produces user-visible errors and may confuse implementations. (E.g., when
probing for an unimplemented feature and subsequently being greeted by a
timeout.)
- fw/comon/usb.c (handle_setup): set SOPRDY when answering a request error
with a stall, according to the example in AN139. This seems to eliminate
the timeouts observed in requests following after bad requests.
- fw/boot/boot.c (run_payload): described how the host is expected to
respond to the device resetting its USB stack
