Re: udev and ISA network cards

[Olaf <mailinglists@ban-solms.de>]

Hi Hannes,


thanks for your thoughts!

> udev relies on device autodetection, ie a (hardware) device must
> have some means by which someone else can identify it.
> With PCI this is no problem at all, as each device has its
> vendor/device ID as per spec.
> 
> ISA OTOH is a different beast. And if you trawl memory back to
> the ISA days, the main problem with it was that it _doesn't_
> have an independent identifier.
> IIRC you couldn't even identify the slot itself; each device
> mostly hardcoded to use a specific I/O address / region and
> some IRQ. And it was up to the task of the admin to ensure
> each device got a separate addr/irq tuple.


For ISA (and PCI, USB, etc.) I use an additional method and do not fully 
rely on autodetection to work.

In my case I have some sort of network configuration file, which 
includes kernel modules, option if so required (i.e. ISA port addresses, 
IRQs etc.) and the things needed for if up.
My network init script uses this config file to modprobe first and then 
configure each interface.


> Hence they invented PnP IDs which provide for exactly this
> sort of identifier.
> 
> So, translated to udev this means that any ISA card providing
> PnP IDs should work, or at least it should be possible to make
> it work with udev.
> Any ISA card _not_ providing PnP IDs you're basically out of luck.
> The only choice you'd have here is to use some sort of lookup-table
> which provides a static assignment between IO addresses and drivers.

The only problem I face is the lack of autodetection, so the config file 
needs to be filled more or less manually. But there is not much one can 
do about that with ISA cards.


OK, I have one additional problem, and that is the udev net device 
renaming which is (understandably) not working with ISA cards ;-)


thanks

Olaf