kern/172150: SCSI bus scan on mps(4) spews thousands of lines on console

[Garrett Wollman]

>Number:         172150
>Category:       kern
>Synopsis:       SCSI bus scan on mps(4) spews thousands of lines on console
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Sep 28 23:10:04 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Garrett Wollman
>Release:        FreeBSD 9.0-STABLE amd64
>Organization:
MIT Computer Science & Artificial Intelligence Laboratory
>Environment:
System: FreeBSD nfs-prod-0.csail.mit.edu 9.0-STABLE FreeBSD 9.0-STABLE #7 r237562M: Tue Jun 26 22:14:57 EDT 2012 wollman at xyz.csail.mit.edu:/usr/obj/usr/src/sys/CSAIL amd64

>Description:

Anything that causes a bus scan on mps(4) devices results in many
thousands of lines of junk being spewed to the console, with the
system unresponsive.

The junk looks like this:

(probe719:mps1:0:720:0): INQUIRY. CDB: 12 0 0 0 24 0 
(probe719:mps1:0:720:0): CAM status: Invalid Target ID
(probe719:mps1:0:720:0): Error 22, Unretryable error
(probe720:mps1:0:721:0): INQUIRY. CDB: 12 0 0 0 24 0 
(probe720:mps1:0:721:0): CAM status: Invalid Target ID
(probe720:mps1:0:721:0): Error 22, Unretryable error
(probe721:mps1:0:722:0): INQUIRY. CDB: 12 0 0 0 24 0 
(probe721:mps1:0:722:0): CAM status: Invalid Target ID
(probe721:mps1:0:722:0): Error 22, Unretryable error
(probe722:mps1:0:723:0): INQUIRY. CDB: 12 0 0 0 24 0 
(probe722:mps1:0:723:0): CAM status: Invalid Target ID
(probe722:mps1:0:723:0): Error 22, Unretryable error
(probe723:mps1:0:724:0): INQUIRY. CDB: 12 0 0 0 24 0 
(probe723:mps1:0:724:0): CAM status: Invalid Target ID
(probe723:mps1:0:724:0): Error 22, Unretryable error
(probe724:mps1:0:725:0): INQUIRY. CDB: 12 0 0 0 24 0 
(probe724:mps1:0:725:0): CAM status: Invalid Target ID
(probe724:mps1:0:725:0): Error 22, Unretryable error
(probe725:mps1:0:726:0): INQUIRY. CDB: 12 0 0 0 24 0 
(probe725:mps1:0:726:0): CAM status: Invalid Target ID
(probe725:mps1:0:726:0): Error 22, Unretryable error
(probe726:mps1:0:727:0): INQUIRY. CDB: 12 0 0 0 24 0 
(probe726:mps1:0:727:0): CAM status: Invalid Target ID
(probe726:mps1:0:727:0): Error 22, Unretryable error
(probe727:mps1:0:728:0): INQUIRY. CDB: 12 0 0 0 24 0 
(probe727:mps1:0:728:0): CAM status: Invalid Target ID

This sequence is repeated many times (I haven't tried to count) until
eventually it gives up.

>How-To-Repeat:

Build a fileserver with a pair of SAS2116 cards.  Plug something in.
Wait fifteen minutes for the new device to finally get attached.

>Fix:

1) Don't output these messages unless debugging is turned on.
2) If CAM already knows that they target ID is invalid, then it should
terminate the probe for that target rather than retrying a huge number
of times.

>Release-Note:
>Audit-Trail:
>Unformatted: