SPL disparity errors counter conflict

[Kevin_Marks at Dell.com]

Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r0904271_f.htm">HTML-formatted message</a>

I think of them more as two counters, counting the same thing, one
wrapping, one saturating. This also applies to the other 3 original
counters.
Kevin
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of Penokie,
George
Sent: Monday, April 27, 2009 8:26 AM
To: Elliott, Robert (Server Storage); t10 at t10.org
Subject: RE: SPL disparity errors counter conflict
How is it possible for one counter to have two diametrically opposed
characteristics? A single counter cannot be both wrapping and saturating
at the same time. 
Bye for now, 
George Penokie 
LSI Corporation 
3033 41st St. NW 
Suite 100 
Rochester, MN 55901 
507-328-9017 
george.penokie at lsi.com 
________________________________
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of Elliott,
Robert (Server Storage)
Sent: Tuesday, April 14, 2009 8:32 PM
To: t10 at t10.org
Subject: RE: SPL disparity errors counter conflict
Both.  
When reported via the old REPORT PHY ERROR LOG function, they are always
saturating values.  They can be cleared with the PHY CONTROL function
CLEAR ERROR LOG phy operation, but that's not multi-initiator friendly.
When reported via the REPORT PHY EVENT LIST function (if those events
have been selected as sources - there are many other sources also
available), they are wrapping values.  These are multi-initiator
friendly.
________________________________
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of Penokie,
George
Sent: Tuesday, April 14, 2009 6:45 PM
To: t10 at t10.org
Subject: SPL disparity errors counter conflict
The running disparity errors counter in SPL (and SAS-2) in two places is
called out as a saturating counter and one place as a wrapping counter.
(see below for the wording) Note that WC stands for wrapping counter.
So which is it. It appears that the specification in table 37 (SPL r1)
is not correct, any comments.
4.11 Phy events
Phys shall count the following events using saturating counters and
report them in the Protocol-Specific Port log page (see 9.2.8.1) and/or
the SMP REPORT PHY ERROR LOG function (see 9.4.3.11):
a) invalid dwords received;
b) dwords received with running disparity errors;
c) loss of dword synchronization; and
d) phy reset problems.
Table 37 - PHY EVENT SOURCE field (part 1 of 4)
02h Running disparity error count	     WC        Number of dwords
containing running disparity errors (see 5.3.5) that have been received
outside of phy reset sequences
9.4.3.11 REPORT PHY ERROR LOG function
The RUNNING DISPARITY ERROR COUNT field indicates the number of dwords
containing running disparity errors (see 5.3.5) that have been received
outside of phy reset sequences. The count shall stop at the maximum
value. The RUNNING DISPARITY ERROR COUNT field is set to a
vendor-specific value after power on.
Bye for now, 
George Penokie
LSI Corporation 
3033 41st St. NW 
Suite 100 
Rochester, MN 55901
507-328-9017 
george.penokie at lsi.com