I use ubuntu 18.04 with 4.15 kernel I have hit the same problem, but with synaptics touchpad.
I have bisected 4.13-4.14 and the problem was in commit 1455cf8dbfd06aa7651dcfccbadb7a093944ca65 (as in the attached patch) I am unable to use USB bus because udev is bogged down with these bind/unbind events ``` UDEV [496.168312] bind /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4.2/2-1.4.2:1.0 (usb) KERNEL[496.175932] bind /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4.2/2-1.4.2:1.0 (usb) KERNEL[496.176947] unbind /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4.2/2-1.4.2:1.0 (usb) UDEV [496.177602] unbind /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4.2/2-1.4.2:1.0 (usb) KERNEL[496.185259] bind /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4.2/2-1.4.2:1.0 (usb) KERNEL[496.185479] unbind /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4.2/2-1.4.2:1.0 (usb) UDEV [496.186342] bind /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4.2/2-1.4.2:1.0 (usb) KERNEL[496.196813] bind /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4.2/2-1.4.2:1.0 (usb) KERNEL[496.197103] unbind /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4.2/2-1.4.2:1.0 (usb) UDEV [496.197501] unbind /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4.2/2-1.4.2:1.0 (usb) KERNEL[496.207283] bind /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4.2/2-1.4.2:1.0 (usb) ``` ``` > cat /sys/bus/usb/devices/2-1.4/2-1.4.2/id* 8162 413c ``` ``` > lsusb -d 413c:8162 Bus 002 Device 006: ID 413c:8162 Dell Computer Corp. Integrated Touchpad [Synaptics] ``` -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1759836 Title: systemd-udevd consumes 100% of CPU To manage notifications about this bug go to: https://bugs.launchpad.net/kernel/+bug/1759836/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
