return NULL;
 }
 
-static unsigned int nfp_net_pf_get_num_ports(struct nfp_pf *pf)
+static int
+nfp_net_pf_rtsym_read_optional(struct nfp_pf *pf, const char *format,
+                              unsigned int default_val)
 {
        char name[256];
        int err = 0;
        u64 val;
 
-       snprintf(name, sizeof(name), "nfd_cfg_pf%u_num_ports",
-                nfp_cppcore_pcie_unit(pf->cpp));
+       snprintf(name, sizeof(name), format, nfp_cppcore_pcie_unit(pf->cpp));
 
        val = nfp_rtsym_read_le(pf->cpp, name, &err);
-       /* Default to one port/vNIC */
        if (err) {
-               if (err != -ENOENT)
-                       nfp_err(pf->cpp, "Unable to read adapter vNIC count\n");
-               val = 1;
+               if (err == -ENOENT)
+                       return default_val;
+               nfp_err(pf->cpp, "Unable to read symbol %s\n", name);
+               return err;
        }
 
        return val;
 }
 
+static int nfp_net_pf_get_num_ports(struct nfp_pf *pf)
+{
+       return nfp_net_pf_rtsym_read_optional(pf, "nfd_cfg_pf%u_num_ports", 1);
+}
+
 static unsigned int
 nfp_net_pf_total_qcs(struct nfp_pf *pf, void __iomem *ctrl_bar,
                     unsigned int stride, u32 start_off, u32 num_off)
 
        mutex_lock(&pf->lock);
        pf->max_data_vnics = nfp_net_pf_get_num_ports(pf);
+       if ((int)pf->max_data_vnics < 0) {
+               err = pf->max_data_vnics;
+               goto err_unlock;
+       }
 
        ctrl_bar = nfp_net_pf_map_ctrl_bar(pf);
        if (!ctrl_bar) {