[Ethernet Issue] Feedback on the Dell Latitude 5420 (202010-28335)

Hello,

Having issues to make this laptop's ethernet interface work properly under Debian/Ubuntu. Ethernet speed is really slow, doesn't even have a 1/10 part of what should be expected.

I'm attaching outputs from Ubuntu 20.4LTS 5.8 kernel. If you need I can give you the same outputs but running on Debian 10 5.10 kernel.

I have tested same machine under Windows 10, no issues and ethernet speed is as expected.

$ ethtool -S enp0s31f6
NIC statistics:
     rx_packets: 29563
     tx_packets: 42223
     rx_bytes: 8077172
     tx_bytes: 52490426
     rx_broadcast: 5
     tx_broadcast: 13
     rx_multicast: 35
     tx_multicast: 192
     rx_errors: 266
     tx_errors: 0
     tx_dropped: 0
     multicast: 35
     collisions: 0
     rx_length_errors: 0
     rx_over_errors: 0
     rx_crc_errors: 133
     rx_frame_errors: 0
     rx_no_buffer_count: 0
     rx_missed_errors: 0
     tx_aborted_errors: 0
     tx_carrier_errors: 0
     tx_fifo_errors: 0
     tx_heartbeat_errors: 0
     tx_window_errors: 0
     tx_abort_late_coll: 0
     tx_deferred_ok: 0
     tx_single_coll_ok: 0
     tx_multi_coll_ok: 0
     tx_timeout_count: 0
     tx_restart_queue: 0
     rx_long_length_errors: 0
     rx_short_length_errors: 0
     rx_align_errors: 0
     tx_tcp_seg_good: 13861
     tx_tcp_seg_failed: 0
     rx_flow_control_xon: 0
     rx_flow_control_xoff: 0
     tx_flow_control_xon: 0
     tx_flow_control_xoff: 0
     rx_csum_offload_good: 29504
     rx_csum_offload_errors: 0
     rx_header_split: 0
     alloc_rx_buff_failed: 0
     tx_smbus: 0
     rx_smbus: 0
     dropped_smbus: 0
     rx_dma_failed: 0
     tx_dma_failed: 0
     rx_hwtstamp_cleared: 0
     uncorr_ecc_errors: 0
     corr_ecc_errors: 0
     tx_hwtstamp_timeouts: 0
     tx_hwtstamp_skipped: 0

$ sudo ethtool -i enp0s31f6
driver: e1000e
version: 3.2.6-k
firmware-version: 0.8-4
expansion-rom-version:
bus-info: 0000:00:1f.6
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: yes

