diff --git a/drivers/net/sfc/net_driver.h b/drivers/net/sfc/net_driver.h
index 5fffd9a..4762c91 100644
--- a/drivers/net/sfc/net_driver.h
+++ b/drivers/net/sfc/net_driver.h
@@ -645,7 +645,6 @@
  * struct efx_nic - an Efx NIC
  * @name: Device name (net device name or bus id before net device registered)
  * @pci_dev: The PCI device
- * @port_num: Index of this host port within the controller
  * @type: Controller type attributes
  * @legacy_irq: IRQ number
  * @workqueue: Workqueue for port reconfigures and the HW monitor.
@@ -729,7 +728,6 @@
 struct efx_nic {
 	char name[IFNAMSIZ];
 	struct pci_dev *pci_dev;
-	unsigned port_num;
 	const struct efx_nic_type *type;
 	int legacy_irq;
 	struct workqueue_struct *workqueue;
@@ -832,7 +830,7 @@
 
 static inline unsigned int efx_port_num(struct efx_nic *efx)
 {
-	return efx->port_num;
+	return efx->net_dev->dev_id;
 }
 
 /**