I'm running into a similar issue with an HP Zbook Studio G4 running Ubuntu 18.04, HP Thunderbolt 3 dock and an IOGEAR 3.0/4 Port Peripheral Sharing Switch (GUS434). Often shortly after I switch back to the HP using the USB switch I get the xHCI host controller not responding, assume dead message. Based on Oded's input above I created the following service to fix it for me:
/lib/systemd/system/xhci-watch.service ``` [Unit] Description=Restart xhci when it dies [Service] ExecStart=/path/to/restart-xhci.sh [Install] WantedBy=multi-user.target ``` script: ``` #!/bin/bash dmesg -l err -w -T | awk -F " " ' /xhci_hcd.*dead/ { system("sleep 1"); device=substr($7, 1, length($7)-1); cmd="echo -n \""device"\" | tee /sys/bus/pci/drivers/xhci_hcd/unbind"; system(cmd); system("sleep 1"); cmd="echo -n \""device"\" | tee /sys/bus/pci/drivers/xhci_hcd/bind"; system(cmd); notify="notify-send \"restarting "device" \" \""$0"\" -u critical -i face-worried"; system(notify); }' ``` obviously this is an ugly hack, but it might help some while a better fix is developed. My bash/awk skills are not the best, so please feel free to offer suggestions for improvement -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1766076 Title: USB over thunderbolt turns off every once in a while To manage notifications about this bug go to: https://bugs.launchpad.net/dell-sputnik/+bug/1766076/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs