MTK_VCP_MBOX_SLOT_MAX_SIZE
priv->ipi_recv.msg = devm_kzalloc(dev, MTK_VCP_MBOX_SLOT_MAX_SIZE,
MTK_VCP_MBOX_SLOT_MAX_SIZE / 4);
if (ipi_info->slot_ofs + ipi_info->len > MTK_VCP_MBOX_SLOT_MAX_SIZE)