Subject: Re: aix7xxx problems with negotiating "Ultra" speeds....
To: None <>
From: Kenneth D. Merry <>
List: current-users
Date: 12/09/1998 18:09:45
Jason Thorpe wrote...
> On Wed, 9 Dec 1998 17:45:46 -0700 (MST) 
>  "Kenneth D. Merry" <> wrote:
>  > > 	(4) Some missing target drivers (show-stopper).
>  > 
>  > Target drivers??  There's only one target-mode driver, and it's a
>  > target-mode processor target driver.  What missing target drivers are you
>  > talking about?
> target driver == "disk", "cd-rom", etc.  SCSI Ethernet is a big deal
> for some of our users, being the only way they can connect to a network.
> Scanners are also currently supported.  I am NOT interested in supporting
> FEWER devices than we do now.

Well, I'll say this much about peripheral drivers.  They're very easy to
port.  In fact, when I did the CAM changer driver, I ported your latest
driver from NetBSD, and it only took a day or so.

A lot of the peripheral driver code is rather boiler-plate, and it's pretty
easy to translate things from the old SCSI layer to the new SCSI layer.

If I had a scanner or a SCSI ethernet device, there would be a peripheral
driver for it already.  If someone wants to port those peripheral drivers,
I'll be glad to help.

As far as scanners go, I think FreeBSD folks have been using SANE, or
xvscan (which probably hasn't been ported to CAM -- no free source).  I
haven't looked much at SANE, or at NetBSD's scanner code, so I can't
comment on the advantages/disadvantages of either one.

>  > > 	(5) Serious lack of documentation (show-stopper, because without
>  > > 	    this, how do we make the plethora of HBA drivers we support
>  > > 	    work?)
>  > 
>  > And how much documentation do you have on the current NetBSD SCSI layer?
> Basically none.  But past errors are no excuse :-)

You'll have to wait, then.  Justin and I have limited time, especially when
our "real" work doesn't always involve CAM.  We're already ahead of the old
SCSI layer, though, since we have the CAM-2 and CAM-3 specs in addition to
the man pages. :)

>  > Matt Jacob (isp) and Warner Losh (aha) have ported HBA drivers to CAM with
>  > only other drivers for documentation and Justin's assistance.  So it is
>  > possible to do.
> Yes, I understand that.  But count the number of HBA drivers in NetBSD,
> and count the number of people who will be doing the work.  A clear,
> concise manual page with even just a basic description of the code path
> would be of great help.

Well, we do plan on writing more documentation.  My personal list of things
to do includes writing man pages for all of the CCB types.  (Look in
sys/cam/cam_ccb.h, and you'll see that it's no small task.)

Justin will have to be the one to write the HBA <-> XPT docs, though.

Kenneth Merry