Subject: port-pmax/3776: cpuspeed variable on pmax 5000/260 too small
To: None <gnats-bugs@gnats.netbsd.org>
From: Simon Burge <simonb@telstra.com.au>
List: netbsd-bugs
Date: 06/23/1997 13:27:14
>Number:         3776
>Category:       port-pmax
>Synopsis:       cpuspeed variable on pmax 5000/260 too small
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    gnats-admin (GNATS administrator)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jun 22 20:35:01 1997
>Last-Modified:
>Originator:     Simon Burge
>Organization:
	Telstra Corp, Australia
>Release:        NetBSD-current 970623
>Environment:
System: NetBSD vlad 1.2G NetBSD 1.2G (MONA) #0: Mon Jun 23 11:15:24 EST 1997 simonb@mona:/usr/src/sys-970623/arch/pmax/compile/MONA pmax

>Description:
	The cpuspeed variable in arch/pmax/pmax/autoconf.c has the
	value 30 with is too small on the faster DECstations.  One
	obvious side effect of this is that when typing on a serial
	console characters repeat unexpectantly because the DELAY(2)
	in the scc code is much shorter than the 2us that the chip
	takes to settle.
>How-To-Repeat:
	Log on to the console of a 5000/260 and type :-)
>Fix:
	There's two different fixes:

	  Change the value of cpuspeed in autoconf.c to a larger
	  value if on an R4000 or R4400 CPU.

	or

	  Actually calculate the clock speed and use that.  This
	  code could also be used to determine whether the machine
	  is a 20, 25 or 33 MHz CPU for some machines.

	The first is trivial, the second a bit harder...
>Audit-Trail:
>Unformatted: