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Date: Sat, 23 Mar 1996 11:53:26 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199603230053.LAA32215@godzilla.zeta.org.au>
To: bde@zeta.org.au, pst@shockwave.com
Subject: Re: modloaded block/char device drivers
Cc: bde@FreeBSD.ORG, bugs@FreeBSD.ORG, hackers@FreeBSD.ORG, jmz@FreeBSD.ORG
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>It seems to me, we need something like a top half and a bottom half of
>the kdc, the top half stays with the driver (i.e. belongs to qcam or lpt)
>and the bottom half stays with the hardware.  Then opening either device
>would lock out the other device.

Using open to lock the device doesn't work so well for network devices.
We already have many warty examples: slip, ppp and plip.

Bruce