From: Pete B. <pb...@gm...> - 2010-11-12 11:13:46
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Hi Chris, On 2010.11.12 03:20, Chris Frey wrote: > It was a slight surprise to find that when I tried to use the experimental > windows backend (pbatard's git repo) that I received -12 (NOT_SUPPORTED) > on a libusb_open() call. Can you provide an excerpt of the code you use, and the device you were trying to address. Please be advised that, unlike what is the case on Linux, where the OS provides a default generic driver that libusb can use to have full access to the device, on Windows libusb_open() will only ever work if your device uses a driver that provides a generic API that libusb supports, and will be bound by the limitations of that driver. Currently that means only WinUSB.sys or HidUSB.sys (and to a *very* limited extent UsbHub.sys) are supported from the Windows backend. Anything else, like mass storage or proprietary driver, or even libusb0.sys from libusb-win32, will return NOT_SUPPORTED. To access your device will libusb 1.0 then, you should first ensure that you are using a compatible driver. Of course, if you replace an existing driver, operations that relied on the old driver will no longer be available. Please see http://libusb.org/wiki/windows_backend#DriverInstallation for more details on installing a libusb compatible driver. > Is the Windows backend capable of doing simple synchronous bulk transfers > on Windows XP, under Cygwin? If you mean isochronous transfers, this is currently not supported due to limitations of the WinUSB driver: http://www.libusb.org/wiki/windows_backend#KnownRestrictions We have plans to implement support for the custom libusb0.sys driver from libusb-win32 in the future, that supports isochronous transfers, but currently, it is impossible to say when that will happen. Regards, /Pete |