port-sparc/48795: msiiep_timer.c calibration broken?

[martin%NetBSD.org@localhost]

>Number:         48795
>Category:       port-sparc
>Synopsis:       msiiep_timer.c calibration broken?
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-sparc-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri May 09 09:30:00 +0000 2014
>Originator:     Martin Husemann
>Release:        NetBSD 6.99.41
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD krups.duskware.de 6.99.41 NetBSD 6.99.41 (MP3) #1: Fri May 9 
09:44:23 CEST 2014 
martin%night-owl.duskware.de@localhost:/usr/src/sys/arch/sparc/compile/MP3 sparc
Architecture: sparc
Machine: sparc
>Description:

My Krups has big trouble keeping its time, despite nptd:

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
+ns.duskware.de  199.102.46.73    2 u   29   64  377   43.498  -5528.5 852.789

This was after about 20 minutes, after runing ntpdate and starting ntpd
fresh w/o drift file.

Other sparc (Sparc LX and SS20) machines can sync closely to the same
ntpd server.

I wonder if it is related to timer delay miscalculation:

cpu0 at mainbus0: MB86904 @ 100  MHz, on-chip FPU
cpu0: 16K instruction (32 b/l), 8K data (16 b/l): cache enabled
msiiep0 at mainbus0 addr 0x300c0000
timer0 at msiiep0: delay constant 47

>How-To-Repeat:

Boot a krups and watch the clock wander off.

>Fix:
n/a