$ sudo modinfo e1000e
filename: /lib/modules/5.8.0-48-generic/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko
version: 3.2.6-k
license: GPL v2
description: Intel(R) PRO/1000 Network Driver
author: Intel Corporation, <email address hidden>
srcversion: 5726DDD18033D5B33BE5693
alias: pci:v00008086d00001A1Dsv*sd*bc*sc*i*
alias: pci:v00008086d00001A1Csv*sd*bc*sc*i*
alias: pci:v00008086d00001A1Fsv*sd*bc*sc*i*
alias: pci:v00008086d00001A1Esv*sd*bc*sc*i*
alias: pci:v00008086d000015F5sv*sd*bc*sc*i*
alias: pci:v00008086d000015F4sv*sd*bc*sc*i*
alias: pci:v00008086d000015FAsv*sd*bc*sc*i*
alias: pci:v00008086d000015F9sv*sd*bc*sc*i*
alias: pci:v00008086d000015FCsv*sd*bc*sc*i*
alias: pci:v00008086d000015FBsv*sd*bc*sc*i*
alias: pci:v00008086d00000D55sv*sd*bc*sc*i*
alias: pci:v00008086d00000D53sv*sd*bc*sc*i*
alias: pci:v00008086d00000D4Dsv*sd*bc*sc*i*
alias: pci:v00008086d00000D4Csv*sd*bc*sc*i*
alias: pci:v00008086d00000D4Fsv*sd*bc*sc*i*
alias: pci:v00008086d00000D4Esv*sd*bc*sc*i*
alias: pci:v00008086d000015E2sv*sd*bc*sc*i*
alias: pci:v00008086d000015E1sv*sd*bc*sc*i*
alias: pci:v00008086d000015E0sv*sd*bc*sc*i*
alias: pci:v00008086d000015DFsv*sd*bc*sc*i*
alias: pci:v00008086d000015BCsv*sd*bc*sc*i*
alias: pci:v00008086d000015BBsv*sd*bc*sc*i*
alias: pci:v00008086d000015BEsv*sd*bc*sc*i*
alias: pci:v00008086d000015BDsv*sd*bc*sc*i*
alias: pci:v00008086d000015D6sv*sd*bc*sc*i*
alias: pci:v00008086d000015E3sv*sd*bc*sc*i*
alias: pci:v00008086d000015D8sv*sd*bc*sc*i*
alias: pci:v00008086d000015D7sv*sd*bc*sc*i*
alias: pci:v00008086d000015B9sv*sd*bc*sc*i*
alias: pci:v00008086d000015B8sv*sd*bc*sc*i*
alias: pci:v00008086d000015B7sv*sd*bc*sc*i*
alias: pci:v00008086d00001570sv*sd*bc*sc*i*
alias: pci:v00008086d0000156Fsv*sd*bc*sc*i*
alias: pci:v00008086d000015A3sv*sd*bc*sc*i*
alias: pci:v00008086d000015A2sv*sd*bc*sc*i*
alias: pci:v00008086d000015A1sv*sd*bc*sc*i*
alias: pci:v00008086d000015A0sv*sd*bc*sc*i*
alias: pci:v00008086d00001559sv*sd*bc*sc*i*
alias: pci:v00008086d0000155Asv*sd*bc*sc*i*
alias: pci:v00008086d0000153Bsv*sd*bc*sc*i*
alias: pci:v00008086d0000153Asv*sd*bc*sc*i*
alias: pci:v00008086d00001503sv*sd*bc*sc*i*
alias: pci:v00008086d00001502sv*sd*bc*sc*i*
alias: pci:v00008086d000010F0sv*sd*bc*sc*i*
alias: pci:v00008086d000010EFsv*sd*bc*sc*i*
alias: pci:v00008086d000010EBsv*sd*bc*sc*i*
alias: pci:v00008086d000010EAsv*sd*bc*sc*i*
alias: pci:v00008086d00001525sv*sd*bc*sc*i*
alias: pci:v00008086d000010DFsv*sd*bc*sc*i*
alias: pci:v00008086d000010DEsv*sd*bc*sc*i*
alias: pci:v00008086d000010CEsv*sd*bc*sc*i*
alias: pci:v00008086d000010CDsv*sd*bc*sc*i*
alias: pci:v00008086d000010CCsv*sd*bc*sc*i*
alias: pci:v00008086d000010CBsv*sd*bc*sc*i*
alias: pci:v00008086d000010F5sv*sd*bc*sc*i*
alias: pci:v00008086d000010BFsv*sd*bc*sc*i*
alias: pci:v00008086d000010E5sv*sd*bc*sc*i*
alias: pci:v00008086d0000294Csv*sd*bc*sc*i*
alias: pci:v00008086d000010BDsv*sd*bc*sc*i*
alias: pci:v00008086d000010C3sv*sd*bc*sc*i*
alias: pci:v00008086d000010C2sv*sd*bc*sc*i*
alias: pci:v00008086d000010C0sv*sd*bc*sc*i*
alias: pci:v00008086d00001501sv*sd*bc*sc*i*
alias: pci:v00008086d00001049sv*sd*bc*sc*i*
alias: pci:v00008086d0000104Dsv*sd*bc*sc*i*
alias: pci:v00008086d0000104Bsv*sd*bc*sc*i*
alias: pci:v00008086d0000104Asv*sd*bc*sc*i*
alias: pci:v00008086d000010C4sv*sd*bc*sc*i*
alias: pci:v00008086d000010C5sv*sd*bc*sc*i*
alias: pci:v00008086d0000104Csv*sd*bc*sc*i*
alias: pci:v00008086d000010BBsv*sd*bc*sc*i*
alias: pci:v00008086d00001098sv*sd*bc*sc*i*
alias: pci:v00008086d000010BAsv*sd*bc*sc*i*
alias: pci:v00008086d00001096sv*sd*bc*sc*i*
alias: pci:v00008086d0000150Csv*sd*bc*sc*i*
alias: pci:v00008086d000010F6sv*sd*bc*sc*i*
alias: pci:v00008086d000010D3sv*sd*bc*sc*i*
alias: pci:v00008086d0000109Asv*sd*bc*sc*i*
alias: pci:v00008086d0000108Csv*sd*bc*sc*i*
