Simon Hobson <linux@???> writes:
> Rainer Weikusat <rweikusat@???> wrote:
>
>> Reportedly, Linux hotplug already had the same problem.
>
> OK, that's what I'd have been seeing in the past then.
>
>> During initialization, the kernel walks through the bus or busses it
>> finds in order to locate all devices and enables them by calling the
>> responsible driver init routines with information about the physical
>> devices which were found. This means the names will be stable if all
>> needed drivers are compiled into the kernel (in absence of deliberate
>> sabotage by the drivers themselves).
>>
>> If there's no compiled-in driver for some device, a so-called hotplug
>> event is generated

| What happens then is entirely the
| responsibility of the userspace software processing these events.

> Right. That explains a lot. So if the driver is built in then devices
> will be stable and determinate, if not then they won't.

They won't in certain cases (if there are devices sharing a namespace,
eg ethX or sdX, but using different drivers) unless the abovementioned
userspace software takes care of this.

Assuming hotplug already had this problem (I never encountered it), it
was probably completely ignored on the grounds that it only happens
'rarely'. One of the reasons udev came into being was to support abitrary
'naming policies' via udev rules.