kern/60629: eqos(4) problem with checksum offload?

["riz%tastylime.net@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60629
>Category:       kern
>Synopsis:       eqos(4) problem with checksum offload?
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Aug 22 00:40:00 +0000 2026
>Originator:     Jeff Rizzo
>Release:        11.99.7
>Organization:
>Environment:
NetBSD riscv64 11.99.7 NetBSD 11.99.7 (GENERIC64) #3: Sat Aug 22 00:16:37 UTC 2026  riz%acai.tastylime.net@localhost:/tank/netbsd/current/obj.riscv-riscv64/sys/arch/riscv/compile/GENERIC64 riscv
>Description:
When trying to ssh to certain hosts (looks like ones on my local LAN, but I'm not 100% sure), I was noticing errors on console:

[ 256.3266933] eqos0: TX [45] tx error: 0x10009000
[ 256.3266933] eqos0: TX [48] tx error: 0x10009000
[ 256.3266933] eqos0: TX [56] tx error: 0x10009000

...and the ssh wouldn't complete.  A little digging showed that that error looks related to checksum offload, so I disabled it with:

ifconfig eqos0 -tcp4csum-tx -udp4csum-tx -ip4csum-tx

...and all the hosts I was having ssh issues with magically started working.
>How-To-Repeat:
ssh from the visionfive 2 board I'm setting up to a host on my LAN
See tx errors on console and output errors via netstat:

         netstat -i -I eqos0
Name  Mtu   Network       Address              Ipkts Ierrs    Opkts Oerrs Colls
eqos0 1500  <Link>        6c:cf:39:00:af:d8     3708     1      819    20     0
eqos0 1500  fe80::/64     fe80::d395:465a:c     3708     1      819    20     0
eqos0 1500  10.187/16     10.187.3.237          3708     1      819    20     0
eqos0 1500  2001:5a8:4cf5 2001:5a8:4cf5:9b0     3708     1      819    20     0
eqos0 1500  fde3:ec59:ddd fde3:ec59:dddc:0:     3708     1      819    20     0
>Fix:
yes please.  I'm currently working around it by disabling tx checksum offloading.