target/linux/ipq806x/patches-5.15/700-Revert-net-stmmac-Use-hrtimer-for-TX-coalescing.patch

   1 From 0db3e9ac75b107d2158b227426f58df9bb00529f Mon Sep 17 00:00:00 2001
   2 From: Oskari Lemmela <oskari@lemmela.net>
   3 Date: Sun, 20 Aug 2023 15:25:09 +0300
   4 Subject: [PATCH] Revert "net: stmmac: Use hrtimer for TX coalescing"
   5
   6 This reverts commit d5a05e69ac6e4c431c380ced2b534c91f7bc3280.
   7
   8 hrtimer uses raw_spin_lock which causes high CPU usage.
   9 ipq806x platform's TCP transmit speed dropped from 950 Mbps to 250 Mbps
  10 due to high ksoftirq.
  11
  12 Signed-off-by: Oskari Lemmela <oskari@lemmela.net>
  13 ---
  14  drivers/net/ethernet/stmicro/stmmac/stmmac.h  |  3 +--
  15  .../net/ethernet/stmicro/stmmac/stmmac_main.c | 25 +++++++------------
  16  2 files changed, 10 insertions(+), 18 deletions(-)
  17
  18 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
  19 +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
  20 @@ -13,7 +13,6 @@
  21  #define DRV_MODULE_VERSION     "Jan_2016"
  22
  23  #include <linux/clk.h>
  24 -#include <linux/hrtimer.h>
  25  #include <linux/if_vlan.h>
  26  #include <linux/stmmac.h>
  27  #include <linux/phylink.h>
  28 @@ -59,7 +58,7 @@ struct stmmac_tx_info {
  29  struct stmmac_tx_queue {
  30         u32 tx_count_frames;
  31         int tbs;
  32 -       struct hrtimer txtimer;
  33 +       struct timer_list txtimer;
  34         u32 queue_index;
  35         struct stmmac_priv *priv_data;
  36         struct dma_extended_desc *dma_etx ____cacheline_aligned_in_smp;
  37 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
  38 +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
  39 @@ -142,7 +142,7 @@ static void stmmac_init_fs(struct net_de
  40  static void stmmac_exit_fs(struct net_device *dev);
  41  #endif
  42
  43 -#define STMMAC_COAL_TIMER(x) (ns_to_ktime((x) * NSEC_PER_USEC))
  44 +#define STMMAC_COAL_TIMER(x) (jiffies + usecs_to_jiffies(x))
  45
  46  int stmmac_bus_clks_config(struct stmmac_priv *priv, bool enabled)
  47  {
  48 @@ -2726,9 +2726,7 @@ static int stmmac_tx_clean(struct stmmac
  49
  50         /* We still have pending packets, let's call for a new scheduling */
  51         if (tx_q->dirty_tx != tx_q->cur_tx)
  52 -               hrtimer_start(&tx_q->txtimer,
  53 -                             STMMAC_COAL_TIMER(priv->tx_coal_timer[queue]),
  54 -                             HRTIMER_MODE_REL);
  55 +               mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(priv->tx_coal_timer[queue]));
  56
  57         __netif_tx_unlock_bh(netdev_get_tx_queue(priv->dev, queue));
  58
  59 @@ -3020,9 +3018,7 @@ static void stmmac_tx_timer_arm(struct s
  60  {
  61         struct stmmac_tx_queue *tx_q = &priv->dma_conf.tx_queue[queue];
  62
  63 -       hrtimer_start(&tx_q->txtimer,
  64 -                     STMMAC_COAL_TIMER(priv->tx_coal_timer[queue]),
  65 -                     HRTIMER_MODE_REL);
  66 +       mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(priv->tx_coal_timer[queue]));
  67  }
  68
  69  /**
  70 @@ -3031,9 +3027,9 @@ static void stmmac_tx_timer_arm(struct s
  71   * Description:
  72   * This is the timer handler to directly invoke the stmmac_tx_clean.
