Re: RX CRC errors on I219-V (6) 8086:15be

[Kai-Heng Feng <kai.heng.feng@canonical.com>]

at 02:01, Bjorn Helgaas <helgaas@kernel.org> wrote:

> On Tue, Jul 02, 2019 at 04:25:59PM +0800, Kai Heng Feng wrote:
>> +linux-pci
>>
>> Hi Sasha,
>>
>> at 6:49 PM, Kai-Heng Feng <kai.heng.feng@canonical.com> wrote:
>>
>>> at 14:26, Neftin, Sasha <sasha.neftin@intel.com> wrote:
>>>
>>>> On 6/26/2019 09:14, Kai Heng Feng wrote:
>>>>> Hi Sasha
>>>>> at 5:09 PM, Kai-Heng Feng <kai.heng.feng@canonical.com> wrote:
>>>>>> Hi Jeffrey,
>>>>>>
>>>>>> We’ve encountered another issue, which causes multiple CRC
>>>>>> errors and renders ethernet completely useless, here’s the
>>>>>> network stats:
>>>>> I also tried ignore_ltr for this issue, seems like it alleviates
>>>>> the symptom a bit for a while, then the network still becomes
>>>>> useless after some usage.
>>>>> And yes, it’s also a Whiskey Lake platform. What’s the next step
>>>>> to debug this problem?
>>>>> Kai-Heng
>>>> CRC errors not related to the LTR. Please, try to disable the ME on
>>>> your platform. Hope you have this option in BIOS. Another way is to
>>>> contact your PC vendor and ask to provide NVM without ME. Let's
>>>> start debugging with these steps.
>>>
>>> According to ODM, the ME can be physically disabled by a jumper.
>>> But after disabling the ME the same issue can still be observed.
>>
>> We’ve found that this issue doesn’t happen to SATA SSD, it only happens  
>> when
>> NVMe SSD is in use.
>>
>> Here are the steps:
>> - Disable NVMe ASPM, issue persists
>> - modprobe -r e1000e && modprobe e1000e, issue doesn’t happen
>> - Enabling NVMe ASPM, issue doesn’t happen
>>
>> As long as NVMe ASPM gets enabled after e1000e gets loaded, the issue
>> doesn’t happen.
>
> IIUC the problem happens with the mainline and dev-queue e1000e
> driver, but not with the out-of-tree Intel driver.  Since there is a
> working driver and there's the potential (at least in principle) for
> unifying them or bisecting between them, I have limited interest in
> debugging it from scratch.

I wonder why disabling ASPM on a device solves another device’s issue?
The issue may just get papered over by the “working” driver. I’d like to  
understand the root cause behind this symptom.

>
> If it turns out to be a PCI core problem, I would want to know: What's
> the PCI topology?  "lspci -vv" output for the system?  Does it make a
> difference if you boot with "pcie_aspm=off"?  Collect complete dmesg,
> maybe attach it to a kernel.org bugzilla?

Parameter “pcie_aspm=off” doesn’t work for the system.
I need to use "pcie_aspm=force” and change the policy to “performance”.
The issue is gone once e1000e loads after ASPM is disabled, either globally  
or only disabling ASPM on NVMe.

Files attached to https://bugzilla.kernel.org/show_bug.cgi?id=204057

Kai-Heng

>
>>>>>> /sys/class/net/eno1/statistics$ grep . *
>>>>>> collisions:0
>>>>>> multicast:95
>>>>>> rx_bytes:1499851
>>>>>> rx_compressed:0
>>>>>> rx_crc_errors:1165
>>>>>> rx_dropped:0
>>>>>> rx_errors:2330
>>>>>> rx_fifo_errors:0
>>>>>> rx_frame_errors:0
>>>>>> rx_length_errors:0
>>>>>> rx_missed_errors:0
>>>>>> rx_nohandler:0
>>>>>> rx_over_errors:0
>>>>>> rx_packets:4789
>>>>>> tx_aborted_errors:0
>>>>>> tx_bytes:864312
>>>>>> tx_carrier_errors:0
>>>>>> tx_compressed:0
>>>>>> tx_dropped:0
>>>>>> tx_errors:0
>>>>>> tx_fifo_errors:0
>>>>>> tx_heartbeat_errors:0
>>>>>> tx_packets:7370
>>>>>> tx_window_errors:0
>>>>>>
>>>>>> Same behavior can be observed on both mainline kernel and on
>>>>>> your dev-queue branch.
>>>>>> OTOH, the same issue can’t be observed on out-of-tree e1000e.
>>>>>>
>>>>>> Is there any plan to close the gap between upstream and
>>>>>> out-of-tree version?
>>>>>>
>>>>>> Kai-Heng