alias: pci:v00008086d0000108Bsv*sd*bc*sc*i*
alias: pci:v00008086d0000107Fsv*sd*bc*sc*i*
alias: pci:v00008086d0000107Esv*sd*bc*sc*i*
alias: pci:v00008086d0000107Dsv*sd*bc*sc*i*
alias: pci:v00008086d000010B9sv*sd*bc*sc*i*
alias: pci:v00008086d000010D5sv*sd*bc*sc*i*
alias: pci:v00008086d000010DAsv*sd*bc*sc*i*
alias: pci:v00008086d000010D9sv*sd*bc*sc*i*
alias: pci:v00008086d00001060sv*sd*bc*sc*i*
alias: pci:v00008086d000010A5sv*sd*bc*sc*i*
alias: pci:v00008086d000010BCsv*sd*bc*sc*i*
alias: pci:v00008086d000010A4sv*sd*bc*sc*i*
alias: pci:v00008086d0000105Fsv*sd*bc*sc*i*
alias: pci:v00008086d0000105Esv*sd*bc*sc*i*
depends:
retpoline: Y
intree: Y
name: e1000e
vermagic: 5.8.0-48-generic SMP mod_unload modversions
sig_id: PKCS#7
signer: Build time autogenerated kernel key
sig_key: 7D:53:30:D0:18:D9:2D:B9:CC:E1:AB:FB:83:7F:05:5A:4E:74:37:7E
sig_hashalgo: sha512
signature: A6:19:87:EA:35:36:89:F8:DE:6E:BF:80:F9:36:89:5D:32:20:E3:87:
  F3:A3:DD:86:34:41:07:A7:B1:F0:6F:B2:5B:96:9F:93:BB:0B:5D:18:
  A5:DF:26:1D:82:BE:3A:D7:E1:8F:F0:A4:8E:72:39:E7:92:0E:D4:C0:
  C1:C9:13:82:BD:12:39:01:4D:60:CE:6D:90:2F:D1:77:A0:E3:D2:85:
  9B:88:B9:33:DC:00:ED:95:30:CE:DA:76:68:6B:E5:1F:B3:7F:DB:90:
  19:BA:E0:11:01:9D:68:7D:10:8E:35:4C:37:70:4C:1B:72:70:E5:91:
  3A:15:3C:21:6F:22:8A:8D:A9:D3:70:6F:53:4F:9D:46:5E:0D:0B:A1:
  09:2A:B7:CA:32:43:40:E5:FA:0C:19:30:CC:FC:40:75:0B:62:3E:A4:
  0F:3E:9B:69:97:DB:75:6E:A1:F1:1A:EC:73:1C:1C:19:36:82:10:9F:
  9F:FB:E3:22:8E:F8:59:AA:A5:CD:AF:4F:4A:2C:D9:58:4A:3A:8E:E8:
  6E:88:F9:42:20:6B:A7:A0:28:7A:A7:81:AA:11:03:0E:FA:C4:DA:5A:
  9D:3F:AA:1C:7F:7E:C3:25:62:CB:36:49:70:E3:A7:73:A1:29:E9:E7:
  62:97:F1:83:07:B2:A6:13:F3:4C:28:43:8C:C4:49:2C:72:92:1C:2D:
  50:DE:AF:DB:1D:47:52:EA:B6:FD:21:41:13:8F:26:46:EB:2B:29:C6:
  A0:40:4E:CF:95:B3:CB:B0:5B:9A:AF:8A:6F:15:F7:89:31:F6:C5:BE:
  C9:9D:44:73:11:28:3E:84:8F:57:57:97:B9:28:D3:97:4B:BE:D0:48:
  25:2F:29:71:89:EB:B0:AD:A5:FB:67:67:4F:2E:AF:D9:F6:64:CB:22:
  42:54:10:87:61:61:D8:40:1C:BC:FB:C2:56:91:3F:54:D5:84:11:0A:
  10:96:17:2B:4C:17:6F:32:CB:2F:EE:C8:DE:FB:32:2C:72:32:1A:27:
  69:19:62:F4:8F:73:4D:02:97:1E:00:94:5F:1F:F6:01:15:29:5A:B4:
  F8:51:A3:F3:D8:DB:DF:D1:FD:15:D3:61:C2:46:AC:50:75:4F:56:E0:
  26:D6:E1:9C:58:AA:28:5F:60:09:67:E1:F9:97:62:76:80:AB:1A:67:
  2F:9B:97:51:E4:6E:69:CA:F0:58:2F:45:D1:85:6A:05:0D:9B:C9:14:
  7F:2F:EE:44:64:A2:4C:BD:60:0F:1D:D7:39:21:F6:27:9C:A9:CF:5F:
  0E:5A:E6:B3:8D:E9:F5:EB:22:76:55:02:E6:02:D4:95:A0:E1:EE:D9:
  EB:4E:8F:91:4F:CA:2B:5D:01:D9:E3:94
parm: debug:Debug level (0=none,...,16=all) (int)
parm: copybreak:Maximum size of packet that is copied to a new buffer on receive (uint)
parm: TxIntDelay:Transmit Interrupt Delay (array of int)
parm: TxAbsIntDelay:Transmit Absolute Interrupt Delay (array of int)
parm: RxIntDelay:Receive Interrupt Delay (array of int)
parm: RxAbsIntDelay:Receive Absolute Interrupt Delay (array of int)
parm: InterruptThrottleRate:Interrupt Throttling Rate (array of int)
parm: IntMode:Interrupt Mode (array of int)
parm: SmartPowerDownEnable:Enable PHY smart power down (array of int)
parm: KumeranLockLoss:Enable Kumeran lock loss workaround (array of int)
parm: WriteProtectNVM:Write-protect NVM [WARNING: disabling this can lead to corrupted NVM] (array of int)
parm: CrcStripping:Enable CRC Stripping, disable if your BMC needs the CRC (array of int)

$ lspci | grep -i ethernet
00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (13) I219-LM (rev 20)

You can see in the first ethtool output all the RX_CRC and RX errors from just 5 minutes of Ethernet traffic.

This model of Latitude is, supposedly, certified to work under Ubuntu (hence Debian) and that's one of the reasons I choosed it. I would greatly appreciate feedback from your end.

Thanks in advance.

Gerard.