[systemd-devel] Match section of .link file not working

Kay Sievers kay at vrfy.org
Mon Aug 25 10:46:41 PDT 2014

On Mon, Aug 25, 2014 at 7:25 PM, Lennart Poettering
<lennart at poettering.net> wrote:
> On Sun, 24.08.14 06:49, Simon Peeters (peeters.simon at gmail.com) wrote:
>> >> This should be the value of ID_PATH property, not sysfs path. Check with
>> >>
>> >> udevadm info --query
>> >> property /sys/devices/ocp.3/47400000.usb/musb-hdrc.1.auto/usb1/1-1/1-1:1.0/net/wlv3
>> >
>> > oops, I confused ID_PATH with DEVPATH, now i feel like an idiot.
> ID_PATH is basically the "reduced + stable" part of the full sysfs path.
>> Ok, so there is only one problem now:
>> ID_PATH is the same for all my vif interfaces, and i need to select
>> only one of them.

ID_PATH usually describes the "parent hardware", and the same hardware
can have multiple independent devices. Unique names for several
devices need to be composed by appending something to the "parent

I don't have a good idea what a working model for your case would be,
where multiple devices share the same parent. This is not a common

> This is some embedded device with your hw connected to some platform
> bus?
> Currently the ID_PATH logic doesn't understand platform busses (since it
> is not clear how "stable" they are). This has come up before, and could
> probably be fixed. Maybe we should assume that platform busses are
> always enuemrated in a stable way, dunno.
> Kay probably has something useful to say here. Kay?

Special buses need explicit support in the code if ID_PATH is not
generated, but that does not look like the problem here.

Seems the USB interface exports 3 different network devices. Do they
have any unique property? Like dev_id, dev_port in /sys? Or are the
types of the netifs unique?

If anything like that is available, that could be appended to the
parent ID_PATH string and identify the device uniquely, if you get
what I mean.


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