Network Cable Unplugged After waking from suspension after Upgrading to 21.04

I've just upgraded to 21.04. Now after waking from suspension. The network cable is shown as unplugged. I found a solution. which is I have to remove and reinstall the ethernet device driver. Via modprobe -r and then -i. Everytime after waking from suspend.

Is there any elegant and simple solution to fix this?

Upgraded from 20.10 to 21.04

lspci -nn | grep -i ethernet

04:00.0 Ethernet controller [0200]: Qualcomm Atheros Killer E220x Gigabit Ethernet Controller [1969:e091] (rev 13)


sudo lshw -C network
  *-network                 
       description: Ethernet interface
       product: Killer E220x Gigabit Ethernet Controller
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:04:00.0
       logical name: enp4s0
       version: 13
       serial: 44:8a:5b:46:f3:a5
       size: 1Gbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm pciexpress msi msix bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=alx driverversion=5.11.0-18-generic duplex=full ip=192.168.1.158 latency=0 link=yes multicast=yes port=twisted pair speed=1Gbit/s
       resources: irq:19 memory:f7900000-f793ffff ioport:d000(size=128)
  *-network DISABLED
       description: Wireless interface
       product: Wireless 3160
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:05:00.0
       logical name: wlp5s0
       version: 83
       serial: 30:3a:64:5f:7b:1b
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlwifi driverversion=5.11.0-18-generic firmware=17.3216344376.0 3160-17.ucode latency=0 link=no multicast=yes wireless=IEEE 802.11
       resources: irq:35 memory:f7800000-f7801fff



inxi -Fxz
System:    Kernel: 5.11.0-18-generic x86_64 bits: 64 compiler: gcc v: 10.2.1 Desktop: GNOME 3.38.4 
           Distro: Ubuntu 21.04 (Hirsute Hippo) 
Machine:   Type: Laptop System: Micro-Star product: GP70 2PE v: REV:1.0 serial: <filter> 
           Mobo: Micro-Star model: MS-175A v: REV:1.0 serial: <filter> BIOS: American Megatrends v: E175AIMS.109 
           date: 05/27/2014 
Battery:   ID-1: BAT1 charge: 6.8 Wh condition: 6.8/48.8 Wh (14%) model: MSI Corp. MS-175A status: Full 
CPU:       Info: Quad Core model: Intel Core i7-4710HQ bits: 64 type: MT MCP arch: Haswell rev: 3 L2 cache: 6 MiB 
           flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 39909 
           Speed: 2561 MHz min/max: 1800/3500 MHz Core speeds (MHz): 1: 2561 2: 2852 3: 2695 4: 2582 5: 2495 6: 2494 7: 2467 
           8: 2487 
Graphics:  Device-1: Intel 4th Gen Core Processor Integrated Graphics vendor: Micro-Star MSI driver: i915 v: kernel 
           bus ID: 00:02.0 
           Device-2: NVIDIA GM108M [GeForce 840M] vendor: Micro-Star MSI driver: nvidia v: 460.80 bus ID: 01:00.0 
           Display: x11 server: X.Org 1.20.11 driver: loaded: modesetting,nvidia unloaded: fbdev,nouveau,vesa 
           resolution: 1600x900 
           OpenGL: renderer: GeForce 840M/PCIe/SSE2 v: 4.6.0 NVIDIA 460.80 direct render: Yes 
Audio:     Device-1: Intel Xeon E3-1200 v3/4th Gen Core Processor HD Audio vendor: Micro-Star MSI driver: snd_hda_intel 
           v: kernel bus ID: 00:03.0 
           Device-2: Intel 8 Series/C220 Series High Definition Audio vendor: Micro-Star MSI driver: snd_hda_intel v: kernel 
           bus ID: 00:1b.0 
           Sound Server: ALSA v: k5.11.0-18-generic 
Network:   Device-1: Qualcomm Atheros Killer E220x Gigabit Ethernet vendor: Micro-Star MSI driver: alx v: kernel port: d000 
           bus ID: 04:00.0 
           IF: enp4s0 state: up speed: 1000 Mbps duplex: full mac: <filter> 
           Device-2: Intel Wireless 3160 driver: iwlwifi v: kernel port: d000 bus ID: 05:00.0 
           IF: wlp5s0 state: down mac: <filter> 
Bluetooth: Device-1: Intel Bluetooth wireless interface type: USB driver: btusb v: 0.8 bus ID: 1-1.3:4 
           Report: ID: hci0 state: up running pscan bt-v: 2.1 lmp-v: 4.0 address: <filter> 
Drives:    Local Storage: total: 931.51 GiB used: 596.27 GiB (64.0%) 
           ID-1: /dev/sda vendor: Toshiba model: MQ01ABD100 size: 931.51 GiB temp: 39 C 
Partition: ID-1: / size: 914.9 GiB used: 596.27 GiB (65.2%) fs: ext4 dev: /dev/sda4 
           ID-2: /boot/efi size: 512 MiB used: 4 KiB (0.0%) fs: vfat dev: /dev/sda3 
Swap:      ID-1: swap-1 type: file size: 2 GiB used: 23.8 MiB (1.2%) file: /swapfile 
Sensors:   System Temperatures: cpu: 84.0 C mobo: N/A gpu: nvidia temp: 42 C 
           Fan Speeds (RPM): N/A 
Info:      Processes: 365 Uptime: 7h 58m Memory: 15.55 GiB used: 5.48 GiB (35.2%) Init: systemd runlevel: 5 Compilers: 
           gcc: 10.3.0 Packages: 2784 Shell: Bash v: 5.1.4 inxi: 3.3.01 

 cat /etc/network/interfaces and cat /etc/netplan/*.yaml
cat: /etc/network/interfaces: No such file or directory
cat: and: No such file or directory
cat: cat: No such file or directory
# Let NetworkManager manage all devices on this system
network:
  version: 2
  renderer: NetworkManager

Update. I followed the suggestions here. The drivers are not automatically removed and installed after waking from suspension. https://askubuntu.com/a/1058760/1247412

I think a reboot is too heavy and uneeded. Simply reload network card kernel modules can rejuvenate that dead network card.

