Thomas,

Thanks for the reply.  So I researched it some more, both with Python and C
programs which give the same response.  I have posted my Python script here
http://pastebin.com/k7PuLsQq and for the C program I just used the
libftdispi at http://code.google.com/p/libftdispi/ and I have several things
that I would like to point out:

1. If I only try to claim INTERFACE_A, then I get usb_bulk_write fails (no
new message shown with dmesg) and program execution does not complete.
2. If I try to claim other interfaces besides INTERFACE_A, usb_bulk_write
works and the program completes execution but I get a message in dmesg that
says this:

[ 1129.201072] usb 2-6: usbfs: process 13739 (spitest) did not claim
interface 1 before use

3. If I try to claim interfaces A-D (I have the FT4232), then the same thing
happens as in 2 above where I get program to complete execution and a new
message in dmesg is shown.  This leads me to believe that INTERFACE_A is
claimed here?

So here is my question ... Does the dmesg message as talked about in 2 above
a concern?  Or is this normal behavior?

I haven't gotten far enough yet to test whether I do actually have control
over all the interfaces and that is my next step but if you see anything of
concern, let me know.

Thanks!


On Wed, Nov 17, 2010 at 11:49 AM, Thomas Jarosch <
thomas.jaro...@intra2net.com> wrote:

> Hello Newell,
>
> On 11/08/2010 04:27 AM, Newell Jensen wrote:
> >>>> buf0 = chr(ftdi.TCK_DIVISOR) # command "set divisor"
> >>>> buf1 = chr(div & 0xFF)  # NOTE: I have also tried using chr((div >> 0)
> & 0xFF) as well
> >>>> buf2 = chr(((div >> 8) & 0xFF))
> >>>> buf = buf0 + buf1 + buf2
> >>>> ftdi.ftdi_write_data(ftdic, buf, 3)
> > -110
> >
> > So that is one issue I run into.  That is, where the disabling of the 5X
> works but the other clock divisor setting doesn't.  Something interesting is
> if I do the above without disabling the 5X, then it works.  Any ideas on
> this?
>
> Hmm. No idea right now. Could you come up
> with a small C example code to demonstrate the issue?
>
> > 2. The second issue I run into is setting the loopback after setting the
> clock divisor above (so I am not disabling the 5X so that I proceed on in my
> script to the loopback setting).  When I go to disable or enable the
> loopback I get usb bulk write fail from the command below:
> >
> >>>> ftdi.ftdi_write_data(ftdic, chr(ftdi.LOOPBACK_START), 1)
> >
> >
> > Any help would be greatly appreciated as at this point I am just
> scratching my head.
>
> Never used that either. Though I'm not sure
> if the ftdi.ftdi_write_data is the correct function
> when using the python wrapper: ftdi_write_data() calls
> usb_bulk_write(). Configuration changes inside
> libftdi are normally communicated via usb_control_msg()
> and also feature different "requests". Not sure
> how you emulated that via the python wrapper??
>
> Cheers,
> Thomas
>
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