From: Andrew Lunn andrew@lunn.ch
[ Upstream commit b9c587fed61cf88bd45822c3159644445f6d5aa6 ]
Same members of the Marvell Ethernet switches impose MTU restrictions on ports used for connecting to the CPU or another switch for DSA. If the MTU is set too low, tagged frames will be discarded. Ensure the worst case tagger overhead is included in setting the MTU for DSA and CPU ports.
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/dsa/mv88e6xxx/chip.c | 9 ++++++--- drivers/net/dsa/mv88e6xxx/chip.h | 1 + 2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c index 014950a343f4..66b4f4a9832a 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.c +++ b/drivers/net/dsa/mv88e6xxx/chip.c @@ -2885,10 +2885,10 @@ 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 - VLAN_ETH_HLEN - ETH_FCS_LEN; + return 10240 - VLAN_ETH_HLEN - EDSA_HLEN - ETH_FCS_LEN; else if (chip->info->ops->set_max_frame_size) - return 1632 - VLAN_ETH_HLEN - ETH_FCS_LEN; - return 1522 - VLAN_ETH_HLEN - ETH_FCS_LEN; + return 1632 - VLAN_ETH_HLEN - EDSA_HLEN - ETH_FCS_LEN; + return 1522 - VLAN_ETH_HLEN - EDSA_HLEN - ETH_FCS_LEN; }
static int mv88e6xxx_change_mtu(struct dsa_switch *ds, int port, int new_mtu) @@ -2896,6 +2896,9 @@ static int mv88e6xxx_change_mtu(struct dsa_switch *ds, int port, int new_mtu) struct mv88e6xxx_chip *chip = ds->priv; int ret = 0;
+ if (dsa_is_dsa_port(ds, port) || dsa_is_cpu_port(ds, port)) + new_mtu += EDSA_HLEN; + mv88e6xxx_reg_lock(chip); if (chip->info->ops->port_set_jumbo_size) ret = chip->info->ops->port_set_jumbo_size(chip, port, new_mtu); diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h index 675b1f3e43b7..59f316cc8583 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.h +++ b/drivers/net/dsa/mv88e6xxx/chip.h @@ -18,6 +18,7 @@ #include <linux/timecounter.h> #include <net/dsa.h>
+#define EDSA_HLEN 8 #define MV88E6XXX_N_FID 4096
/* PVT limits for 4-bit port and 5-bit switch */