target/linux/generic/pending-5.4/770-10-net-ethernet-mtk_eth_soc-unmap-rx-data-before-callin.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Thu, 27 Aug 2020 09:44:43 +0200
   3 Subject: [PATCH] net: ethernet: mtk_eth_soc: unmap rx data before calling
   4  build_skb
   5
   6 Since build_skb accesses the data area (for initializing shinfo), dma unmap
   7 needs to happen before that call
   8
   9 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  10 ---
  11
  12 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
  13 +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
  14 @@ -1293,17 +1293,18 @@ static int mtk_poll_rx(struct napi_struc
  15                         goto release_desc;
  16                 }
  17
  18 +               dma_unmap_single(eth->dev, trxd.rxd1,
  19 +                                ring->buf_size, DMA_FROM_DEVICE);
  20 +
  21                 /* receive data */
  22                 skb = build_skb(data, ring->frag_size);
  23                 if (unlikely(!skb)) {
  24 -                       skb_free_frag(new_data);
  25 +                       skb_free_frag(data);
  26                         netdev->stats.rx_dropped++;
  27 -                       goto release_desc;
  28 +                       goto skip_rx;
  29                 }
  30                 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
  31
  32 -               dma_unmap_single(eth->dev, trxd.rxd1,
  33 -                                ring->buf_size, DMA_FROM_DEVICE);
  34                 pktlen = RX_DMA_GET_PLEN0(trxd.rxd2);
  35                 skb->dev = netdev;
  36                 skb_put(skb, pktlen);
  37 @@ -1321,6 +1322,7 @@ static int mtk_poll_rx(struct napi_struc
  38                 skb_record_rx_queue(skb, 0);
  39                 napi_gro_receive(napi, skb);
  40
  41 +skip_rx:
  42                 ring->data[idx] = new_data;
  43                 rxd->rxd1 = (unsigned int)dma_addr;
  44