From USB 2.0, section 9.4.5:
"For endpoints using data toggle, regardless of whether an endpoint has
the Halt feature set, a ClearFeature(ENDPOINT_HALT) request always
results in the data toggle being reinitialized to DATA0."
Linux issues a `GET_STATUS` request to validate that a USB device has
correctly resumed after an idle suspend; but HackRF has thus far not
implemented `GET_STATUS`. As a result, Linux assumes our USB devices
are failing to resume, and winds up resetting them. Oops. ^-^