diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/wireless/b43/dma.c | 37 |
1 files changed, 33 insertions, 4 deletions
diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c index e228c1de6e11..dfa6c72c3bd2 100644 --- a/drivers/net/wireless/b43/dma.c +++ b/drivers/net/wireless/b43/dma.c @@ -555,11 +555,32 @@ address_error: return 1; } +static bool b43_rx_buffer_is_poisoned(struct b43_dmaring *ring, struct sk_buff *skb) +{ + unsigned char *f = skb->data + ring->frameoffset; + + return ((f[0] & f[1] & f[2] & f[3] & f[4] & f[5] & f[6] & f[7]) == 0xFF); +} + +static void b43_poison_rx_buffer(struct b43_dmaring *ring, struct sk_buff *skb) +{ + struct b43_rxhdr_fw4 *rxhdr; + unsigned char *frame; + + /* This poisons the RX buffer to detect DMA failures. */ + + rxhdr = (struct b43_rxhdr_fw4 *)(skb->data); + rxhdr->frame_len = 0; + + B43_WARN_ON(ring->rx_buffersize < ring->frameoffset + sizeof(struct b43_plcp_hdr6) + 2); + frame = skb->data + ring->frameoffset; + memset(frame, 0xFF, sizeof(struct b43_plcp_hdr6) + 2 /* padding */); +} + static int setup_rx_descbuffer(struct b43_dmaring *ring, struct b43_dmadesc_generic *desc, struct b43_dmadesc_meta *meta, gfp_t gfp_flags) { - struct b43_rxhdr_fw4 *rxhdr; dma_addr_t dmaaddr; struct sk_buff *skb; @@ -568,6 +589,7 @@ static int setup_rx_descbuffer(struct b43_dmaring *ring, skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags); if (unlikely(!skb)) return -ENOMEM; + b43_poison_rx_buffer(ring, skb); dmaaddr = map_descbuffer(ring, skb->data, ring->rx_buffersize, 0); if (b43_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) { /* ugh. try to realloc in zone_dma */ @@ -578,6 +600,7 @@ static int setup_rx_descbuffer(struct b43_dmaring *ring, skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags); if (unlikely(!skb)) return -ENOMEM; + b43_poison_rx_buffer(ring, skb); dmaaddr = map_descbuffer(ring, skb->data, ring->rx_buffersize, 0); if (b43_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) { @@ -592,9 +615,6 @@ static int setup_rx_descbuffer(struct b43_dmaring *ring, ring->ops->fill_descriptor(ring, desc, dmaaddr, ring->rx_buffersize, 0, 0, 0); - rxhdr = (struct b43_rxhdr_fw4 *)(skb->data); - rxhdr->frame_len = 0; - return 0; } @@ -1489,6 +1509,15 @@ static void dma_rx(struct b43_dmaring *ring, int *slot) goto drop; } } + if (unlikely(b43_rx_buffer_is_poisoned(ring, skb))) { + /* Something went wrong with the DMA. + * The device did not touch the buffer and did not overwrite the poison. */ + b43dbg(ring->dev->wl, "DMA RX: Dropping poisoned buffer.\n"); + /* recycle the descriptor buffer. */ + sync_descbuffer_for_device(ring, meta->dmaaddr, + ring->rx_buffersize); + goto drop; + } if (unlikely(len > ring->rx_buffersize)) { /* The data did not fit into one descriptor buffer * and is split over multiple buffers. |