augustss@netbsd.org writes:
> Synopsis: usb mct modem control lines get stuck
> 
> Do you still have this problem?

I've stopped using this MCT adaptor because it was never very
reliable.

Since other adaptors work just fine (eg. Prolific Technology PL2303
Serial, rev 1.10/2.02), I'm inclined to say it is a problem specific
to MCT.  Feel free to close the PR.

-wolfgang