Re: [libusb] Transfer timeout

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

dus...@em... wrote:
>
> my host app (libusb on Win 10) reads some data from interrupt IN and 
> bulk IN endpoint from my USB device. Sometimes the app stops reading 
> the data from e.g. interrupt IN endpoint, libusb_interrupt_transfer on 
> that endpoint always returns -7 (timeout) with zero data transfered. 
> The USB device has some data prepared to be transfered but there is no 
> incoming request from the host (no usb interrupt routine is called at 
> the device side for libusb_interrupt_transfer call).

When you get that timeout, do you resubmit the read request?


> I also noticed that in this state, my device is not detected by Device 
> Monitoring Studio (usb analyzer software). It is visible in Windows 
> Device Manager.

If some endpoints are working, I'm not sure why it wouldn't show the 
device.  Do you see error just at the point where the read times out?  
What you describe could be caused by an endpoint stall, but that would 
be a device problem.

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