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Date:      Thu, 13 May 1999 22:05:21 -0700 (PWT)
From:      Matthew Jacob <mjacob@feral.com>
To:        "Justin T. Gibbs" <gibbs@narnia.plutotech.com>
Cc:        scsi@FreeBSD.ORG
Subject:   Re: IBM scsi drives
Message-ID:  <Pine.LNX.4.04.9905132202460.29768-100000@feral.com>
In-Reply-To: <199905140426.WAA20888@narnia.plutotech.com>

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> > 
> > 
> > I've had some reasonable good experiences in some contexts with the IBM
> > drives- but they have a wierd property of not working if your host adapter
> > negotiates sync speeds before negotiating wide. Make sure these drives
> > work for you before you pay!
> 
> It doesn't make much sense to negotiate sync before wide since,
> according to the spec, a wide negotiation invalidates any sync
> setting.  The aic7xxx driver always reverts to async after a wide
> negotiation and will renegotiate sync if appropriate.

So Comte Roudier informed me... I knew that sorta (I really don't need
to know this for the Qlogic cards- this is done in the f/w...)...

I don't really remember all the details and can dig out the fax from an
IBM engineer..but the basic gist of this was I had to (for a Solaris
driver) break the Solaris order of 'first sync then wide'. It's possible I
could have forced renegotiation but it seems to me that there was
something that would make this not work. All of this is the dance between
spec && shipping h/w.




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