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Date: Wed, 09 Apr 2008 04:44:39 -0600 (MDT)
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To: jhein@timing.com
From: "M. Warner Losh" <imp@bsdimp.com>
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Cc: arch@freebsd.org, phk@phk.freebsd.dk
Subject: Re: tt_ioctl 
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In message: <18428.624.490619.248235@gromit.timing.com>
            John E Hein <jhein@timing.com> writes:
: You can't use ugen, for instance, for the dual ftdi chip where you
: want one port to be uart and the other to be jtag.  And you can't use
: it if you want to switch between ucom and ugen without rebooting
: (at least not in 6.x or 7.x).  As I said, I haven't figured out
: if that is by design or not.

It is possible with enough kernel hacking to make it happen.  This
particular misfeature is due to the really poor job that the usb code
does integrating with newbus.

Warner