Try to cancel operation and close devices on suspend
It appears that some fingerprint devices may remain powered up during suspend. In extreme cases, the state about ongoing operations can even survive and interfere with newly started operations after the resume.
Drivers should handle these errors gracefully and should really be capable of returning the device into a good state. But it seems like a good idea to also be smarter in fprintd already.
So, fprintd should grab a delay inhibitor for sleep. If sleep happens, it should cancel the ongoing operation and close the FpDevice. Doing so will also ensure that devices are in a low power state.