target/linux/mediatek/patches-4.4/0069-net-mediatek-fix-stop-and-wakeup-of-queue.patch

   1 From 6f8bfdfe2984467177d2a88982517659ec09ab5d Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Tue, 29 Mar 2016 16:41:07 +0200
   4 Subject: [PATCH 69/81] net: mediatek: fix stop and wakeup of queue
   5
   6 The driver supports 2 MACs. Both run on the same DMA ring. If we go
   7 above/below the TX rings thershold value, we always need to wake/stop
   8 the queu of both devices. Not doing to can cause TX stalls and packet
   9 drops on one of the devices.
  10
  11 Signed-off-by: John Crispin <blogic@openwrt.org>
  12 ---
  13  drivers/net/ethernet/mediatek/mtk_eth_soc.c |   37 +++++++++++++++++++--------
  14  1 file changed, 27 insertions(+), 10 deletions(-)
  15
  16 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
  17 +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
  18 @@ -684,6 +684,28 @@ static inline int mtk_cal_txd_req(struct
  19         return nfrags;
  20  }
  21
  22 +static void mtk_wake_queue(struct mtk_eth *eth)
  23 +{
  24 +       int i;
  25 +
  26 +       for (i = 0; i < MTK_MAC_COUNT; i++) {
  27 +               if (!eth->netdev[i])
  28 +                       continue;
  29 +               netif_wake_queue(eth->netdev[i]);
  30 +       }
  31 +}
  32 +
  33 +static void mtk_stop_queue(struct mtk_eth *eth)
  34 +{
  35 +       int i;
  36 +
  37 +       for (i = 0; i < MTK_MAC_COUNT; i++) {
  38 +               if (!eth->netdev[i])
  39 +                       continue;
  40 +               netif_stop_queue(eth->netdev[i]);
  41 +       }
  42 +}
  43 +
  44  static int mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
  45  {
  46         struct mtk_mac *mac = netdev_priv(dev);
  47 @@ -695,7 +717,7 @@ static int mtk_start_xmit(struct sk_buff
  48
  49         tx_num = mtk_cal_txd_req(skb);
  50         if (unlikely(atomic_read(&ring->free_count) <= tx_num)) {
  51 -               netif_stop_queue(dev);
  52 +               mtk_stop_queue(eth);
  53                 netif_err(eth, tx_queued, dev,
  54                           "Tx Ring full when queue awake!\n");
  55                 return NETDEV_TX_BUSY;
  56 @@ -720,10 +742,10 @@ static int mtk_start_xmit(struct sk_buff
  57                 goto drop;
  58
  59         if (unlikely(atomic_read(&ring->free_count) <= ring->thresh)) {
  60 -               netif_stop_queue(dev);
  61 +               mtk_stop_queue(eth);
  62                 if (unlikely(atomic_read(&ring->free_count) >
  63                              ring->thresh))
  64 -                       netif_wake_queue(dev);
  65 +                       mtk_wake_queue(eth);
  66         }
  67
  68         return NETDEV_TX_OK;
  69 @@ -897,13 +919,8 @@ static int mtk_poll_tx(struct mtk_eth *e
  70         if (!total)
  71                 return 0;
  72
  73 -       for (i = 0; i < MTK_MAC_COUNT; i++) {
  74 -               if (!eth->netdev[i] ||
  75 -                   unlikely(!netif_queue_stopped(eth->netdev[i])))
  76 -                       continue;
  77 -               if (atomic_read(&ring->free_count) > ring->thresh)
  78 -                       netif_wake_queue(eth->netdev[i]);
  79 -       }
  80 +       if (atomic_read(&ring->free_count) > ring->thresh)
  81 +               mtk_wake_queue(eth);
  82
  83         return total;
  84  }