[Bug 256296] "No Device" error after using asynchronous API of libusb once

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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=256296

            Bug ID: 256296
           Summary: "No Device" error after using asynchronous API of
                    libusb once
           Product: Base System
           Version: Unspecified
          Hardware: Any
                OS: Any
            Status: New
          Severity: Affects Some People
          Priority: ---
         Component: usb
          Assignee: usb at FreeBSD.org
          Reporter: sergii.dmytruk at 3mdeb.com

Background information
----------------------

fwupd project is using libgusb, which is a Glib wrapper for libusb.

libgusb uses asynchronous API of libusb with events handled in a separate
thread.

fwupd works with devices by opening them, performing operations and then
closing.

How the failure occurs
----------------------

fwupd closes a device before all events of the operation have been processed.
This means that when libusb10_handle_events_sub() eventually processes related
event, the device gets marked as gone (device_is_gone field). On all future
calls libusb_submit_transfer() fails with LIBUSB_ERROR_NO_DEVICE because that
flag is set.

Effectively this means that a device can be used only once in such a way.

As I understand libgusb uses the API as intended and it is implementation of
libusb which shouldn't prevent repeated use of a device. Maybe it should wait
before closing or just reset the flag on opening the device.

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