Hello!

On 8/29/2018 12:01 AM, Arseny Maslennikov wrote:

Some InfiniBand network devices have multiple ports on the same PCI
function. Prior to this the kernel erroneously used the `dev_id' sysfs
field of those network interfaces to convey the port number to userspace.

`dev_id' is currently 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'.

    See commit 76a066f2a2a0 ("net/mlx4_en: Expose port number through sysfs").

This commit is separated from the previous one since we may wish to
preserve backwards compatibility with userspace being already dependent
on `dev_id' being different.

Signed-off-by: Arseny Maslennikov <redacted>

[...]

MBR, Sergei