TAS and Extended Contingent Allegiance

George Penokie gop at us.ibm.com
Wed Sep 22 12:20:15 PDT 2004


* From the T10 Reflector (t10 at t10.org), posted by:
* George Penokie <gop at us.ibm.com>
*
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Mark, 

I don't agree that obsolete is the correct definition in this case. The
problem is that the bit was defined (for better or worst) from reserved
to TAS and has been the new definition since 7/2001 in SPC-2. As near as
I can tell that bit was changed from EECA to reserved in the first
revision of SPC (pre 1994). 

The problem with labeling the bit as obsolete is the definition of
obsolete which is: 

A keyword indicating that an item was defined in prior standards but has
been removed from this standard. 

So if you make it obsolete which standard do you go to to find the
usage. Most would go to the most recent (i.e., SPC-2) which would be the
TAS definition. That does not solve Mark's or my problem. Who would
think to go all the way back to SCSI-2 to find the definition! 

I think the only solution is to mark the bit as vendor specific and
define a new bit with the TAS function. That would allow those that do
use TAS to keep working. And those devices that still define the EECA to
still be compliment. In our case that bit is still defined as EECA, is
set to zero, and non-changeable. 


Bye for now,
George Penokie

Dept 2C6  114-2 N212
E-Mail:    gop at us.ibm.com
Internal:  553-5208
External: 507-253-5208   FAX: 507-253-2880





"Evans, Mark" <Mark_Evans at maxtor.com> 
Sent by: owner-t10 at t10.org 


09/22/2004 11:50 AM 

To
"T10 Reflector" <t10 at t10.org> 

cc

Subject
RE: TAS and Extended Contingent Allegiance

	





* From the T10 Reflector (t10 at t10.org), posted by:
* "Evans, Mark" <Mark_Evans at maxtor.com>
*
Hi Ralph,

I think that the only option is to change the bit to "obsolete".  If
someone requires the TAS functionality, then a new bit should be
assigned.

Regards,

Mark Evans
Maxtor Corporation

-----Original Message-----
From:                  owner-t10 at t10.org [mailto:owner-t10 at t10.org]  On
Behalf Of Ralph O. Weber
Sent:                 Tuesday, September 21, 2004 10:47 AM
To:                 T10 Reflector
Subject:                 TAS and Extended Contingent Allegiance

* From the T10 Reflector (t10 at t10.org), posted by:
* "Ralph O. Weber" <roweber at ieee.org>
*
It has been brought to my attention that SPC-1 changed
bit 7 of byte 4 in the Control mode page from EECA (Enable
Extended Contingent Allegiance) to Reserved.

In SPC-2, the same bit was changed from Reserved to TAS
(Task Aborted Status).

Apparently, some firmware out there still interprets
Control mode page byte 4 bit 7 to mean Enable Extended
Contingent Allegiance.

Since it seems likely that lots of other firmware interprets
the same bit as enabling the sending of TASK ABORTED status,
there may be a nasty problem brewing here.

