Rx_crc_errors_phy errors seen during port going down

Infrastructure & Networking Software And Drivers SoC And SmartNIC
1

I am using CX6 card and the details are as below, observing crc errors(rx_crc_errors_phy: 1243) when the remote peer port shutdown(means when remote peer shut down the corresponding port on cx6 card goes down and crc errors are seen on cx6 port without any traffic). These are errors are not seen with CX5 ports.
[PN] Part number: MCX623106AN-CDAT
[EC] Engineering changes: AA
[V2] Vendor specific: MCX623106AN-CDAT
[SN] Serial number: MT2051T05016
Device Type: ConnectX6DX
Part Number: MCX623106AN-CDA_Ax
Description: ConnectX-6 Dx EN adapter card; 100GbE; Dual-port QSFP56; PCIe 4.0/3.0 x16;
PSID: MT_0000000359
PCI Device Name: 0000:21:00.0
Base GUID: b8cef603000a3cac
Base MAC: b8cef60a3cac
Versions: Current Available
FW 22.32.2004 N/A
PXE 3.6.0502 N/A
UEFI 14.25.0018 N/A

2

The firmware is too old please update firmware.

3

Hi @xiaofengl ,

Thanks for the support.
Upgraded to 22.40.1000, now crc errors are not seen but “rx_symbol_err_phy: 1258” still seen.
with 22.32.2004 version, both rx_crc_errors_phy/rx_symbol_err_phy are seen and both are equal. With latest FW only “symbol errors” seen

4

No need care about phy error. It will be corrected by FEC/CRC etc.

For ETH NIC you just need care packet drop and packet out of buffer counter.

5

Hi @xiaofengl,

I’m not sure I understand.
What is the difference of rx_crc_errors_phy and rx_symbol_err_phy?
We were seeing the same count in both counters.
And I don’t think it is correct count.

Are we fetching the count from rx_crc_errors_phy, not from rx_symbol_err_phy?

“No need care about phy error.”
→
Does this mean we don’t need to care about both rx_crc_errors_phy and rx_symbol_err_phy?
Then how do we detect CRC errors in Mellanox NIC?

6

There are serval phase PHY layer correct data, eg, FEC-PCS-CRC etc. You don’t need care that. It should not effect package unless packet drop.

The will be different symbol PAM4, FS4, etc with different correction method.

I don’t think you need understand these. unless you want to be expert of digital signal processing.