[[e-mail]: Re: [linux-usb-devel] Re: /proc/scsi/map]

[Kurt Garloff]

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Hi,

forgot to Cc: the other recipients.=20
I did not want to turn this into a private discussion.

----- Forwarded message from Kurt Garloff <[e-mail]> -----

Date: Mon, 17 Jun 2002 02:46:24 +0200
From: Kurt Garloff <[e-mail]>
To: James Bottomley <[e-mail]>
Subject: Re: [linux-usb-devel] Re: /proc/scsi/map
In-Reply-To: <[e-mail]>
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Hi,

On Sun, Jun 16, 2002 at 06:14:33PM -0500, James Bottomley wrote:
> [e-mail] said:
> > But the drivers already know, or would have to be taught to know about
> > it. Somewhence that information has to come. You cannot avoid that
> > effort.=20
>=20
> Not necessarily: consider the SCSI WWN, which is supported by most modern=
 SCSI=20
> devices.  The driver never probes for or asks for this.  Nowhere in the=
=20
> current SCSI code do we ask for this.  However user level commands (like=
=20
> sg_inq) can formulate the 0x83 page inquiry to get this and return the ou=
tput.=20
>  This works today with the current driver.

This may work for your disks. You just can't open the device node for a
tape, if there is no medium inserted. If you know the mapping between
to a sg device you can use it.
That's the second piece of information that /proc/scsi/map provides.

The first piece is that the kernel tells kernel tells you the way it is
attached by reporting CBTU, which is a good identifier for good old parallel
SCSI that most of our SCSI code still is assuming.

That will change one day ...

Regards,
--=20
Kurt Garloff                   <[e-mail]>         [Eindhoven, NL]
Physics: Plasma simulations    <[e-mail]>     [TU Eindhoven, NL]
Linux: SCSI, Security          <[e-mail]>    [SuSE Nuernberg, DE]
 (See mail header or public key servers for PGP2 and GPG public keys.)

----- End forwarded message -----

--=20
Kurt Garloff                   <[e-mail]>         [Eindhoven, NL]
Physics: Plasma simulations    <[e-mail]>     [TU Eindhoven, NL]
Linux: SCSI, Security          <[e-mail]>    [SuSE Nuernberg, DE]
 (See mail header or public key servers for PGP2 and GPG public keys.)

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