Re: [REGRESSION][BISECTED] r8169: TX stall with checksum offload on VLAN frames with inline tag (REORDER_HDR off) since 1517d1996b52

Hi Eric,

On Wed, 7 Oct 2026 at 00:00, Eric Dumazet [off-list ref] wrote:

Note to testers:

My LLM agreed with the change in vlan_dev_hard_header() (above), but said
that no change was needed in vlan_dev_hard_start_xmit() (below)

I'll need the patch applied to 6.18.y for testing, as I can't test it
personally and I want to provide testers with the same kernel/system
version as before just with minimal changes. So do I understand
correctly that the patch below is what you want to get tested, no
changes in vlan_dev_hard_start_xmit()?

Regards,
Jan

diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 560521cf596e..67648152add8 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c

@@ -49,42 +49,14 @@ static int vlan_dev_hard_header(struct sk_buff

*skb, struct net_device *dev,
                                unsigned int len)
 {
        struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
-       struct vlan_hdr *vhdr;
-       unsigned int vhdrlen = 0;
-       u16 vlan_tci = 0;
-       int rc;
-
-       if (!(vlan->flags & VLAN_FLAG_REORDER_HDR)) {
-               vhdr = skb_push(skb, VLAN_HLEN);
-
-               vlan_tci = vlan->vlan_id;
-               vlan_tci |= vlan_dev_get_egress_qos_mask(dev, skb->priority);
-               vhdr->h_vlan_TCI = htons(vlan_tci);
-
-               /*
-                *  Set the protocol type. For a packet of type ETH_P_802_3/2 we
-                *  put the length in here instead.
-                */
-               if (type != ETH_P_802_3 && type != ETH_P_802_2)
-                       vhdr->h_vlan_encapsulated_proto = htons(type);
-               else
-                       vhdr->h_vlan_encapsulated_proto = htons(len);
-
-               skb->protocol = vlan->vlan_proto;
-               type = ntohs(vlan->vlan_proto);
-               vhdrlen = VLAN_HLEN;
-       }
+       struct net_device *real_dev = vlan->real_dev;

        /* Before delegating work to the lower layer, enter our MAC-address */
        if (saddr == NULL)
                saddr = dev->dev_addr;

        /* Now make the underlying real hard header */
-       dev = vlan->real_dev;
-       rc = dev_hard_header(skb, dev, type, daddr, saddr, len + vhdrlen);
-       if (rc > 0)
-               rc += vhdrlen;
-       return rc;
+       return dev_hard_header(skb, real_dev, type, daddr, saddr, len);
 }

 static inline netdev_tx_t vlan_netpoll_send_skb(struct vlan_dev_priv
*vlan, struct sk_buff *skb)