Commit 5f4a8ef3 authored by Linus Walleij's avatar Linus Walleij Committed by Jakub Kicinski
Browse files

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: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 383e3f3e

drivers/net/dsa/rtl8366rb.c

+37 −1
Original line number Diff line number Diff line
@@ -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 = {

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