target/linux/mvebu/patches-4.4/050-net-mvneta-fix-changing-MTU-when-using-per-cpu-proce.patch

   1 From: Marcin Wojtas <mw@semihalf.com>
   2 Date: Fri, 1 Apr 2016 15:21:18 +0200
   3 Subject: [PATCH] net: mvneta: fix changing MTU when using per-cpu processing
   4
   5 After enabling per-cpu processing it appeared that under heavy load
   6 changing MTU can result in blocking all port's interrupts and
   7 transmitting data is not possible after the change.
   8
   9 This commit fixes above issue by disabling percpu interrupts for the
  10 time, when TXQs and RXQs are reconfigured.
  11
  12 Signed-off-by: Marcin Wojtas <mw@semihalf.com>
  13 Signed-off-by: David S. Miller <davem@davemloft.net>
  14 ---
  15
  16 --- a/drivers/net/ethernet/marvell/mvneta.c
  17 +++ b/drivers/net/ethernet/marvell/mvneta.c
  18 @@ -3040,6 +3040,20 @@ static int mvneta_check_mtu_valid(struct
  19         return mtu;
  20  }
  21
  22 +static void mvneta_percpu_enable(void *arg)
  23 +{
  24 +       struct mvneta_port *pp = arg;
  25 +
  26 +       enable_percpu_irq(pp->dev->irq, IRQ_TYPE_NONE);
  27 +}
  28 +
  29 +static void mvneta_percpu_disable(void *arg)
  30 +{
  31 +       struct mvneta_port *pp = arg;
  32 +
  33 +       disable_percpu_irq(pp->dev->irq);
  34 +}
  35 +
  36  /* Change the device mtu */
  37  static int mvneta_change_mtu(struct net_device *dev, int mtu)
  38  {
  39 @@ -3064,6 +3078,7 @@ static int mvneta_change_mtu(struct net_
  40          * reallocation of the queues
  41          */
  42         mvneta_stop_dev(pp);
  43 +       on_each_cpu(mvneta_percpu_disable, pp, true);
  44
  45         mvneta_cleanup_txqs(pp);
  46         mvneta_cleanup_rxqs(pp);
  47 @@ -3087,6 +3102,7 @@ static int mvneta_change_mtu(struct net_
  48                 return ret;
  49         }
  50
  51 +       on_each_cpu(mvneta_percpu_enable, pp, true);
  52         mvneta_start_dev(pp);
  53         mvneta_port_up(pp);
  54
  55 @@ -3240,20 +3256,6 @@ static void mvneta_mdio_remove(struct mv
  56         pp->phy_dev = NULL;
  57  }
  58
  59 -static void mvneta_percpu_enable(void *arg)
  60 -{
  61 -       struct mvneta_port *pp = arg;
  62 -
  63 -       enable_percpu_irq(pp->dev->irq, IRQ_TYPE_NONE);
  64 -}
  65 -
  66 -static void mvneta_percpu_disable(void *arg)
  67 -{
  68 -       struct mvneta_port *pp = arg;
  69 -
  70 -       disable_percpu_irq(pp->dev->irq);
  71 -}
  72 -
  73  /* Electing a CPU must be done in an atomic way: it should be done
  74   * after or before the removal/insertion of a CPU and this function is
  75   * not reentrant.