Problem with USB serial in linux emulation

Morgan Wesström freebsd-questions at
Thu Jan 14 20:10:46 UTC 2010

Morgan Wesström wrote:
> Dear list.
> I have an USB smartcard reader that emulates a serial port. It uses the
> uftdi.ko kernel module and creates the following device nodes when
> plugged in. System is FreeBSD 7.2-RELEASE-p3 amd64.
> crw-rw----  1 uucp  dialer    0, 110 Jan 14 19:27 /dev/cuaU0
> crw-rw----  1 uucp  dialer    0, 111 Jan  7 14:01 /dev/cuaU0.init
> crw-rw----  1 uucp  dialer    0, 112 Jan  7 14:01 /dev/cuaU0.lock
> crw-------  1 root  wheel     0, 107 Jan 14 19:25 /dev/ttyU0
> crw-------  1 root  wheel     0, 108 Jan  7 14:01 /dev/ttyU0.init
> crw-------  1 root  wheel     0, 109 Jan  7 14:01 /dev/ttyU0.lock
> dmesg output:
> ucom0: <FTDI USB <-> Serial, class 0/0, rev 1.10/4.00, addr 2> on uhub5
> I'm trying to access it with a linux program and the program initializes
> and manages to read at least some basic info from the card but any
> further communication with the card results in the following message
> regardless of what device node I use:
> linux_sys_futex: unknown op 265
> Same software and reader works on a pure linux machine.
> Does anyone have any hints on what I can do to try to track this problem
> down? Some clarification on what the difference is between cuaU0 and
> ttyU0 would be appreciated too and which of them I should use primarily.

Adding some more info myself here. Initially I only copied the shared
libraries the program needed from my Linux computer and loaded the linux
kernel module. Installing the full linux_base-f10 port seems to get rid
of the error message so it seems unrelated to the actual communication
problem I experience.
The program initially detects the card in the reader but as soon as I
try to communicate with it, the program thinks the reader is empty. Does
anyone recognize this behaviour?

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