All the best,

.Ralph

*
* For T10 Reflector information, send a message with
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<br><font size=2 face="sans-serif">Mark,</font>
<br>
<br><font size=2 face="sans-serif">I don't agree that obsolete is the correct
definition in this case. The problem is that the bit was defined (for better
or worst) from reserved to TAS and has been the new definition since 7/2001
in SPC-2. As near as I can tell that bit was changed from EECA to reserved
in the first revision of SPC (pre 1994). </font>
<br>
<br><font size=2 face="sans-serif">The problem with labeling the bit as
obsolete is the definition of obsolete which is:</font>
<br>
<br><font size=2 face="sans-serif">A keyword indicating that an item was
defined in prior standards but has been removed from this standard.</font>
<br>
<br><font size=2 face="sans-serif">So if you make it obsolete which standard
do you go to to find the usage. Most would go to the most recent (i.e.,
SPC-2) which would be the TAS definition. That does not solve Mark's or
my problem. Who would think to go all the way back to SCSI-2 to find the
definition!</font>
<br>
<br><font size=2 face="sans-serif">I think the only solution is to mark
the bit as vendor specific and define a new bit with the TAS function.
That would allow those that do use TAS to keep working. And those devices
that still define the EECA to still be compliment. In our case that bit
is still defined as EECA, is set to zero, and non-changeable.</font>
<br>
<br><font size=2 face="sans-serif"><br>
Bye for now,<br>
George Penokie<br>
<br>
Dept 2C6 &nbsp;114-2 N212<br>
E-Mail: &nbsp; &nbsp;gop at us.ibm.com<br>
Internal: &nbsp;553-5208<br>
External: 507-253-5208 &nbsp; FAX: 507-253-2880<br>
<br>
</font>
<br>
<br>
<br>
<table width=100%>
<tr valign=top>
<td width=40%><font size=1 face="sans-serif"><b>"Evans, Mark"
<Mark_Evans at maxtor.com&gt;</b> </font>
<br><font size=1 face="sans-serif">Sent by: owner-t10 at t10.org</font>
<p><font size=1 face="sans-serif">09/22/2004 11:50 AM</font>
<td width=59%>
<table width=100%>
<tr>
<td>
<div align=right><font size=1 face="sans-serif">To</font></div>
<td valign=top><font size=1 face="sans-serif">"T10 Reflector"
<t10 at t10.org&gt;</font>
<tr>
<td>
<div align=right><font size=1 face="sans-serif">cc</font></div>
<td valign=top>
<tr>
<td>
<div align=right><font size=1 face="sans-serif">Subject</font></div>
<td valign=top><font size=1 face="sans-serif">RE: TAS and Extended Contingent
Allegiance</font></table>
<br>
<table>
<tr valign=top>
<td>
<td></table>
<br></table>
<br>
<br>
<br><font size=2><tt>* From the T10 Reflector (t10 at t10.org), posted by:<br>
* "Evans, Mark" <Mark_Evans at maxtor.com&gt;<br>
*<br>
Hi Ralph,<br>
<br>
I think that the only option is to change the bit to "obsolete".
&nbsp;If someone requires the TAS functionality, then a new bit should
be assigned.<br>
<br>
Regards,<br>
<br>
Mark Evans<br>
Maxtor Corporation<br>
<br>
 -----Original Message-----<br>
From: &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;owner-t10 at t10.org
[mailto:owner-t10 at t10.org] &nbsp;On Behalf Of Ralph O. Weber<br>
Sent: &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
Tuesday, September 21, 2004 10:47 AM<br>
To: &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
T10 Reflector<br>
Subject: &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
TAS and Extended Contingent Allegiance<br>
<br>
* From the T10 Reflector (t10 at t10.org), posted by:<br>
* "Ralph O. Weber" <roweber at ieee.org&gt;<br>
*<br>
It has been brought to my attention that SPC-1 changed<br>
bit 7 of byte 4 in the Control mode page from EECA (Enable<br>
Extended Contingent Allegiance) to Reserved.<br>
<br>
In SPC-2, the same bit was changed from Reserved to TAS<br>
(Task Aborted Status).<br>
<br>
Apparently, some firmware out there still interprets<br>
Control mode page byte 4 bit 7 to mean Enable Extended<br>
Contingent Allegiance.<br>
<br>
Since it seems likely that lots of other firmware interprets<br>
the same bit as enabling the sending of TASK ABORTED status,<br>
there may be a nasty problem brewing here.<br>
<br>
All the best,<br>
<br>
.Ralph<br>
<br>
*<br>
* For T10 Reflector information, send a message with<br>
* 'info t10' (no quotes) in the message body to majordomo at t10.org<br>
*<br>
* For T10 Reflector information, send a message with<br>
* 'info t10' (no quotes) in the message body to majordomo at t10.org<br>
</tt></font>
<br>
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