On Sat, Jul 18, 2020 at 05:32:14PM +0100, Jonathan McDowell wrote:
> This switch has a single max frame size configuration register, so we
> track the requested MTU for each port and apply the largest.
>
> v2:
> - Address review feedback from Vladimir Oltean
>
> Signed-off-by: Jonathan McDowell <nood...@earth.li>
> ---
I think there's still an open question on whether the slave_dev->mtu of
all other ports should be updated to reflect the new, potentially larger
value. But we could always update drivers after the fact, if that ever
becomes required.
Acked-by: Vladimir Oltean <olte...@gmail.com>
> drivers/net/dsa/qca8k.c | 31 +++++++++++++++++++++++++++++++
> drivers/net/dsa/qca8k.h | 3 +++
> 2 files changed, 34 insertions(+)
>
> diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
> index 4acad5fa0c84..a5566de82853 100644
> --- a/drivers/net/dsa/qca8k.c
> +++ b/drivers/net/dsa/qca8k.c
> @@ -670,6 +670,11 @@ qca8k_setup(struct dsa_switch *ds)
> }
> }
>
> + /* Setup our port MTUs to match power on defaults */
> + for (i = 0; i < QCA8K_NUM_PORTS; i++)
> + priv->port_mtu[i] = ETH_FRAME_LEN + ETH_FCS_LEN;
> + qca8k_write(priv, QCA8K_MAX_FRAME_SIZE, ETH_FRAME_LEN + ETH_FCS_LEN);
> +
> /* Flush the FDB table */
> qca8k_fdb_flush(priv);
>
> @@ -1098,6 +1103,30 @@ qca8k_port_disable(struct dsa_switch *ds, int port)
> priv->port_sts[port].enabled = 0;
> }
>
> +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[port] > mtu)
> + mtu = priv->port_mtu[port];
> +
> + /* Include L2 header / FCS length */
> + qca8k_write(priv, QCA8K_MAX_FRAME_SIZE, mtu + ETH_HLEN + ETH_FCS_LEN);
> +
> + return 0;
> +}
> +
> +static int
> +qca8k_port_max_mtu(struct dsa_switch *ds, int port)
> +{
> + return QCA8K_MAX_MTU;
> +}
> +
> static int
> qca8k_port_fdb_insert(struct qca8k_priv *priv, const u8 *addr,
> u16 port_mask, u16 vid)
> @@ -1174,6 +1203,8 @@ static const struct dsa_switch_ops qca8k_switch_ops = {
> .set_mac_eee = qca8k_set_mac_eee,
> .port_enable = qca8k_port_enable,
> .port_disable = qca8k_port_disable,
> + .port_change_mtu = qca8k_port_change_mtu,
> + .port_max_mtu = qca8k_port_max_mtu,
> .port_stp_state_set = qca8k_port_stp_state_set,
> .port_bridge_join = qca8k_port_bridge_join,
> .port_bridge_leave = qca8k_port_bridge_leave,
> diff --git a/drivers/net/dsa/qca8k.h b/drivers/net/dsa/qca8k.h
> index 10ef2bca2cde..31439396401c 100644
> --- a/drivers/net/dsa/qca8k.h
> +++ b/drivers/net/dsa/qca8k.h
> @@ -13,6 +13,7 @@
> #include <linux/gpio.h>
>
> #define QCA8K_NUM_PORTS 7
> +#define QCA8K_MAX_MTU 9000
>
> #define PHY_ID_QCA8337 0x004dd036
> #define QCA8K_ID_QCA8337 0x13
> @@ -58,6 +59,7 @@
> #define QCA8K_MDIO_MASTER_MAX_REG 32
> #define QCA8K_GOL_MAC_ADDR0 0x60
> #define QCA8K_GOL_MAC_ADDR1 0x64
> +#define QCA8K_MAX_FRAME_SIZE 0x78
> #define QCA8K_REG_PORT_STATUS(_i) (0x07c + (_i) * 4)
> #define QCA8K_PORT_STATUS_SPEED GENMASK(1, 0)
> #define QCA8K_PORT_STATUS_SPEED_10 0
> @@ -189,6 +191,7 @@ struct qca8k_priv {
> struct device *dev;
> struct dsa_switch_ops ops;
> struct gpio_desc *reset_gpio;
> + unsigned int port_mtu[QCA8K_NUM_PORTS];
> };
>
> struct qca8k_mib_desc {
> --
> 2.27.0
>
