---
fixes:
  - |
    `bug 1882521`_ has now been resolved by increasing the incremental
    and max sleep times between device detach attempts. This works around some
    undefined QEMU behaviour documented in `bug 1894804`_ where overlapping
    ``device_del`` requests would cancel the initial call leading to a
    situation where the device was never detached fully.

    .. _bug 1882521: https://bugs.launchpad.net/nova/+bug/1882521
    .. _bug 1894804: https://bugs.launchpad.net/qemu/+bug/1894804
