GUD_FORMATS_MAX_NUM
formats_dev = devm_kmalloc(dev, GUD_FORMATS_MAX_NUM, GFP_KERNEL);
formats = devm_kmalloc_array(dev, GUD_FORMATS_MAX_NUM + 1, sizeof(*formats), GFP_KERNEL);
ret = gud_usb_get(gdrm, GUD_REQ_GET_FORMATS, 0, formats_dev, GUD_FORMATS_MAX_NUM);