I've been getting similar disconnects on a Dell Latitude 5580 that is connected to a Dell D6000 docking station via USB-C. I'm also using DisplayLink driver version 4.4.24 (https://www.displaylink.com/downloads/ubuntu) in order to connect to two external displays. With Ubuntu 17.10 I was not seeing any disconnects. With 18.04 I see at least one per day where the external monitors go dark, and these messages in syslog:
Nov 13 10:26:39 steveclx5580 kernel: usb 3-1: USB disconnect, device number 2 Nov 13 10:26:39 steveclx5580 kernel: usb 3-1.2: USB disconnect, device number 3 Nov 13 10:26:39 steveclx5580 kernel: usb 3-1.2.2: USB disconnect, device number 5 Nov 13 10:26:39 steveclx5580 kernel: xhci_hcd 0000:3d:00.0: xHCI host controller not responding, assume dead Nov 13 10:26:39 steveclx5580 kernel: xhci_hcd 0000:3d:00.0: HC died; cleaning up Nov 13 10:26:39 steveclx5580 kernel: usb 4-1: USB disconnect, device number 2 Nov 13 10:26:39 steveclx5580 kernel: usb 4-1.1: USB disconnect, device number 3 Nov 13 10:26:39 steveclx5580 kernel: cdc_ncm 4-1.1:1.5 enx9cebe8551508: unregister 'cdc_ncm' usb-0000:3d:00.0-1.1, CDC NCM Nov 13 10:26:39 steveclx5580 NetworkManager[1089]: <info> [1542122799.4322] device (enx9cebe8551508): state change: unavailable -> unmanaged (reason 'removed', sys-iface-state: 'removed') This morning I tried the linux-oem package based on comments in this bug report. $ uname -a Linux steveclx5580 4.15.0-1024-oem #29-Ubuntu SMP Tue Oct 16 08:14:23 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux I am still seeing disconnects, and they are more frequent than before: Nov 14 10:43:46 steveclx5580 kernel: usb 3-1: USB disconnect, device number 2 Nov 14 10:43:46 steveclx5580 kernel: usb 3-1.2: USB disconnect, device number 3 Nov 14 10:43:46 steveclx5580 kernel: usb 3-1.2.2: USB disconnect, device number 5 Nov 14 10:43:46 steveclx5580 kernel: xhci_hcd 0000:3d:00.0: xHCI host controller not responding, assume dead Nov 14 10:43:46 steveclx5580 kernel: xhci_hcd 0000:3d:00.0: HC died; cleaning up Nov 14 10:43:46 steveclx5580 kernel: usb 4-1: USB disconnect, device number 2 Nov 14 10:43:46 steveclx5580 kernel: usb 4-1.1: USB disconnect, device number 3 Nov 14 10:43:46 steveclx5580 kernel: cdc_ncm 4-1.1:1.5 enx9cebe8551508: unregister 'cdc_ncm' usb-0000:3d:00.0-1.1, CDC NCM Nov 14 10:43:46 steveclx5580 upowerd[2272]: unhandled action 'unbind' on /sys/devices/pci0000:00/0000:00:1c.4/0000:05:00.0/0000:06: 02.0/0000:3d:00.0/usb4/4-1/4-1.1/4-1.1:1.1 Nov 14 10:43:46 steveclx5580 upowerd[2272]: unhandled action 'unbind' on /sys/devices/pci0000:00/0000:00:1c.4/0000:05:00.0/0000:06: 02.0/0000:3d:00.0/usb4/4-1/4-1.1/4-1.1:1.0 Nov 14 10:43:46 steveclx5580 dhclient[3858]: receive_packet failed on enx9cebe8551508: Network is down I do regularly suspend/resume this laptop, but the latest disconnects have happened without a prior resume. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1763594 Title: xhci hangs; reset results in NULL pointer dereference To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/1763594/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
