From 5f4a8ef384db1e1e1d6132e3fac9c43fe670a4e8 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Sat, 5 Sep 2020 23:59:14 +0200 Subject: net: dsa: rtl8366rb: Support setting MTU This implements the missing MTU setting for the RTL8366RB switch. Apart from supporting jumboframes, this rids us of annoying boot messages like this: realtek-smi switch: nonfatal error -95 setting MTU on port 0 Signed-off-by: Linus Walleij Reviewed-by: Florian Fainelli Signed-off-by: Jakub Kicinski --- drivers/net/dsa/rtl8366rb.c | 38 +++++++++++++++++++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) (limited to 'drivers/net/dsa/rtl8366rb.c') diff --git a/drivers/net/dsa/rtl8366rb.c b/drivers/net/dsa/rtl8366rb.c index 48f1ff746799..f763f93f600f 100644 --- a/drivers/net/dsa/rtl8366rb.c +++ b/drivers/net/dsa/rtl8366rb.c @@ -35,7 +35,7 @@ #define RTL8366RB_SGCR_MAX_LENGTH_1522 RTL8366RB_SGCR_MAX_LENGTH(0x0) #define RTL8366RB_SGCR_MAX_LENGTH_1536 RTL8366RB_SGCR_MAX_LENGTH(0x1) #define RTL8366RB_SGCR_MAX_LENGTH_1552 RTL8366RB_SGCR_MAX_LENGTH(0x2) -#define RTL8366RB_SGCR_MAX_LENGTH_9216 RTL8366RB_SGCR_MAX_LENGTH(0x3) +#define RTL8366RB_SGCR_MAX_LENGTH_16000 RTL8366RB_SGCR_MAX_LENGTH(0x3) #define RTL8366RB_SGCR_EN_VLAN BIT(13) #define RTL8366RB_SGCR_EN_VLAN_4KTB BIT(14) @@ -1077,6 +1077,40 @@ rtl8366rb_port_disable(struct dsa_switch *ds, int port) rb8366rb_set_port_led(smi, port, false); } +static int rtl8366rb_change_mtu(struct dsa_switch *ds, int port, int new_mtu) +{ + struct realtek_smi *smi = ds->priv; + u32 len; + + /* The first setting, 1522 bytes, is max IP packet 1500 bytes, + * plus ethernet header, 1518 bytes, plus CPU tag, 4 bytes. + * This function should consider the parameter an SDU, so the + * MTU passed for this setting is 1518 bytes. The same logic + * of subtracting the DSA tag of 4 bytes apply to the other + * settings. + */ + if (new_mtu <= 1518) + len = RTL8366RB_SGCR_MAX_LENGTH_1522; + else if (new_mtu > 1518 && new_mtu <= 1532) + len = RTL8366RB_SGCR_MAX_LENGTH_1536; + else if (new_mtu > 1532 && new_mtu <= 1548) + len = RTL8366RB_SGCR_MAX_LENGTH_1552; + else + len = RTL8366RB_SGCR_MAX_LENGTH_16000; + + return regmap_update_bits(smi->map, RTL8366RB_SGCR, + RTL8366RB_SGCR_MAX_LENGTH_MASK, + len); +} + +static int rtl8366rb_max_mtu(struct dsa_switch *ds, int port) +{ + /* The max MTU is 16000 bytes, so we subtract the CPU tag + * and the max presented to the system is 15996 bytes. + */ + return 15996; +} + static int rtl8366rb_get_vlan_4k(struct realtek_smi *smi, u32 vid, struct rtl8366_vlan_4k *vlan4k) { @@ -1415,6 +1449,8 @@ static const struct dsa_switch_ops rtl8366rb_switch_ops = { .port_vlan_del = rtl8366_vlan_del, .port_enable = rtl8366rb_port_enable, .port_disable = rtl8366rb_port_disable, + .port_change_mtu = rtl8366rb_change_mtu, + .port_max_mtu = rtl8366rb_max_mtu, }; static const struct realtek_smi_ops rtl8366rb_smi_ops = { -- cgit