How to start a bulk transfer for a superspeed uvc camera on win8&win8.1? RRS feed

  • Question

  • Hi all

    I'm writing a driver for a USB3.0 uvc camera. I want know how to correctly set URB for superspeed bulk transfer. As we know, the superspeed bulk  MaximumTransferSize on win8/8.1 is 32M, and when driver negotiation with device, I can get the dwMaxPayloadTransferSize from device, it's 0x2000, which length should I use for URB data block? I did some test.

    •  1 URB, length is 32M, it doesn't work
    • submit a 2048 URBs queue, data block is 0x2000, it works on win8, but does't work on Win8.1.

    Is the second way is right? Why it doesn't work on Win8.1? Is this related about different host controllers?


    Monday, November 10, 2014 10:30 AM