Subject: Re: [PATCH v3] net: hyperv: add support for vlans in netvsc driver

From: Stephen Hemminger <[email-masked]>
Date: Mon, 20 Jul 2020 10:34:25 -0700

On Mon, 20 Jul 2020 22:15:51 +0530
Sriram Krishnan <[email-masked]> wrote:

>  
> +	/* When using AF_PACKET we need to remove VLAN from frame
> +	 * and indicate VLAN information in SKB so HOST OS will
> +	 * transmit the VLAN frame
> +	 */
> +	if (skb->protocol == htons(ETH_P_8021Q)) {
> +		u16 vlan_tci = 0;
> +		skb_reset_mac_header(skb);
> +		if (eth_type_vlan(eth_hdr(skb)->h_proto)) {
> +			int pop_err;
> +			pop_err = __skb_vlan_pop(skb, &vlan_tci);
> +			if (likely(pop_err == 0)) {
> +				__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tci);
> +
> +				/* Update the NDIS header pkt lengths */
> +				packet->total_data_buflen -= VLAN_HLEN;
> +				rndis_msg->msg_len = packet->total_data_buflen;
> +				rndis_msg->msg.pkt.data_len = packet->total_data_buflen;
> +
> +			} else {
> +				netdev_err(net,"Pop vlan err %x\n",pop_err);
> +			}
> +		}
> +	}

Minor comments.

1. Blank line between declaration and code.
2. Error handling is different than other parts of this code.
   probably just need a goto drop on error.

It seems like you are putting into message, then driver is putting
it into meta-data in next code block. Maybe it should be combined?