Re: [gentoo-user] Re: udev (viable) alternatives ?

[Samuli Suominen <ssuominen@gentoo.org>]

On 26/09/14 11:22, Canek Peláez Valdés wrote:
> On Fri, Sep 26, 2014 at 3:07 AM, Neil Bothwick <neil@digimed.co.uk> wrote:
>> On Fri, 26 Sep 2014 05:27:15 +0200, Alan McKinnon wrote:
>>
>>>>   I buy machines with one ethernet interface.  What I find
>>>> particularly annoying is this doublespeak about calling it
>>>> "predictable".  Before the change, it was predicatbly "eth0".  Now,
>>>> it's different on every different model.
>>> It's not doublespeak, the interfaces are named exactly according to
>>> where they are on the PCI bus. If you had two interfaces, they show up
>>> to the kernel in random order by time and sometimes eth0/eth1 are nto
>>> the same they were before the reboot.
>> That may be true for PCI devices but not for USB ones. If you unplug a
>> USB device and plug it back into the same port, it will get a different
>> device number. The naming is more predictable, but it's not there yet.
> That doesn't sound right. If unplugging a USB net device and plugging
> it again *in the same port* results in a different device *name*, then
> it is a bug and should be reported; the description of the algorithm
> in [1] sounds like it should get always the same name for the same
> port, unless I'm misunderstanding something.
>
> Regards.
>
> [1] http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n51

I've seen this happening once on a cheap laptop with a stripped down
BIOS I can't
even recall brand for, it had a kludge in the BIOS settings for
hotplugging, turning
it off, allowed the port to remain same, turning it on, some machine
specific code
gets executed and the kernel interprets the same port as different port

Bad hardware, bad hardware settings, maybe missing exception for that
particular
hardware type in the code that determines the name... I'm not sure, I
don't have
the machine anymore

- Samuli