In recent time i have same problems with my network card to go up from sleep to ram. But in the past i am 100% sure i has no problems. I suspect is the new kernel drivers, 5.11.0-25-generic, to blame here

So in Ubuntu 20.04 with lshw -C network i get the driver name, then with modprobe -rv driver_name will remove and with modprobe -v driver_name my cable ethernet network is back

Nothing else work, systemctl restart NetworkManager cant wake up my ethernet card without modprobe driver recicle step. I suspect is that WOL thing the culprit i mean they are waiting for a lan wake up not a local resume from sleep

aug 27 01:54:53 berbecel NetworkManager[2357602]: <info>  [1630018493.3313] manager: sleep: sleep requested (sleeping: no  enabled: yes)
aug 27 01:54:53 berbecel NetworkManager[2357602]: <info>  [1630018493.3314] manager: NetworkManager state is now ASLEEP
aug 27 01:54:53 berbecel NetworkManager[2357602]: <info>  [1630018493.3317] device (enp2s0): state change: activated -> deactivating (reason 'sleeping', sys-iface-state: 'managed')
aug 27 01:54:53 berbecel NetworkManager[2357602]: <info>  [1630018493.3692] device (enp2s0): state change: deactivating -> disconnected (reason 'sleeping', sys-iface-state: 'managed')
aug 27 01:54:53 berbecel NetworkManager[2357602]: <info>  [1630018493.3881] dhcp4 (enp2s0): canceled DHCP transaction
aug 27 01:54:53 berbecel NetworkManager[2357602]: <info>  [1630018493.3881] dhcp4 (enp2s0): state changed bound -> done
aug 27 01:54:53 berbecel NetworkManager[2357602]: <info>  [1630018493.3920] device (enp2s0): state change: disconnected -> unmanaged (reason 'sleeping', sys-iface-state: 'managed')
aug 28 02:24:11 berbecel NetworkManager[2357602]: <info>  [1630106651.3796] manager: sleep: wake requested (sleeping: yes  enabled: yes)
aug 28 02:24:11 berbecel NetworkManager[2357602]: <info>  [1630106651.3797] device (enp2s0): state change: unmanaged -> unavailable (reason 'managed', sys-iface-state: 'managed')
aug 28 02:24:11 berbecel NetworkManager[2357602]: <info>  [1630106651.3812] manager: NetworkManager state is now DISCONNECTED

but then

aug 28 02:47:59 berbecel NetworkManager[2368981]: <info>  [1630108079.2431] device (enp2s0): driver '(null)' does not support carrier detection.
aug 28 02:47:59 berbecel NetworkManager[2368981]: <info>  [1630108079.2433] device (enp2s0): driver 'alx' does not support carrier detection.
aug 28 02:47:59 berbecel NetworkManager[2368981]: <info>  [1630108079.2436] manager: (enp2s0): new Ethernet device (/org/freedesktop/NetworkManager/Devices/2)
aug 28 02:47:59 berbecel NetworkManager[2368981]: <info>  [1630108079.2445] device (enp2s0): state change: unmanaged -> unavailable (reason 'managed', sys-iface-state: 'external')
aug 28 02:47:59 berbecel NetworkManager[2368981]: <info>  [1630108079.2565] device (enp2s0): state change: unavailable -> disconnected (reason 'none', sys-iface-state: 'managed')
aug 28 02:47:59 berbecel NetworkManager[2368981]: <info>  [1630108079.2577] device (enp2s0): Activation: starting connection 'rdslink' (7ef38c4e-886b-3738-b740-eb3b676cde2d)
aug 28 02:47:59 berbecel NetworkManager[2368981]: <info>  [1630108079.2578] device (enp2s0): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
aug 28 02:47:59 berbecel NetworkManager[2368981]: <info>  [1630108079.2586] device (enp2s0): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
aug 28 02:47:59 berbecel NetworkManager[2368981]: <info>  [1630108079.2592] device (enp2s0): state change: config -> failed (reason 'config-failed', sys-iface-state: 'managed')
aug 28 02:47:59 berbecel NetworkManager[2368981]: <warn>  [1630108079.2606] device (enp2s0): Activation: failed for connection 'rdslink'

so look like device (enp2s0): driver 'alx' does not support carrier detection. means my QCA8171 Gigabit Ethernet has no WOL suport and going to sleep means will sleep forewer waiting for a WOl signal who will never arrive?

Try this... in terminal do nm-connection-editor and select your Wired Connection to edit.

• confirm Device ethernet address
• confirm WOL
• change Link Negotiation to Automatic
  • or try Manual/1000Mb/full
• reboot and retest

Also verify Connect automatically...

Update #1:

See bug report https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1931301

Update #2:

Used workaround fixes from Ubuntu 18.04 - Ethernet disconnected after suspend

I had the same issue with upgrade from 20.08 to 21.04, used wireless for a bit and today reinstalled 21.04 from scratch assuming it was some upgrading bug.

Fresh Install still fails the same way.

mike@mike-XPS-8930:~$ lspci -nn | grep -i ethernet 04:00.0 Ethernet controller [0200]: Qualcomm Atheros Killer E2400 Gigabit Ethernet Controller [1969:e0a1] (rev 10) mike@mike-XPS-8930:~$