From: Matt Fleming Commit 905d1a220e8d ("ice: Add E830 checksum offload support") added Generic Checksum (GCS) support for E830 NICs but omitted the 1's complement negation (~) when converting the hardware raw_csum to skb->csum for CHECKSUM_COMPLETE. Without the negation, every CHECKSUM_COMPLETE packet fails the fast-path validation in nf_ip_checksum() and falls through to software checksumming via __skb_checksum_complete(), which triggers the rate-limited "hw csum failure" warning. Packets are still accepted (the software recheck passes) but hardware checksum offload is effectively disabled and the warning floods dmesg on systems running nf_conntrack on VLAN sub-interfaces. Multiple other drivers (idpf, ehea, iwlwifi, cassini, sunhme, enetc) also apply ~ for CHECKSUM_COMPLETE. The ice driver was the only in-tree user of csum_unfold() for CHECKSUM_COMPLETE that omitted it. Fixes: 905d1a220e8d ("ice: Add E830 checksum offload support") Cc: stable@vger.kernel.org Reviewed-by: Aleksandr Loktionov Reviewed-by: Simon Horman Signed-off-by: Matt Fleming --- v2: - Add Cc: stable@vger.kernel.org (Aleksandr) - Pick up Reviewed-by tags from Aleksandr and Simon - No code changes v1: https://lore.kernel.org/netdev/20260408190214.1287708-1-matt@readmodwrite.com/ drivers/net/ethernet/intel/ice/ice_txrx_lib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c index e695a664e53d..c177579e0114 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c +++ b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c @@ -92,7 +92,7 @@ static void ice_rx_gcs(struct sk_buff *skb, desc = (struct ice_32b_rx_flex_desc_nic *)rx_desc; skb->ip_summed = CHECKSUM_COMPLETE; csum = (__force u16)desc->raw_csum; - skb->csum = csum_unfold((__force __sum16)swab16(csum)); + skb->csum = csum_unfold((__force __sum16)~swab16(csum)); } /** -- 2.43.0