Subject: Re: Cardbus
To: None <tech-kern@netbsd.org>
From: Ken Hornstein <kenh@cmf.nrl.navy.mil>
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".
--Ken