mlx4_en: Coalescing target is equal for all mtu's

The interrupt moderation should not depend on number of incoming
bytes, but on number of incoming packets.
The previous scheme caused very high interrupts rate for small
messages when big MTU was configured.

Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 4 insertions, 5 deletions

diff --git a/drivers/net/mlx4/en_ethtool.c b/drivers/net/mlx4/en_ethtool.c
index 91d81169e04..091f99052c9 100644
--- a/drivers/net/mlx4/en_ethtool.c
+++ b/drivers/net/mlx4/en_ethtool.c
@@ -268,8 +268,7 @@ static int mlx4_en_set_coalesce(struct net_device *dev,
 
         priv->rx_frames = (coal->rx_max_coalesced_frames ==
                            MLX4_EN_AUTO_CONF) ?
-                                MLX4_EN_RX_COAL_TARGET /
-                                priv->dev->mtu + 1 :
+                                MLX4_EN_RX_COAL_TARGET :
                                 coal->rx_max_coalesced_frames;
         priv->rx_usecs = (coal->rx_coalesce_usecs ==
                           MLX4_EN_AUTO_CONF) ?
diff --git a/drivers/net/mlx4/en_netdev.c b/drivers/net/mlx4/en_netdev.c
index fea65e78d6d..16a634ffbcd 100644
--- a/drivers/net/mlx4/en_netdev.c
+++ b/drivers/net/mlx4/en_netdev.c
@@ -372,7 +372,7 @@ static void mlx4_en_set_default_moderation(struct mlx4_en_priv *priv)
          *   satisfy our coelsing target.
          * - moder_time is set to a fixed value.
          */
-        priv->rx_frames = MLX4_EN_RX_COAL_TARGET / priv->dev->mtu + 1;
+        priv->rx_frames = MLX4_EN_RX_COAL_TARGET;
         priv->rx_usecs = MLX4_EN_RX_COAL_TIME;
         en_dbg(INTR, priv, "Default coalesing params for mtu:%d - "
                            "rx_frames:%d rx_usecs:%d\n",
diff --git a/drivers/net/mlx4/mlx4_en.h b/drivers/net/mlx4/mlx4_en.h
index 174ae86e952..fcbfcfc1156 100644
--- a/drivers/net/mlx4/mlx4_en.h
+++ b/drivers/net/mlx4/mlx4_en.h
@@ -143,8 +143,8 @@ enum {
 #define MLX4_EN_DEF_TX_RING_SIZE        1024
 #define MLX4_EN_DEF_RX_RING_SIZE        1024
 
-/* Target number of bytes to coalesce with interrupt moderation */
-#define MLX4_EN_RX_COAL_TARGET  0x20000
+/* Target number of packets to coalesce with interrupt moderation */
+#define MLX4_EN_RX_COAL_TARGET  44
 #define MLX4_EN_RX_COAL_TIME    0x10
 
 #define MLX4_EN_TX_COAL_PKTS    5