From 69fd055957a02309ffdc23d887a01988b6e5bab1 Mon Sep 17 00:00:00 2001 From: Ansuel Smith Date: Sat, 16 Apr 2022 01:30:12 +0200 Subject: [PATCH 1/6] 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 Reviewed-by: Vladimir Oltean Signed-off-by: David S. Miller --- drivers/net/dsa/qca8k.c | 26 +++++++++----------------- drivers/net/dsa/qca8k.h | 1 - 2 files changed, 9 insertions(+), 18 deletions(-) --- a/drivers/net/dsa/qca8k.c +++ b/drivers/net/dsa/qca8k.c @@ -1803,16 +1803,6 @@ 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 */ @@ -2525,13 +2515,16 @@ static int qca8k_port_change_mtu(struct dsa_switch *ds, int port, int new_mtu) { struct qca8k_priv *priv = ds->priv; - int ret, i, mtu = 0; - - priv->port_mtu[port] = new_mtu; + int ret; - 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; /* To change the MAX_FRAME_SIZE the cpu ports must be off or * the switch panics. @@ -2545,7 +2538,7 @@ qca8k_port_change_mtu(struct dsa_switch qca8k_port_set_status(priv, 6, 0); /* Include L2 header / FCS length */ - ret = qca8k_write(priv, QCA8K_MAX_FRAME_SIZE, mtu + ETH_HLEN + ETH_FCS_LEN); + ret = qca8k_write(priv, QCA8K_MAX_FRAME_SIZE, new_mtu + ETH_HLEN + ETH_FCS_LEN); if (priv->port_sts[0].enabled) qca8k_port_set_status(priv, 0, 1); --- a/drivers/net/dsa/qca8k.h +++ b/drivers/net/dsa/qca8k.h @@ -392,7 +392,6 @@ 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;