Re: USB2 problems with Fedora/USRP


I’ve finally assembled the USRP few days ago, after being delayed some months.

The power-on behaviour
looks as expected: one led blinks at 3 Hz or so.
The next step is to try out some example, e.g.
Whatever the test I try, I can see that blinking led is switched of for a couple seconds, then it
blinks at lower
rate, and another led near to it turns on (don’t remember which is D402 and D403).

On console,
i get this kind of error:

usb_control_msg failed: error sending control message: Connection timed out
failed to load fpga bitstream
Traceback (most recent call last):

File "./", line 106, in ?
    main ( )
File "./", line 96, 

in main

    ok=run_test (rate, verbose)
File "./", line 63, in run_test

usrp_tx=usrp.sink_s(0, tx_interp)

File "/usr/local/hamradio/gnuradio/lib/python2.5/site-packages/gnuradio/usrp.

py", line 230, in init

    fpga_filename, firmware_filename)

line 940, in sink_s



RuntimeError: can’t open usrp1

I’m using the latest svn checked-out source code.

almost convinced that the problem is in the USB2 driver used by gnuradio
to control the USRP (ehci-hcd?).
I have 2

  1. What do you suggest to use to investigate and troubleshoot such USB2 problem on Fedora 9?
  2. What
    does the second led turning on mean?

t.i.a. for help.

==== On Thu, 2009-01-15 at 13:57 -0800, Johnathan
Corgan wrote:

In my experience, a successful FX2 load followed by a failed FPGA load
is often due to poor USB
physical integrity, such as a cable, connector,
or hub. I know it sounds formulaic, but for whatever reason, I’ve

encountered this with the USRP on multiple occasions, where replacing

the cable with a different one, ensuring that
has the 2.0 compliance
logo on it, fixes it. YMMV, of course.

(Even more often it is due to not having a 2.0
controller, but you’ve
ruled that out already.)



Well, well, Johnathan, you were right.
found a solution to the problem - not yet an explanation, which requires
a USB guru to explain (anybody out there…?)

I actually plugged the USB cable to an external hub, which is not even
powered (and not even top-branded…) and the
problem does not show anymore.
Note that, after your suggestion, I have tried all four USB2 sockets
available on the
laptop and none worked.
Thus, in this instance, it seems that introducing a hub layer in the
path solves the problem.

Thanks again for help

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