Subject: Re: Cardbus
To: None <>
From: Ken Hornstein <>
List: tech-kern
Date: 12/27/1999 13:01:17
>	Although I do not believe there's sole "ultimate" solution for pcmcia
>	device model, I still believe BSDI's approach is good.

Can some people elaborate on this more?  I've heard a lot about it, but
I haven't had access to a BSDI box in literally years, so I'm not
sure exactly _what_ they do!

>	Traditionally UNIX assumes there will be no changes made to device
>	attach/detach during its runtime.  Because of it UNIX do not really
>	have a good way to notify of changes to the userland programs, and
>	not many userland programs are designed to be adaptable to those
>	changes.  I think that we may need to hide those dynamic changes to
>	network devices (interface removal, pcmcia slot power down and
>	other things) from the userland programs to "preserve" traditional,
>	not-too-many-changes-to-list-of-devices view from uesrland.

Certainly we do interface creation with pcmcia today, and it's not too
problematic.  What exactly breaks when an interface gets deleted?  I guess
this is hard to predict since we don't delete interfaces now, but give
us some ideas.

>	(you are free to argue that they are not well written, but this is
>	the way it was for a long years, until notebook PCs are around)

I think I'm with Lennart on this one; we should fix these programs.
It can be something as simple as "rescan interface list on receipt
of a SIGHUP".