package/mac80211/patches/511-b43-refresh-rx-poison-on-buffer-recycling.patch

   1 The RX buffer poison needs to be refreshed, if we recycle an RX buffer,
   2 because it might be (partially) overwritten by some DMA operations.
   3
   4 Cc: stable@kernel.org
   5 Cc: Francesco Gringoli <francesco.gringoli@ing.unibs.it>
   6 Signed-off-by: Michael Buesch <mb@bu3sch.de>
   7
   8 ---
   9
  10 --- a/drivers/net/wireless/b43/dma.c
  11 +++ b/drivers/net/wireless/b43/dma.c
  12 @@ -1503,20 +1503,16 @@ static void dma_rx(struct b43_dmaring *r
  13                         len = le16_to_cpu(rxhdr->frame_len);
  14                 } while (len == 0 && i++ < 5);
  15                 if (unlikely(len == 0)) {
  16 -                       /* recycle the descriptor buffer. */
  17 -                       sync_descbuffer_for_device(ring, meta->dmaaddr,
  18 -                                                  ring->rx_buffersize);
  19 -                       goto drop;
  20 +                       dmaaddr = meta->dmaaddr;
  21 +                       goto drop_recycle_buffer;
  22                 }
  23         }
  24         if (unlikely(b43_rx_buffer_is_poisoned(ring, skb))) {
  25                 /* Something went wrong with the DMA.
  26                  * The device did not touch the buffer and did not overwrite the poison. */
  27                 b43dbg(ring->dev->wl, "DMA RX: Dropping poisoned buffer.\n");
  28 -               /* recycle the descriptor buffer. */
  29 -               sync_descbuffer_for_device(ring, meta->dmaaddr,
  30 -                                          ring->rx_buffersize);
  31 -               goto drop;
  32 +               dmaaddr = meta->dmaaddr;
  33 +               goto drop_recycle_buffer;
  34         }
  35         if (unlikely(len > ring->rx_buffersize)) {
  36                 /* The data did not fit into one descriptor buffer
  37 @@ -1530,6 +1526,7 @@ static void dma_rx(struct b43_dmaring *r
  38                 while (1) {
  39                         desc = ops->idx2desc(ring, *slot, &meta);
  40                         /* recycle the descriptor buffer. */
  41 +                       b43_poison_rx_buffer(ring, meta->skb);
  42                         sync_descbuffer_for_device(ring, meta->dmaaddr,
  43                                                    ring->rx_buffersize);
  44                         *slot = next_slot(ring, *slot);
  45 @@ -1548,8 +1545,7 @@ static void dma_rx(struct b43_dmaring *r
  46         err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC);
  47         if (unlikely(err)) {
  48                 b43dbg(ring->dev->wl, "DMA RX: setup_rx_descbuffer() failed\n");
  49 -               sync_descbuffer_for_device(ring, dmaaddr, ring->rx_buffersize);
  50 -               goto drop;
  51 +               goto drop_recycle_buffer;
  52         }
  53
  54         unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
  55 @@ -1559,6 +1555,11 @@ static void dma_rx(struct b43_dmaring *r
  56         b43_rx(ring->dev, skb, rxhdr);
  57  drop:
  58         return;
  59 +
  60 +drop_recycle_buffer:
  61 +       /* Poison and recycle the RX buffer. */
  62 +       b43_poison_rx_buffer(ring, skb);
  63 +       sync_descbuffer_for_device(ring, dmaaddr, ring->rx_buffersize);
  64  }
  65
  66  void b43_dma_rx(struct b43_dmaring *ring)