The sysfs field was introduced 4 years ago along with fixes to various drivers that erroneously used `dev_id' for that purpose, but it was not properly documented anywhere. See commit v3.14-rc3-739-g3f85944fe207. Signed-off-by: Arseny Maslennikov <ar@xxxxxxxxx> --- Documentation/ABI/testing/sysfs-class-net | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-class-net b/Documentation/ABI/testing/sysfs-class-net index 2f1788111cd9..ec2232f6a949 100644 --- a/Documentation/ABI/testing/sysfs-class-net +++ b/Documentation/ABI/testing/sysfs-class-net @@ -91,6 +91,24 @@ Description: stacked (e.g: VLAN interfaces) but still have the same MAC address as their parent device. +What: /sys/class/net/<iface>/dev_port +Date: February 2014 +KernelVersion: 3.15 +Contact: netdev@xxxxxxxxxxxxxxx +Description: + Indicates the port number of this network device, formatted + as a decimal value. Some NICs have multiple independent ports + on the same PCI bus, device and function. This attribute allows + userspace to distinguish the respective interfaces. + + Note: some device drivers started to use 'dev_id' for this + purpose since long before 3.15 and have not adopted the new + attribute ever since. To query the port number, some tools look + exclusively at 'dev_port', while others only consult 'dev_id'. + If a network device has multiple client adapter ports as + described in the previous paragraph and does not set this + attribute to its port number, it's a kernel bug. + What: /sys/class/net/<iface>/dormant Date: March 2006 KernelVersion: 2.6.17 -- 2.19.0.rc2
