Re: [libusb] setCurrentAlternateSetting failed on second device.

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

Michal Weglicki wrote:
>
> I'm using libusb 1.0.19 for Windows. 
>
> On the other side I have devices (my creation) made on xmega. 
>
> All devices are exactly the same (same MCU, same SW, same HW). 
>
> I have following problem: 
> - When starting application and enumerating through devices, first
> device, is initialized properly (claim interface/set alt settings...)
> but second is always failing on setCurrentAlternateSetting with error
> code (translated - I'm not sure what is the default error text in
> english) : 
>
> [31] Device connected to computer is not working. 
>
> I'm sharing same libusb_context for two devices? Is this is a problem?

Since you mention alternate settings, that almost certainly means you
are using isochronous pipes.  In that case, what is almost certainly
happening here is that there is not enough bandwidth to satisfy the
needs of the second device.  What are the bandwidth requirements of your
isochronous endpoints?

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