RTW_USB_MAX_RXTX_COUNT
rtwusb->usb_data = kcalloc(RTW_USB_MAX_RXTX_COUNT, sizeof(u32),
rtwusb->usb_data_index = (idx + 1) & (RTW_USB_MAX_RXTX_COUNT - 1);
rtwusb->usb_data_index = (idx + 1) & (RTW_USB_MAX_RXTX_COUNT - 1);