Re: [PATCH net-next v2 07/10] net: fec: fec_enet_rx_queue(): replace manual VLAN header calculation with skb_vlan_eth_hdr()

[Andrew Lunn]

On Thu, Jun 12, 2025 at 04:16:00PM +0200, Marc Kleine-Budde wrote:
> Use the provided helper function skb_vlan_eth_hdr() to replace manual VLAN
> header calculation for better readability and maintainability.
> 
> Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> Reviewed-by: Wei Fang <wei.fang@xxxxxxx>
> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> ---
>  drivers/net/ethernet/freescale/fec_main.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
> index 6b456372de9a..f238cb60aa65 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -1860,8 +1860,7 @@ fec_enet_rx_queue(struct net_device *ndev, u16 queue_id, int budget)
>  		    fep->bufdesc_ex &&
>  		    (ebdp->cbd_esc & cpu_to_fec32(BD_ENET_RX_VLAN))) {
>  			/* Push and remove the vlan tag */
> -			struct vlan_hdr *vlan_header =
> -					(struct vlan_hdr *) (data + ETH_HLEN);
> +			struct vlan_ethhdr *vlan_header = skb_vlan_eth_hdr(skb);

This is not 'obviously correct', so probably the commit message needs
expanding.

static inline struct vlan_ethhdr *skb_vlan_eth_hdr(const struct sk_buff *skb)
{
	return (struct vlan_ethhdr *)skb->data;
}

I can see a few lines early:

		data = skb->data;

but what about the + ETH_HLEN?

	Andrew