From andrewb@cs.cmu.edu  Mon Feb 21 02:01:00 2005
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Date: Sun, 20 Feb 2005 20:58:35 EST
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Cc: pbelle@fisica.ufjf.br
Subject:

>Number:         77822
>Category:       kern
>Synopsis:       (summary missing)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          closed
>Quarter:        
>Keywords:       
>Date-Required:  
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Feb 21 02:10:10 GMT 2005
>Closed-Date:    Fri Apr 01 06:34:27 GMT 2005
>Last-Modified:  Fri Apr 01 06:34:27 GMT 2005
>Originator:     
>Release:        
>Organization:
>Environment:
>Description:
 Hi,
 
 I've been having the same problem with FreeBSD 5.3 and my BT-958.
 
 It looks like the drive or the BT-958 is returning zero for its
 "period factor" for whatever reason.  The kernel code in
 src/sys/cam/scsi/scsi_all.c doesn't check for this (probably invalid)
 case and proceeds to use zero as a divisor at line 2329.
 
 Applying the following patch at line 2302 heads off the divide
 by zero and assumes that a "period factor" of zero means
 20 mbit/sec SCSI:
 
 2302c2302,2303
 <       { 0x0c, 5000 }  /* FAST-20 */
 ---
 >       { 0x0c, 5000 }, /* FAST-20 */
 >       { 0x00, 5000 }  /* FAST-20 */
 
 This enables the drive to come up normally.
 
 I've been using this patch on my home system for about a week
 now, with no apparent problems (but use at your own risk!).
 I don't know whether it's safe to assume FAST-20 when the
 BT-958 returns zero for its "period factor", but I think
 that the kernel should at least be checking for a zero divisor
 and reporting a device error instead of bringing the whole
 system down on a zero divide fault.
 
 Please let me know if any additional information would be helpful.
 
 Thanks,
 
 Andrew Bernard
 
>How-To-Repeat:
>Fix:
>Release-Note:
>Audit-Trail:
Responsible-Changed-From-To: gnats-admin->freebsd-bugs 
Responsible-Changed-By: linimon 
Responsible-Changed-When: Mon Feb 21 13:46:05 GMT 2005 
Responsible-Changed-Why:  
You've managed to do a followup while supressing the Summary: line, 
which is what GNATS uses to assign new text as followup, so neither 
GNATS (nor I for that matter) have any idea what PR the text in 
this PR is supposed to be a followup to.  Please reply with that 
information and I'll try to fix it up.  Thanks. 

http://www.freebsd.org/cgi/query-pr.cgi?pr=77822 
State-Changed-From-To: open->closed 
State-Changed-By: linimon 
State-Changed-When: Fri Apr 1 06:32:49 GMT 2005 
State-Changed-Why:  
Feedback timeout.  With the Synopsis (Subject:) line suppressed, GNATS 
is unable to figure out to which PR the followup is supposed to apply. 
I could not figure it out myself and the submitter did not respond to 
an emailed request. 

http://www.freebsd.org/cgi/query-pr.cgi?pr=77822 
>Unformatted:
