Hello, Recently we experienced some issues with intel NIC (I219-LM and I219-V). It seems that after a wire reconnection, auto-negotation "fails" and link speed drips to 10 Mbps.
>From kernel logs: [17616.346150] e1000e: enp0s31f6 NIC Link is Down [17627.003322] e1000e: enp0s31f6 NIC Link is Up 10 Mbps Full Duplex, Flow Control: None [17627.003325] e1000e 0000:00:1f.6 enp0s31f6: 10/100 speed: disabling TSO $ethtool enp0s31f6 Settings for enp0s31f6: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supported pause frame use: No Supports auto-negotiation: Yes Supported FEC modes: Not reported Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Advertised pause frame use: No Advertised auto-negotiation: Yes Advertised FEC modes: Not reported Speed: 10Mb/s Duplex: Full Port: Twisted Pair PHYAD: 1 Transceiver: internal Auto-negotiation: on MDI-X: on (auto) Supports Wake-on: pumbg Wake-on: g Current message level: 0x00000007 (7) drv probe link Link detected: yes Notice that if disconnection last less than about 5 seconds, nothing wrong happens. And if after last failure, disconnection / connection occurs again and last less than 5 seconds, link speed is back to 1000 Mbps. [18075.350678] e1000e: enp0s31f6 NIC Link is Down [18078.716245] e1000e: enp0s31f6 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: None The following patch seems to fix this issue. However I don't clearly understand why. diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index 3ba0c90e7055..763c013960f1 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -5069,7 +5069,7 @@ static bool e1000e_has_link(struct e1000_adapter *adapter) case e1000_media_type_copper: if (hw->mac.get_link_status) { ret_val = hw->mac.ops.check_for_link(hw); - link_active = !hw->mac.get_link_status; + link_active = false; } else { link_active = true; } Maybe this is related to watchdog task. I've found out this fix by comparing with last commit that works fine : commit 0b76aae741abb9d16d2c0e67f8b1e766576f897d. However I don't know if this information is relevant. Thank you. Camille Bordignon