Hi Alan, Another question. According to the USB spec: """ The Data stage of a control transfer from an endpoint to the host is complete when the endpoint does one of the following: * Has transferred exactly the amount of data specified during the Setup stage * Transfers a packet with a payload size less than wMaxPacketSize or transfers a zero-length packet """ AFAIU, this means that a device only needs to send a zero-length packet when the last data packet happened to be equal to wMaxPacketSize to indicate that the data stage is over. Gadgetfs seems to be doing something different, it sets the req->zero flag (for the response passed to usb_ep_queue) when value < w_length, where value is the length of the response being submitted and w_length is the value of the wLength field of the control request. Is there something I misunderstand? Thanks!
