The following reply was made to PR kern/54977; it has been noted by GNATS.
From: "David H. Gutteridge" <david%gutteridge.ca@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc:
Subject: Re: kern/54977
Date: Sat, 19 Sep 2020 17:11:22 -0400
(Carrying over from PR kern/55671 -- I didn't know this was already
reported.) I don't know if it's of any use, but I captured a USB debug
log relating to this, at:
http://www.netbsd.org/~gutteridge/pen_drive_attach_failure.log
(As John D. Baker already noted here, this isn't an xhci(4)-specific
issue, it happens with other USB controllers as well.)