As requested on the linux-usb mailing list, I've bisected the problem in the mainline git repository.
638139eb95d2d241781330a321e88c8dafe46078 is the first bad commit commit 638139eb95d2d241781330a321e88c8dafe46078 Author: Petr Mladek <[email protected]> Date: Fri Sep 19 17:32:24 2014 +0200 usb: hub: allow to process more usb hub events in parallel It seems that only choose_devnum() was not ready to process more hub events at the same time. All should be fine if we take bus->usb_address0_mutex there. It will make sure that more devnums will not be chosen for the given bus and the related devices at the same time. Signed-off-by: Petr Mladek <[email protected]> Acked-by: Alan Stern <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> :040000 040000 6c3b464b8db2bec572cf7904c0aac317b41c1eec da3ee40957d0637f17895ae05aad4a6646377b2a M drivers -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1485057 Title: "lsusb -v" as root freezes the kernel on Acer ES1-111 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1485057/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
