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Date: Wed, 6 Aug 1997 21:30:42 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199708061130.VAA15302@godzilla.zeta.org.au>
To: msmith@atrad.adelaide.edu.au
Subject: Re: canonical issue wrt DMA & wd/wdc
Cc: current@FreeBSD.ORG, ggm@connect.com.au
Sender: owner-freebsd-current@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk

>> > 2) flags 0x80ff80ff blows up in config on wdc but works on wd<n> instances
>> 
>> This is nonsense; you can't put flags on 'wd' instances, and it works
>> fine on 'wdc' (the only place you _can_ put it).
>
>Yeep.  Re: later messages on this thread, 'disk' is a subclass of
>'device', so of course you can put flags on them.  

The driver ORs the flags together (the low 16 bits of the disk flags with
the relevant 16 bits of the controller flags).  This seems to be a hack
to let the flags be configured by userconfig.  Userconfig neither sets
nor displays the disk flags, so you should never set them if you ever
use userconfig, since the unseen flags are at best confusing.

Bruce