Subject: Re: sudden detach
To: Garrett D'Amore <garrett_damore@tadpole.com>
From: Bill Studenmund <wrstuden@netbsd.org>
List: tech-kern
Date: 07/12/2006 07:35:51
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On Wed, Jul 12, 2006 at 07:19:27AM -0700, Garrett D'Amore wrote:
> John Nemeth wrote:
> > On Dec 1,  7:38am, "Garrett D'Amore" wrote:
> > } drivers are generally _not_ hotplug safe.
> >
> >      What about PCI Hot-Plug?  Sounds to me that if drivers can't
> > handle sudden detach now, they will need to do so in the future.
> >  =20
>=20
> All PCI hotplug systems that I'm familiar with use a command to
> deconfigure the device before removal first.  CompactPCI even has LEDs
> to indicate "safe-to-remove" status, IIRC.
>=20
> So in  the case of PCI, you _don't_ deal with "sudden detach".  You deal
> with "controlled, prenotified detach".

The deep problem I see with this is that, as long as the cards do not have=
=20
physical latches controlled by the OS, you will never be able to totally=20
prevent unexpected removal. :-(

I agree it _shouldn't_ happen, and I agree we should be grumpy about it.=20
But I think we should be able to cope with sudden removal.

Take care,

Bill

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