IBM DFHS S2W drive problem (scb related?)

[Steven N. Hirsch]

On 7 Feb 1998, Rob Browning wrote:

> 
> I'm trying to attach an IBM DFHS S2W drive (it's a wide drive) to a
> 2940 with a 9GB barracuda.  The card recognizes and spins up the
> drives, but when the OS level scsi driver loads and gets to the point
> of recognizing the IBM, it prints "sending SDTR!" message followed
> immediately by a blur of SCSI bus reset messages.  I can't read them
> clearly, because it's in a tight loop, but I was able to gather these
> snippets (their order may be wrong):
> 
>   Issuing bus device reset
>   Bus device reset delivered, 1 SCBs aborted
>   Aborting scb0
> 
> There's more info printed in the loop, but I can't read it well enough
> to write it down.  I thought I recalled someone posting about a
> similar problem a couple of months ago, but I wasn't sure.  Does
> anyone recall, or Is there an archive of the list somewhere?
> 
> Any help would be appreciated...
> 

My sympathies!  This drove me crazy with my DFHS S4W until a user in
Germany pointed out that IBM drives are shipped with the Dque bit set in
the configuration page.  So, the drive reports that it is capable of
tagged command queueing in the mode sense, but fails miserably when the
controller actually tries to use it...

I suggest rebuilding the aic7xxx driver with tagged queueing disabled.
This will let the machine boot.  Once you have it up and running, use a
utility like scsi-config (available on sunsite, I believe) to clear the
Dque bit and save the page to the drive.

Then, reenable tagged queueing, reboot, and enjoy.

Steve



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