[PATCH net-next v2 09/12] ax88179_178a: Add VLAN offload support for AX88179A

From: Birger Koblitz

Date: Wed Jul 08 2026 - 14:46:43 EST


The AX88179A-based chips support VLAN offload. Add configuration
support in netdev_ops. Features supported are:
NETIF_F_HW_VLAN_CTAG_TX, NETIF_F_HW_VLAN_CTAG_RX
and NETIF_F_HW_VLAN_CTAG_FILTER.

Signed-off-by: Birger Koblitz <mail@xxxxxxxxxxxxxxxxx>
---
drivers/net/usb/ax88179_178a.c | 87 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 87 insertions(+)

diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index 925b66f8b8fff10578056bb13e15dc4ba0f88ecc..519d01e80f938346b6c8742be36b70ae31bc2855 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -1195,6 +1195,62 @@ static const struct ethtool_ops ax88179_ethtool_ops = {
.get_ts_info = ethtool_op_get_ts_info,
};

+static int ax179a_vlan_rx_kill_vid(struct net_device *net, __be16 proto, u16 vid)
+{
+ struct usbnet *dev = netdev_priv(net);
+ u8 vlan_ctrl;
+ u16 reg16;
+ u8 reg8;
+
+ ax88179_read_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_CONTROL, 1, 1, &reg8);
+ vlan_ctrl = reg8;
+
+ /* Address */
+ reg8 = (vid / 16);
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_ADDRESS, 1, 1, &reg8);
+
+ /* Data */
+ reg8 = vlan_ctrl | AX_VLAN_CONTROL_RD;
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_CONTROL, 1, 1, &reg8);
+
+ ax88179_read_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_DATA0, 2, 2, &reg16);
+ reg16 &= ~(1 << (vid % 16));
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_DATA0, 2, 2, &reg16);
+
+ reg8 = vlan_ctrl | AX_VLAN_CONTROL_WE;
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_CONTROL, 1, 1, &reg8);
+
+ return 0;
+}
+
+static int ax179a_vlan_rx_add_vid(struct net_device *net, __be16 proto, u16 vid)
+{
+ struct usbnet *dev = netdev_priv(net);
+ u8 vlan_ctrl;
+ u16 reg16;
+ u8 reg8;
+
+ ax88179_read_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_CONTROL, 1, 1, &reg8);
+ vlan_ctrl = reg8;
+
+ /* Address */
+ reg8 = (vid / 16);
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_ADDRESS, 1, 1, &reg8);
+
+ /* Data */
+ reg8 = vlan_ctrl | AX_VLAN_CONTROL_RD;
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_CONTROL, 1, 1, &reg8);
+
+ ax88179_read_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_DATA0, 2, 2, &reg16);
+ reg16 |= (1 << (vid % 16));
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_DATA0, 2, 2, &reg16);
+
+ reg8 = vlan_ctrl | AX_VLAN_CONTROL_WE;
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_CONTROL, 1, 1, &reg8);
+
+ return 0;
+}
+
static void ax88179_set_multicast(struct net_device *net)
{
struct usbnet *dev = netdev_priv(net);
@@ -1240,6 +1296,7 @@ ax88179_set_features(struct net_device *net, netdev_features_t features)
{
u8 tmp;
struct usbnet *dev = netdev_priv(net);
+ struct ax88179_data *data = dev->driver_priv;
netdev_features_t changed = net->features ^ features;

if (changed & NETIF_F_IP_CSUM) {
@@ -1259,6 +1316,34 @@ ax88179_set_features(struct net_device *net, netdev_features_t features)
tmp ^= AX_RXCOE_IP | AX_RXCOE_TCP | AX_RXCOE_UDP |
AX_RXCOE_TCPV6 | AX_RXCOE_UDPV6;
ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_RXCOE_CTL, 1, 1, &tmp);
+ data->rx_checksum = !!(features & NETIF_F_RXCSUM);
+ }
+
+ if (changed & NETIF_F_HW_VLAN_CTAG_FILTER) {
+ ax88179_read_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_CONTROL, 1, 1, &tmp);
+ tmp ^= AX_VLAN_CONTROL_VFE;
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_CONTROL, 1, 1, &tmp);
+ if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
+ for (int i = 0; i < 256; i++) {
+ u16 tmp16 = 0;
+ /* Address */
+ tmp = i;
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_ADDRESS,
+ 1, 1, &tmp);
+ /* Data */
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_DATA0,
+ 2, 2, &tmp16);
+ tmp = AX_VLAN_CONTROL_WE;
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_CONTROL,
+ 1, 1, &tmp);
+ }
+ }
+ }
+
+ if (changed & NETIF_F_HW_VLAN_CTAG_RX) {
+ ax88179_read_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_CONTROL, 1, 1, &tmp);
+ tmp ^= AX_VLAN_CONTROL_VSO;
+ ax88179_write_cmd(dev, AX_ACCESS_MAC, AX88179A_VLAN_ID_CONTROL, 1, 1, &tmp);
}

return 0;
@@ -1326,6 +1411,8 @@ static const struct net_device_ops ax88179_netdev_ops = {
.ndo_eth_ioctl = usbnet_mii_ioctl,
.ndo_set_rx_mode = ax88179_set_multicast,
.ndo_set_features = ax88179_set_features,
+ .ndo_vlan_rx_add_vid = ax179a_vlan_rx_add_vid,
+ .ndo_vlan_rx_kill_vid = ax179a_vlan_rx_kill_vid,
};

static int ax88179_check_eeprom(struct usbnet *dev)

--
2.47.3