dsa: mv88e6xxx: Fix MTU definition

The MTU passed to the DSA driver is the payload size, typically 1500.
However, the switch uses the frame size when applying restrictions.
Adjust the MTU with the size of the Ethernet header and the frame
checksum. The VLAN header also needs to be included when the frame
size it per port, but not when it is global.

Fixes: 1baf0fac10fb ("net: dsa: mv88e6xxx: Use chip-wide max frame size for MTU")
Reported by: 曹煜 <cao88yu@gmail.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 86d3cab6ceef8622c71dd3200466fd6987c57a2e..ed4a6d18142b794a032a596b69c6b7c54782f6bb 100644 (file)
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -2834,8 +2834,8 @@ static int mv88e6xxx_setup_port(struct mv88e6xxx_chip *chip, int port)
        if (err)
                return err;
 
-       /* Port Control 2: don't force a good FCS, set the maximum frame size to
-        * 10240 bytes, disable 802.1q tags checking, don't discard tagged or
+       /* Port Control 2: don't force a good FCS, set the MTU size to
+        * 10222 bytes, disable 802.1q tags checking, don't discard tagged or
         * untagged frames on this port, do a destination address lookup on all
         * received packets as usual, disable ARP mirroring and don't send a
         * copy of all transmitted/received frames on this port to the CPU.
@@ -2854,7 +2854,7 @@ static int mv88e6xxx_setup_port(struct mv88e6xxx_chip *chip, int port)
                return err;
 
        if (chip->info->ops->port_set_jumbo_size) {
-               err = chip->info->ops->port_set_jumbo_size(chip, port, 10240);
+               err = chip->info->ops->port_set_jumbo_size(chip, port, 10218);
                if (err)
                        return err;
        }
@@ -2944,10 +2944,10 @@ static int mv88e6xxx_get_max_mtu(struct dsa_switch *ds, int port)
        struct mv88e6xxx_chip *chip = ds->priv;
 
        if (chip->info->ops->port_set_jumbo_size)
-               return 10240;
+               return 10240 - VLAN_ETH_HLEN - ETH_FCS_LEN;
        else if (chip->info->ops->set_max_frame_size)
-               return 1632;
-       return 1522;
+               return 1632 - VLAN_ETH_HLEN - ETH_FCS_LEN;
+       return 1522 - VLAN_ETH_HLEN - ETH_FCS_LEN;
 }
 
 static int mv88e6xxx_change_mtu(struct dsa_switch *ds, int port, int new_mtu)

diff --git a/drivers/net/dsa/mv88e6xxx/global1.c b/drivers/net/dsa/mv88e6xxx/global1.c
index 815b0f681d698fc75848a16861f32524083456b2..5848112036b08d90ea584f49d9146638ea695158 100644 (file)
--- a/drivers/net/dsa/mv88e6xxx/global1.c
+++ b/drivers/net/dsa/mv88e6xxx/global1.c
@@ -232,6 +232,8 @@ int mv88e6185_g1_set_max_frame_size(struct mv88e6xxx_chip *chip, int mtu)
        u16 val;
        int err;
 
+       mtu += ETH_HLEN + ETH_FCS_LEN;
+
        err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_CTL1, &val);
        if (err)
                return err;

diff --git a/drivers/net/dsa/mv88e6xxx/port.c b/drivers/net/dsa/mv88e6xxx/port.c
index f77e2ee64a607a8cae7c6c1c927c4a6f1a01d9b9..451028c57af8affc42716b8f1aed6cc3bce0c508 100644 (file)
--- a/drivers/net/dsa/mv88e6xxx/port.c
+++ b/drivers/net/dsa/mv88e6xxx/port.c
@@ -1277,6 +1277,8 @@ int mv88e6165_port_set_jumbo_size(struct mv88e6xxx_chip *chip, int port,
        u16 reg;
        int err;
 
+       size += VLAN_ETH_HLEN + ETH_FCS_LEN;
+
        err = mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_CTL2, &reg);
        if (err)
                return err;