Re: FW: Parallel Tape vs. PacketTwin - pt name clash (fwd)
Wed, 29 Jul 1998 12:12:07 -0400 (EDT)

> The Right Thing to do would be option 1 (change the parallel tape
> device and driver since it stomped on an existing device).

I would agree in principle, but I think you missed some of the subtleties

This happened many months ago - nobody noticed until last week.

> Option 3 would be ok, except you are assuming that no one is
> maintaining the PacketTwin driver, and no one has written
> software that depends on the pt driver being the PacketTwin.
> (I would look to the person who wrote / maintains the PacketTwin
> driver and discuss the possible problems with this option before
> attempting to do this.) It also sets a bad precedent for changing
> device names because someone else wants to use that name.

The PacketTwin driver is not exposed to userland. The only place the
name matters is during kernel configuration. And, as Alan Cox has
already pointed out, there are very few users for it.

> Option 4 is not nice, ignoring a problem will only create larger
> ones later. A person using SuSE decides they need PacketTwin
> support, so they grab a kernel source tree and compile their own
> and boom - instant problem.

No, only if they also have a parallel port atapi tape drive.

> Option 5 is not a good option, you claim it will only happen to people
> who are making distributions. I claim it could happen to anyone who
> copiles their own custom kernel.

If they happen to have both pt devices and they build them as modules.
Only distribution builders make "kitchen sink" kernels. If this had
been a serious _practical_ problem, it would have been detected long ago.

> Basically I see this as a person having great intentions, creating a
> useful piece of software, but not following through on the development
> by researching the driver name before releasing the driver to the world.

Please spare me the attitude.

> This raises the question - who is responsible for coordinating device
> driver names and numbers for the kernel? If no one is, this will happen
> again in the future as support for more devices are added by more people
> with less experience.

You are barking up the wrong tree there. There _is_ already a registry
for device major numbers and the corresponding names. It covers all
drivers that have entries in /dev. The pt tape driver was duly approved
and allocated by the maintainer of that registry.

But, network drivers, and lots of other modules, for that matter, are
not "devices" in the unix sense and have no entries in that registry.
That is why this situation arose.

The real problem is that modules occupy a flat name space. Michael
Chastain has already proposed a solution.

Grant R. Guenther

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