Instability seen with some Fomu with v2.0.3

[tcal-x]

With some (not all, maybe about 50%) of Fomu I've used, I see the following symptom when release v2.0.3 foboot has been installed, some but not all of the time:

$ dfu-util -l
dfu-util 0.9

Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2019 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to http://sourceforge.net/p/dfu-util/tickets/

Failed to retrieve string descriptor 2
Found DFU: [1209:5bf0] ver=0101, devnum=86, cfg=1, intf=0, path="1-2.2", alt=0, name="UNKNOWN", serial="UNKNOWN"

The last line should be

Found DFU: [1209:5bf0] ver=0101, devnum=86, cfg=1, intf=0, path="1-2.2", alt=0, name="Fomu PVT running DFU Bootloader v2.0.3", serial="UNKNOWN"

Also, sometimes there is a noticeable pause before the reply comes back for dfu-util -l.

The good news: I have only observed this with v2.0.3. With v2.0.2, I see dependable behavior always returning the correct "name" string. Also, with recent head of master (and with my change back to 8b csr bus), it also works dependably.