target/linux/generic/backport-6.1/771-v6.7-02-net-stmmac-move-TX-timer-arm-after-DMA-enable.patch

   1 From a594166387fe08e6f5a32130c400249a35b298f9 Mon Sep 17 00:00:00 2001
   2 From: Christian Marangi <ansuelsmth@gmail.com>
   3 Date: Wed, 18 Oct 2023 14:35:49 +0200
   4 Subject: [PATCH 2/3] net: stmmac: move TX timer arm after DMA enable
   5
   6 Move TX timer arm call after DMA interrupt is enabled again.
   7
   8 The TX timer arm function changed logic and now is skipped if a napi is
   9 already scheduled. By moving the TX timer arm call after DMA is enabled,
  10 we permit to correctly skip if a DMA interrupt has been fired and a napi
  11 has been scheduled again.
  12
  13 Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  14 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
  15 ---
  16  .../net/ethernet/stmicro/stmmac/stmmac_main.c | 22 +++++++++++++++----
  17  1 file changed, 18 insertions(+), 4 deletions(-)
  18
  19 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
  20 +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
  21 @@ -2527,9 +2527,13 @@ static void stmmac_bump_dma_threshold(st
  22   * @priv: driver private structure
  23   * @budget: napi budget limiting this functions packet handling
  24   * @queue: TX queue index
  25 + * @pending_packets: signal to arm the TX coal timer
  26   * Description: it reclaims the transmit resources after transmission completes.
  27 + * If some packets still needs to be handled, due to TX coalesce, set
  28 + * pending_packets to true to make NAPI arm the TX coal timer.
  29   */
  30 -static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue)
  31 +static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue,
  32 +                          bool *pending_packets)
  33  {
  34         struct stmmac_tx_queue *tx_q = &priv->dma_conf.tx_queue[queue];
  35         unsigned int bytes_compl = 0, pkts_compl = 0;
  36 @@ -2692,7 +2696,7 @@ static int stmmac_tx_clean(struct stmmac
  37
  38         /* We still have pending packets, let's call for a new scheduling */
  39         if (tx_q->dirty_tx != tx_q->cur_tx)
  40 -               stmmac_tx_timer_arm(priv, queue);
  41 +               *pending_packets = true;
  42
  43         __netif_tx_unlock_bh(netdev_get_tx_queue(priv->dev, queue));
  44
  45 @@ -5490,12 +5494,13 @@ static int stmmac_napi_poll_tx(struct na
  46         struct stmmac_channel *ch =
  47                 container_of(napi, struct stmmac_channel, tx_napi);
  48         struct stmmac_priv *priv = ch->priv_data;
  49 +       bool pending_packets = false;
  50         u32 chan = ch->index;
  51         int work_done;
  52
  53         priv->xstats.napi_poll++;
  54
  55 -       work_done = stmmac_tx_clean(priv, budget, chan);
  56 +       work_done = stmmac_tx_clean(priv, budget, chan, &pending_packets);
  57         work_done = min(work_done, budget);
  58
  59         if (work_done < budget && napi_complete_done(napi, work_done)) {
  60 @@ -5506,6 +5511,10 @@ static int stmmac_napi_poll_tx(struct na
  61                 spin_unlock_irqrestore(&ch->lock, flags);
  62         }
  63
  64 +       /* TX still have packet to handle, check if we need to arm tx timer */
  65 +       if (pending_packets)
  66 +               stmmac_tx_timer_arm(priv, chan);
  67 +
  68         return work_done;
  69  }
  70
  71 @@ -5514,12 +5523,13 @@ static int stmmac_napi_poll_rxtx(struct
  72         struct stmmac_channel *ch =
  73                 container_of(napi, struct stmmac_channel, rxtx_napi);
  74         struct stmmac_priv *priv = ch->priv_data;
  75 +       bool tx_pending_packets = false;
  76         int rx_done, tx_done, rxtx_done;
  77         u32 chan = ch->index;
  78
  79         priv->xstats.napi_poll++;
  80
  81 -       tx_done = stmmac_tx_clean(priv, budget, chan);
  82 +       tx_done = stmmac_tx_clean(priv, budget, chan, &tx_pending_packets);
  83         tx_done = min(tx_done, budget);
  84
  85         rx_done = stmmac_rx_zc(priv, budget, chan);
  86 @@ -5544,6 +5554,10 @@ static int stmmac_napi_poll_rxtx(struct
  87                 spin_unlock_irqrestore(&ch->lock, flags);
  88         }
  89
  90 +       /* TX still have packet to handle, check if we need to arm tx timer */
  91 +       if (tx_pending_packets)
  92 +               stmmac_tx_timer_arm(priv, chan);
  93 +
  94         return min(rxtx_done, budget - 1);
  95  }
  96