Re: [Libusb-devel] ISOC support for Libusb 1.0 for windows 7

[Pete B. <pe...@ak...>]

On 2012.03.22 18:36, Kenneth Schultz wrote:
> I am running libusb 1.0.8 on windows 7 and I was trying to get very simple ISOC out/in transfers to work but they keep failing.

If the libusb.org site was up, you would be able to get the following 
information with regards to the Windows implementation:

Known Restrictions
==================

o WinUSB cannot be used to send an actual reset command to an USB 
device. This is a limitation of the Microsoft driver.
o WinUSB cannot be used to set a device configuration that is different 
from the default one. This is a limitation of the Microsoft driver.
o WinUSB does not support multiple concurrent applications (as per the ​ 
MSDN documenation).
o WinUSB does not support isochronous transfers.
o When using interface control requests (LIBUSB_RECIPIENT_INTERFACE), 
WinUSB overrides the low byte of wIndex with the destination interface. 
This is a limitation of the Microsoft driver.
o Because there is no native poll on Windows, the ability to return 
externally pollable file descriptors on Windows (​libusb_get_pollfd) 
returns an error.

As you see from item #4, the driver we use (WinUSB) does not support 
isochronous transfer. There are some plans to add more Windows drivers, 
including ones that support ISOC, but it's impossible to say when that 
will happen at this stage.

Regards,

/Pete