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authorMing Lei <tom.leiming@gmail.com>2010-05-15 18:25:40 +0800
committerJohn W. Linville <linville@tuxdriver.com>2010-06-04 14:55:09 -0400
commitce9426d1908001fb2f7b0152fbe4184bbc0c7b68 (patch)
tree42389f116a18a2ba8c3d7b20f52d591766bb9602 /drivers/net
parent26b36cfefaf2be98b225e3c1a399edb0daf52ddd (diff)
ath9k: fix dma sync in rx path
If buffer is to be accessed by cpu after dma is over, but between dma mapping and dma unmapping, we should use dma_sync_single_for_cpu to sync the buffer between cpu with device. And dma_sync_single_for_device is used to let device gain the buffer again. v2: Felix pointed out dma_sync_single_for_device is needed to return buffer to device if an unsuccessful status bit check is found. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Acked-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/wireless/ath/ath9k/recv.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 1618f8fe195..d373364ef8a 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -700,12 +700,16 @@ static bool ath_edma_get_buffers(struct ath_softc *sc,
bf = SKB_CB_ATHBUF(skb);
BUG_ON(!bf);
- dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
+ dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
common->rx_bufsize, DMA_FROM_DEVICE);
ret = ath9k_hw_process_rxdesc_edma(ah, NULL, skb->data);
- if (ret == -EINPROGRESS)
+ if (ret == -EINPROGRESS) {
+ /*let device gain the buffer again*/
+ dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
+ common->rx_bufsize, DMA_FROM_DEVICE);
return false;
+ }
__skb_unlink(skb, &rx_edma->rx_fifo);
if (ret == -EINVAL) {
@@ -814,7 +818,7 @@ static struct ath_buf *ath_get_next_rx_buf(struct ath_softc *sc,
* 1. accessing the frame
* 2. requeueing the same buffer to h/w
*/
- dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
+ dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
common->rx_bufsize,
DMA_FROM_DEVICE);