Re: [libusb] submit_iso_transfer - errno : 16 , LIBUSB_ERROR_IO

[Tim R. <ti...@pr...>]

mau wrote:
> I am a newbie in libusb, have been trying to implement isochronous
> communication to acquire data continuously from an audio device.

Is there a reason why you can't use the stock system driver and the
normal system audio APIs to do this?  Doing isochronous is not easy.


> When I tried interrupt mode, I got no error in real time. But while I tried
> to implement isochronous transfer, I have been getting a run time error :

Did you change the endpoint type in the descriptors?  You can't do
isochronous transfers on an interrupt endpoint.  The transfers have to
match the endpoint type.


> [submit_iso_transfer] submiturb failed error -1 errno:16
>
> I have been getting the libusb error enum printed: LIBUSB_ERROR_IO
>
> I tried all the end point descirptor, max packet size and bLengths groups,
> but the result does not change.
>
> Might it be related to the kernel; I saw similar problems caused by the
> kernel?

None of us has a crystal ball.  Please show us your code and your
descriptors, and we'll see what you might be doing wrong.

By the way, NEVER blame the kernel first.  The kernel isn't bug-free,
but if you're just starting out, the odds are infinitesimally small that
your problem is a kernel or operating system bug.

-- 
Tim Roberts, ti...@pr...
Providenza & Boekelheide, Inc.