00/rt2x00queue.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c index d10a8012f38..2822684c505 100644 --- a/drivers/net/wireless/rt2x00/rt2x00queue.c +++ b/drivers/net/wireless/rt2x00/rt2x00queue.c @@ -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; } |