Subject: Re: new si and reselects
To: None <Ian.Dall@dsto.defence.gov.au>
From: Gordon W. Ross <gwr@mc.com>
List: port-sun3
Date: 12/05/1995 13:20:55
> Date: Tue, 5 Dec 1995 10:49:40 +1030
> From: Ian Dall <dall@hfrd.dsto.gov.au>


> "Gordon W. Ross" <gwr@mc.com> writes:
[ On the problem with SCSI commands with length 10 ]

> I am seeing the same problem attempting to copy the the mini-root from
> to a Fujitsu disk (can't remember the model off hand, built in scsi
> interface).
> 
[ When it happens, just continue... ]

> What happens then? If the command is rejected you still can't
> read/write to the disk unless the driver does something smart to
> compensate.

The command will just fail.  (Yeah, not great.)

> But there is no gdb on the ram disk and I don't get a "db>" prompt
> either.  After the error message I just get the shell prompt back.
> 
>   Gordon> I have only seen this protocol disagreement with the "si" driver
>   Gordon> talking to an Emulex SCSI/ESDI target adapter (common on 3/260).
>   Gordon> Your "QUANTUM EMPIRE_1080S" appears to have the same problem.
> 
> This is a problem for me. I have two disks for my 3/50. The above
> mentioned Fujitsu and a "Sun" disk which is really a Toshiba with the
> above target adaptor. I was thinking of swapping the disks around so
> the Toshiba would be the root disk (instead of the Fujitsu) but if
> what you say about the emulux controller is true it looks like I am
> hosed either way.
> 
> Autoconf finds the disks OK and edlabel can print the partition table
> (I haven't tried writing it since it is already partitioned
> satisfactorilly).

[ Our driver uses READ_LONG (opcode 28) ... ]

> I have used the disk satisfactorilly under SunOs and Mach3. I don't
> know about the former, but the latter uses short read/write commands
> unless the parameters are such that extended read/write commands are
> necessary. For a small disk, this may always be the case, which could
> be why I have never seen the problem before.

Yes, we should make the sd.c driver use "normal" read/write opcodes
when the block numbers fit in three bytes.

> Any suggestions? Those emulux controllers were "standard" peripherals
> for the 3/50 and 3/60 shoe boxes so supporting installation onto them
> is pretty desirable.
> 
> Ian

It's on the todo list...

Gordon