Re: "do ata" scsi command?

[Jens Axboe <axboe@suse.de>]

On Fri, May 16 2003, Jeff Garzik wrote:
> Jens Axboe wrote:
> >On Thu, May 15 2003, Jeff Garzik wrote:
> >
> >>In terms of a userspace interface for my ata-over-scsi gadget, I would
> >>prefer to use /dev/sg instead of inventing a totally new interface.
> >>That, in turn, implies a need for a "do ata taskfile" scsi command,
> >>which is sorta like ATAPI in reverse:  we are wrapping a raw ata
> >>taskfile inside a scsi cdb.
> 
> 
> Based on private responses as well as Jens' response, I think my initial 
> post must have been terribly unclear.  Let me restate:
> 
> I have chosen the standard, existing scsi-generic nterface as the one by 
> which raw taskfiles will be sent to devices.  The taskfile will be 
> wrapped inside a SCSI cdb.  To me this solution is the most flexibility 
> for least cost.

Aha, and how do you wrap an ata command nicely into a scsi cdb? I can
only see it getting ugly.

> So, what opcode do I choose for "send taskfile"?  Either (a) pick a 
> vendor-specific one, or (b) someone else already chose an opcode.
> 
> So my post was really these questions:  a or b?  if b, what opcode?

Irk! I can't believe you are suggesting something like this. Jeff,
please do yourself a favor and think about what you are saying for a
second.

> (see, existing interfaces satisfy my needs :))

I can transport maneur on the back seat of my car if I needed to,
doesn't necessarily make it a brilliant idea just because it's doable.

-- 
Jens Axboe