MC_CMD_INIT_TXQ_IN_LEN
EFX_MCDI_DECLARE_BUF(payload, MC_CMD_INIT_TXQ_IN_LEN(EFX_TXQ_MAX_BUFS),
if (MC_CMD_INIT_TXQ_IN_LEN(npages) > sizeof (payload)) {
req.emr_in_length = MC_CMD_INIT_TXQ_IN_LEN(npages);