kernel: mtk_eth_soc: fix tx vlan tag for llc packets

When sending llc packets with vlan tx offload, the hardware fails to
actually add the tag. Deal with this by fixing it up in software.

Fixes: https://github.com/openwrt/openwrt/issues/19916
Reported-by: Thibaut VARENE <hacks@slashdirt.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
(cherry picked from commit f7d40365558f3426b85be35f1f2ba7d01df96dd0)
(cherry picked from commit 9de2da13bf5ee895e8acf5a83f910bbdef46f0d1)
This commit is contained in:
Felix Fietkau 2025-08-31 20:28:52 +02:00 committed by Hela Saadani
parent 88f62295ce
commit 2c0f88a06e

View File

@ -0,0 +1,39 @@
From: Felix Fietkau <nbd@nbd.name>
Date: Sun, 31 Aug 2025 20:05:13 +0200
Subject: [PATCH] net: ethernet: mtk_eth_soc: fix tx vlan tag for llc packets
When sending llc packets with vlan tx offload, the hardware fails to
actually add the tag. Deal with this by fixing it up in software.
Fixes: 656e705243fd ("net-next: mediatek: add support for MT7623 ethernet")
Reported-by: Thibaut VARENE <hacks@slashdirt.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1763,6 +1763,13 @@ static netdev_tx_t mtk_start_xmit(struct
bool gso = false;
int tx_num;
+ if (skb_vlan_tag_present(skb) &&
+ !eth_proto_is_802_3(eth_hdr(skb)->h_proto)) {
+ skb = __vlan_hwaccel_push_inside(skb);
+ if (!skb)
+ goto dropped;
+ }
+
/* normally we can rely on the stack not calling this more than once,
* however we have 2 queues running on the same ring so we need to lock
* the ring access
@@ -1826,8 +1833,9 @@ static netdev_tx_t mtk_start_xmit(struct
drop:
spin_unlock(&eth->page_lock);
- stats->tx_dropped++;
dev_kfree_skb_any(skb);
+dropped:
+ stats->tx_dropped++;
return NETDEV_TX_OK;
}