[PATCH v3 net-next 2/3] net: hns3/mls5e: fix CWR handling in drivers to preserve ACE signal
From: <hidden>
Date: 2026-02-03 16:11:41
Also in:
bpf, linux-doc, linux-kselftest, linux-rdma, virtualization
Subsystem:
hisilicon network subsystem 3 driver (hns3), hisilicon network subsystem driver, mellanox ethernet driver (mlx5e), mellanox mlx5 core vpi driver, networking drivers, the rest · Maintainers:
Jian Shen, Jijie Shao, Saeed Mahameed, Tariq Toukan, Mark Bloch, Leon Romanovsky, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Chia-Yu Chang <redacted> Currently, hns3 and mlx5 Rx paths use SKB_GSO_TCP_ECN flag when a TCP segment with the CWR flag set. This is wrong because SKB_GSO_TCP_ECN is only valid for RFC3168 ECN on Tx, and using it on Rx allows RFC3168 ECN offload to clear the CWR flag. As a result, incoming TCP segments lose their ACE signal integrity required for AccECN (RFC9768), especially when the packet is forwarded and later re-segmented by GSO. Fix this by setting SKB_GSO_TCP_ACCECN for any Rx segment with the CWR flag set. SKB_GSO_TCP_ACCECN ensure that RFC3168 ECN offload will not clear the CWR flag, therefore preserving the ACE signal. Signed-off-by: Chia-Yu Chang <redacted> --- v3: - Rewrite the commit message for clarity --- drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 2 +- drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index a47464a22751..3a1cf4335477 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c@@ -3897,7 +3897,7 @@ static int hns3_gro_complete(struct sk_buff *skb, u32 l234info) skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; if (th->cwr) - skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; + skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ACCECN; if (l234info & BIT(HNS3_RXD_GRO_FIXID_B)) skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_FIXEDID;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 1fc3720d2201..d174f83478a3 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c@@ -1311,7 +1311,7 @@ static void mlx5e_shampo_update_ipv4_tcp_hdr(struct mlx5e_rq *rq, struct iphdr * skb->csum_offset = offsetof(struct tcphdr, check); if (tcp->cwr) - skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; + skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ACCECN; } static void mlx5e_shampo_update_ipv6_tcp_hdr(struct mlx5e_rq *rq, struct ipv6hdr *ipv6,
@@ -1332,7 +1332,7 @@ static void mlx5e_shampo_update_ipv6_tcp_hdr(struct mlx5e_rq *rq, struct ipv6hdr skb->csum_offset = offsetof(struct tcphdr, check); if (tcp->cwr) - skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; + skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ACCECN; } static void mlx5e_shampo_update_hdr(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe, bool match)
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2.34.1