Some InfiniBand network devices have multiple ports on the same PCI
function. This initializes the `dev_port' sysfs field of those
network interfaces with their port number.

The use of `dev_id' was considered correct until Linux 3.15,
when another field, `dev_port', was defined for this particular
purpose and `dev_id' was reserved for distinguishing stacked ifaces
(e.g: VLANs) with the same hardware address as their parent device.

Similar fixes to net/mlx4_en and many other drivers, which started
exporting this information through `dev_id' before 3.15, were accepted
into the kernel 4 years ago.
See 76a066f2a2a0268b565459c417b59724b5a3197b, commit message:
`net/mlx4_en: Expose port number through sysfs'.

Signed-off-by: Arseny Maslennikov <redacted>
---
 drivers/infiniband/ulp/ipoib/ipoib_main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 26cde95bc0f3..6eb0594fffec 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c

@@ -2253,6 +2253,7 @@ static struct net_device *ipoib_add_port(const char *format,
 
 	SET_NETDEV_DEV(priv->dev, hca->dev.parent);
 	priv->dev->dev_id = port - 1;
+	priv->dev->dev_port = port - 1;
 
 	result = ib_query_port(hca, port, &attr);
 	if (result) {

-- 
2.18.0