net: dsa: qca8k: drop MTU tracking from qca8k_priv

DSA set the CPU port based on the largest MTU of all the slave ports.
Based on this we can drop the MTU array from qca8k_priv and set the
port_change_mtu logic on DSA changing MTU of the CPU port as the switch
have a global MTU settingfor each port.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index d3ed0a7..4e27d98 100644 (file)
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -2367,16 +2367,18 @@ static int
 qca8k_port_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
 {
        struct qca8k_priv *priv = ds->priv;
-       int i, mtu = 0;
 
-       priv->port_mtu[port] = new_mtu;
-
-       for (i = 0; i < QCA8K_NUM_PORTS; i++)
-               if (priv->port_mtu[i] > mtu)
-                       mtu = priv->port_mtu[i];
+       /* We have only have a general MTU setting.
+        * DSA always set the CPU port's MTU to the largest MTU of the slave
+        * ports.
+        * Setting MTU just for the CPU port is sufficient to correctly set a
+        * value for every port.
+        */
+       if (!dsa_is_cpu_port(ds, port))
+               return 0;
 
        /* Include L2 header / FCS length */
-       return qca8k_write(priv, QCA8K_MAX_FRAME_SIZE, mtu + ETH_HLEN + ETH_FCS_LEN);
+       return qca8k_write(priv, QCA8K_MAX_FRAME_SIZE, new_mtu + ETH_HLEN + ETH_FCS_LEN);
 }
 
 static int
@@ -3033,16 +3035,6 @@ qca8k_setup(struct dsa_switch *ds)
                                  QCA8K_PORT_HOL_CTRL1_WRED_EN,
                                  mask);
                }
-
-               /* Set initial MTU for every port.
-                * We have only have a general MTU setting. So track
-                * every port and set the max across all port.
-                * Set per port MTU to 1500 as the MTU change function
-                * will add the overhead and if its set to 1518 then it
-                * will apply the overhead again and we will end up with
-                * MTU of 1536 instead of 1518
-                */
-               priv->port_mtu[i] = ETH_DATA_LEN;
        }
 
        /* Special GLOBAL_FC_THRESH value are needed for ar8327 switch */

diff --git a/drivers/net/dsa/qca8k.h b/drivers/net/dsa/qca8k.h
index f375627..562d759 100644 (file)
--- a/drivers/net/dsa/qca8k.h
+++ b/drivers/net/dsa/qca8k.h
@@ -398,7 +398,6 @@ struct qca8k_priv {
        struct device *dev;
        struct dsa_switch_ops ops;
        struct gpio_desc *reset_gpio;
-       unsigned int port_mtu[QCA8K_NUM_PORTS];
        struct net_device *mgmt_master; /* Track if mdio/mib Ethernet is available */
        struct qca8k_mgmt_eth_data mgmt_eth_data;
        struct qca8k_mib_eth_data mib_eth_data;