From 777e55e30d1275e0ddd70efdbcd8cf6f4dae554e Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Wed, 4 Aug 2021 16:54:34 +0300 Subject: [PATCH] net: dsa: sja1105: increase MTU to account for VLAN header on DSA ports Since all packets are transmitted as VLAN-tagged over a DSA link (this VLAN tag represents the tag_8021q header), we need to increase the MTU of these interfaces to account for the possibility that we are already transporting a user-visible VLAN header. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller --- drivers/net/dsa/sja1105/sja1105_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c index d1d4d956cae8..fffcaef6b148 100644 --- a/drivers/net/dsa/sja1105/sja1105_main.c +++ b/drivers/net/dsa/sja1105/sja1105_main.c @@ -982,7 +982,7 @@ static int sja1105_init_l2_policing(struct sja1105_private *priv) for (port = 0; port < ds->num_ports; port++) { int mtu = VLAN_ETH_FRAME_LEN + ETH_FCS_LEN; - if (dsa_is_cpu_port(priv->ds, port)) + if (dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port)) mtu += VLAN_HLEN; policing[port].smax = 65535; /* Burst size in bytes */ @@ -2664,7 +2664,7 @@ static int sja1105_change_mtu(struct dsa_switch *ds, int port, int new_mtu) new_mtu += VLAN_ETH_HLEN + ETH_FCS_LEN; - if (dsa_is_cpu_port(ds, port)) + if (dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port)) new_mtu += VLAN_HLEN; policing = priv->static_config.tables[BLK_IDX_L2_POLICING].entries; -- 2.11.0