From: Ming Lei Date: Sat, 15 May 2010 10:25:40 +0000 (+0800) Subject: ath9k: fix dma sync in rx path X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ce9426d1908001fb2f7b0152fbe4184bbc0c7b68;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git 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 Acked-by: Felix Fietkau Signed-off-by: John W. Linville --- diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c index 1618f8fe195d..d373364ef8a9 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);