hi all: when i trace xhci source, I found in skip_isoc_td, there is a possibility to increase de-queue pointer twice. in skip_isoc_td: /* Update ring dequeue pointer */ while (ep_ring->dequeue != td->last_trb) inc_deq(xhci, ep_ring); inc_deq(xhci, ep_ring); why (ep_ring->dequeue != td->last_trb) we have to increase the dequeue pointer? I try to find any description in spec about this but in vain. is there any special reason to do so? appreciate your kind help, -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html