Comment 0 for bug 1799393

== Comment: #0 - Michael Ranweiler - 2018-10-18 11:34:40 ==

---Problem Description---
At the system if u do
ethtool -S enP48p1s0f0 | grep wqe_err
     rx_wqe_err: 1
     rx0_wqe_err: 0
     rx1_wqe_err: 0
     rx2_wqe_err: 0
     rx3_wqe_err: 1
     rx4_wqe_err: 0
     rx5_wqe_err: 0
     rx6_wqe_err: 0
     rx7_wqe_err: 0
     rx8_wqe_err: 0
     rx9_wqe_err: 0
     rx10_wqe_err: 0
     rx11_wqe_err: 0
     rx12_wqe_err: 0
     rx13_wqe_err: 0
     rx14_wqe_err: 0
     rx15_wqe_err: 0

Will see that rx side is hitting issue.

---Additional Hardware Info---
Mellanox CX5 Ethernet 100G
lspci
0030:01:00.0 Ethernet controller: Mellanox Technologies MT28800 Family [ConnectX-5 Ex]
0030:01:00.1 Ethernet controller: Mellanox Technologies MT28800 Family [ConnectX-5 Ex]

Machine Type = P9

---Debugger---
A debugger is not configured

---Steps to Reproduce---
Using a CX5 Ethernet 100G card
lspci
0030:01:00.0 Ethernet controller: Mellanox Technologies MT28800 Family [ConnectX-5 Ex]
0030:01:00.1 Ethernet controller: Mellanox Technologies MT28800 Family [ConnectX-5 Ex]

just configure IP
ifconfig enP48p1s0f0 33.33.33.33 netmask 255.255.255.0 up
then partner system configure IP and then try ping -f
ping -f 33.33.33.33
PING 33.33.33.33 (33.33.33.33) 56(84) bytes of data.
........................................^C
--- 33.33.33.33 ping statistics ---
5413 packets transmitted, 5373 received, 0% packet loss, time 934ms
rtt min/avg/max/mdev = 0.015/0.019/0.669/0.010 ms, ipg/ewma 0.172/0.020 ms
# ping 33.33.33.33
PING 33.33.33.33 (33.33.33.33) 56(84) bytes of data.
^C
--- 33.33.33.33 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 1071ms

then at the recv system then do
ethtool -S enP48p1s0f0 | grep wqe_err
     rx_wqe_err: 1
     rx0_wqe_err: 0
     rx1_wqe_err: 0
     rx2_wqe_err: 0
     rx3_wqe_err: 1
     rx4_wqe_err: 0
     rx5_wqe_err: 0
     rx6_wqe_err: 0
     rx7_wqe_err: 0
     rx8_wqe_err: 0
     rx9_wqe_err: 0
     rx10_wqe_err: 0
     rx11_wqe_err: 0
     rx12_wqe_err: 0
     rx13_wqe_err: 0
     rx14_wqe_err: 0
     rx15_wqe_err: 0
you will see rx_wqe_err with a counter non-zero.

This is fixed by this patch:
https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/commit/?id=37fdffb217a45609edccbb8b407d031143f551c0

== Comment: #1 - Carol L. Soto - 2018-10-18 11:46:00 ==
I did a git clone to the cosmic tree and loaded the kernel in a system.

kernel 4.18.12 and I can recreate it.

lspci | grep Mell | grep ConnectX-5
0000:01:00.0 Ethernet controller: Mellanox Technologies MT28800 Family [ConnectX-5 Ex]
0000:01:00.1 Ethernet controller: Mellanox Technologies MT28800 Family [ConnectX-5 Ex]
0030:01:00.0 Infiniband controller: Mellanox Technologies MT28800 Family [ConnectX-5 Ex]
0030:01:00.1 Infiniband controller: Mellanox Technologies MT28800 Family [ConnectX-5 Ex]
:~# ethtool -S enp1s0f0 | grep wqe_err
     rx_wqe_err: 2
     rx0_wqe_err: 1
     rx1_wqe_err: 1
     rx2_wqe_err: 0
     rx3_wqe_err: 0
     rx4_wqe_err: 0
     rx5_wqe_err: 0
     rx6_wqe_err: 0
     rx7_wqe_err: 0
     rx8_wqe_err: 0
     rx9_wqe_err: 0
     rx10_wqe_err: 0
...

Let me check if the proposed patch needs backport or not.

== Comment: #3 - Carol L. Soto - 2018-10-18 13:34:46 ==
I was able to apply the proposed patch as it to the cosmic git tree and no issue. (no need to backport)
using a kernel 4.18.12+.

With the proposed patch I do not see wqe err and ping does not stop.
ethtool -S enp1s0f0 | grep wqe_err
     rx_wqe_err: 0
     rx0_wqe_err: 0
     rx1_wqe_err: 0
     rx2_wqe_err: 0
     rx3_wqe_err: 0
     rx4_wqe_err: 0
     rx5_wqe_err: 0
     rx6_wqe_err: 0
     rx7_wqe_err: 0
     rx8_wqe_err: 0
     rx9_wqe_err: 0
     rx10_wqe_err: 0
...