> -----Original Message----- > From: Jijie Shao <[email protected]> > Sent: Tuesday, August 11, 2026 3:32 PM > To: Chia-Yu Chang (Nokia) <[email protected]>; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; Koen De Schepper (Nokia) > <[email protected]>; [email protected]; > [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected] > Cc: [email protected] > Subject: Re: [PATCH v5 net-next 2/2] net: hns3: fix GSO_ECN flag setting in > the RX path > > > on 2026/8/5 5:35, [email protected] wrote: > > From: Chia-Yu Chang <[email protected]> > > > > Currently, the hns3 Rx path sets the SKB_GSO_TCP_ECN flag when a TCP > > segment with the CWR flag set is received. This is incorrect because > > the hns3 hardware GRO resets the IP ToS byte to 0 during packet > > aggregation. Consequently, no valid ECN signals are carreid, meaning > > that it cannot support RFC3168 ECN or Accurate ECN protocols. Setting > > SKB_GSO_TCP_ECN or SKB_GSO_TCP_ACCECN under these conditions misleads > > the upper network stack. > > > > Fix this by removing the incorrect SKB_GSO_TCP_ECN flag assignment in > > hns3_gro_complete(). > > > Tested on hns3 HW (2x 100G, direct cable, openEuler 24.03, kernel 7.2.0-rc6). > > tcpdump confirms HW GRO zeroes IP ToS: aggregated (>MTU) packets carry tos > 0x0, while non-aggregated packets keep their ToS/ECN marks — so the zeroing > is done by HW GRO, not the sender. Before patch, CWR packets had > SKB_GSO_TCP_ECN set (0x5 = SKB_GSO_TCPV4 | SKB_GSO_TCP_ECN). After patch, all > GRO events gso_type=0x1 (SKB_GSO_TCPV4 only), no 0x5 observed. > > Tested-by: Jijie Shao <[email protected]>
Thanks Jijie for confirmation, I will submit to net in the next round.