  73   */
  74 -static enum hrtimer_restart stmmac_tx_timer(struct hrtimer *t)
  75 +static void stmmac_tx_timer(struct timer_list *t)
  76  {
  77 -       struct stmmac_tx_queue *tx_q = container_of(t, struct stmmac_tx_queue, txtimer);
  78 +       struct stmmac_tx_queue *tx_q = from_timer(tx_q, t, txtimer);
  79         struct stmmac_priv *priv = tx_q->priv_data;
  80         struct stmmac_channel *ch;
  81         struct napi_struct *napi;
  82 @@ -3049,8 +3045,6 @@ static enum hrtimer_restart stmmac_tx_ti
  83                 spin_unlock_irqrestore(&ch->lock, flags);
  84                 __napi_schedule(napi);
  85         }
  86 -
  87 -       return HRTIMER_NORESTART;
  88  }
  89
  90  /**
  91 @@ -3073,8 +3067,7 @@ static void stmmac_init_coalesce(struct
  92                 priv->tx_coal_frames[chan] = STMMAC_TX_FRAMES;
  93                 priv->tx_coal_timer[chan] = STMMAC_COAL_TX_TIMER;
  94
  95 -               hrtimer_init(&tx_q->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
  96 -               tx_q->txtimer.function = stmmac_tx_timer;
  97 +               timer_setup(&tx_q->txtimer, stmmac_tx_timer, 0);
  98         }
  99
 100         for (chan = 0; chan < rx_channel_count; chan++)
 101 @@ -3904,7 +3897,7 @@ irq_error:
 102         phylink_stop(priv->phylink);
 103
 104         for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
 105 -               hrtimer_cancel(&priv->dma_conf.tx_queue[chan].txtimer);
 106 +               del_timer_sync(&priv->dma_conf.tx_queue[chan].txtimer);
 107
 108         stmmac_hw_teardown(dev);
 109  init_error:
 110 @@ -3960,7 +3953,7 @@ static int stmmac_release(struct net_dev
 111         stmmac_disable_all_queues(priv);
 112
 113         for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
 114 -               hrtimer_cancel(&priv->dma_conf.tx_queue[chan].txtimer);
 115 +               del_timer_sync(&priv->dma_conf.tx_queue[chan].txtimer);
 116
 117         netif_tx_disable(dev);
 118
 119 @@ -6635,7 +6628,7 @@ void stmmac_xdp_release(struct net_devic
 120         stmmac_disable_all_queues(priv);
 121
 122         for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
 123 -               hrtimer_cancel(&priv->dma_conf.tx_queue[chan].txtimer);
 124 +               del_timer_sync(&priv->dma_conf.tx_queue[chan].txtimer);
 125
 126         /* Free the IRQ lines */
 127         stmmac_free_irq(dev, REQ_IRQ_ERR_ALL, 0);
 128 @@ -6730,8 +6723,7 @@ int stmmac_xdp_open(struct net_device *d
 129                 stmmac_set_tx_tail_ptr(priv, priv->ioaddr,
 130                                        tx_q->tx_tail_addr, chan);
 131
 132 -               hrtimer_init(&tx_q->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 133 -               tx_q->txtimer.function = stmmac_tx_timer;
 134 +               timer_setup(&tx_q->txtimer, stmmac_tx_timer, 0);
 135         }
 136
 137         /* Enable the MAC Rx/Tx */
 138 @@ -6754,7 +6746,7 @@ int stmmac_xdp_open(struct net_device *d
 139
 140  irq_error:
 141         for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
 142 -               hrtimer_cancel(&priv->dma_conf.tx_queue[chan].txtimer);
 143 +               del_timer_sync(&priv->dma_conf.tx_queue[chan].txtimer);
 144
 145         stmmac_hw_teardown(dev);
 146  init_error:
 147 @@ -7481,7 +7473,7 @@ int stmmac_suspend(struct device *dev)
 148         stmmac_disable_all_queues(priv);
 149
 150         for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
 151 -               hrtimer_cancel(&priv->dma_conf.tx_queue[chan].txtimer);
 152 +               del_timer_sync(&priv->dma_conf.tx_queue[chan].txtimer);
 153
 154         if (priv->eee_enabled) {
 155                 priv->tx_path_in_lpi_mode = false;