HID Force Feedback report descriptor problem - how to debug? RRS feed

  • Question

  • I designed a KMDF driver for HID devices.

    When there's no FFB part in the descriptor, I can load up to 16 devices. I do it by concatenating the single devices, while making sure that the Report ID for each device is unique. For every top collection (Application) Report ID=1 to 16. The devices are functional. So far so good.

    Now, I add an FFB part to the descriptor. One Usage Page Physical Interface per device (Actually, I reduced the number to 2). The devices won't load. So I remove all devices but one from the report descriptor - the single FFB device seems to be fully functional.

    My conclusion is that theres seems to be an error in the full (2xFFB) report descriptor. Any idea how to verify/test the descriptor? Any idea why a corrupted descriptor will prevent a device from loading?

    I cannot attach the 2xFFB descriptor. Here's a link to the file.

    Wednesday, November 12, 2014 10:30 AM

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