Re: [PATCH net-next 1/2] ravb: Add Rx checksum offload support

[Jakub Kicinski <kuba@kernel.org>]

On Tue, 23 Jan 2024 15:19:23 +0000 Biju Das wrote:
> +static void ravb_rx_csum_gbeth(struct sk_buff *skb)
> +{
> +	__sum16 csum_ip_hdr, csum_proto;
> +	u8 *hw_csum;
> +
> +	/* The hardware checksum status is contained in sizeof(__sum16) * 2 = 4
> +	 * bytes appended to packet data. First 2 bytes is ip header csum and
> +	 * last 2 bytes is protocol csum.
> +	 */
> +	if (unlikely(skb->len < sizeof(__sum16) * 2))
> +		return;
> +
> +	hw_csum = skb_tail_pointer(skb) - sizeof(__sum16);
> +	csum_proto = csum_unfold((__force __sum16)get_unaligned_le16(hw_csum));
> +
> +	hw_csum -= sizeof(__sum16);
> +	csum_ip_hdr = csum_unfold((__force __sum16)get_unaligned_le16(hw_csum));
> +	skb_trim(skb, skb->len - 2 * sizeof(__sum16));
> +
> +	/* TODO: IPV6 Rx csum */
> +	if (skb->protocol == htons(ETH_P_IP) && csum_ip_hdr == TOE_RX_CSUM_OK &&
> +	    csum_proto == TOE_RX_CSUM_OK)
> +		/* Hardware validated our checksum */
> +		skb->ip_summed = CHECKSUM_UNNECESSARY;
> +}

sparse does not seem to be onboard:

drivers/net/ethernet/renesas/ravb_main.c:771:20: warning: incorrect type in assignment (different base types)
drivers/net/ethernet/renesas/ravb_main.c:771:20:    expected restricted __sum16 [usertype] csum_proto
drivers/net/ethernet/renesas/ravb_main.c:771:20:    got restricted __wsum
drivers/net/ethernet/renesas/ravb_main.c:774:21: warning: incorrect type in assignment (different base types)
drivers/net/ethernet/renesas/ravb_main.c:774:21:    expected restricted __sum16 [usertype] csum_ip_hdr
drivers/net/ethernet/renesas/ravb_main.c:774:21:    got restricted __wsum
-- 
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