Re: [avrdude-dev] jtag2 and usb timeout

[Dave N6NZ]

I instrumented avrdude and found that usb_bulk_read() is returning -110, 
which (if I am reading errno.h) correctly is a time out.  usb_strerror() 
is not returning a sensible value, however, it claims "No error".

Stretching the time-out value passed by avrdude causes the failure to 
take longer, so it would seem that the time out is legitimate.

I'm thinking that there is a basic connectivity issue in the USB 
configuration someplace. It's not permissions, it fails the same way 
running as root. It's not hardware/cabling, Windows works fine.

-dave

Joerg Wunsch wrote:
> As Dave N6NZ wrote:
>
> > It really appears that libusb is returning an error status, without
> > setting an error code.  Possibilities:
>
> > 1) spurious error code for correct operation
> > 2) missing error code for incorrect operation
> > 3) Dave is too tired to be reading code and is totally lost.
>
> I've got similar problems on one laptop running Linux at work.  Almost
> the same system as on our lab machines (some version of SuSE), but
> while everything works fine on the lab systems (once the admin figured
> out how to assign the /proc/usb/... entries for the JTAG ICEs to us
> mortal users), it fails on the laptop, experiencing similar symptoms
> as your setup.  So far, the only workaround on the laptop has been to
> use the RS-232 connection instead.  Never had any such problem on the
> lab systems running Linux, nor on my FreeBSD machines at home.  (I've
> occasionally got trouble on FreeBSD with AVaRICE connecting over USB
> where it apparently drops some bytes from the connection internally,
> but AVaRICE's USB handling is a lot different from AVRDUDE's, mainly
> due to hysterical raisins, and due to AVaRICE being in need to listen
> to both, USB and the GDB channel.)
>
> I suggest you try contacting the libusb developers to see what kind of
> debugging could be applied.  If you've got any solution, please post
> it here.