ibm thinkpad 600, freeze when serial port accessed ...

[Kevin Oberman]

> Date: Sat, 23 Aug 2003 21:33:31 +0000 (GMT)
> From: bruno schwander <bruno at tinkerbox.org>
> Sender: owner-freebsd-mobile at freebsd.org
> 
> anytime I try to access the serial port, the laptop freezes and a reboot
> is needed.
> 
> dmesg output for sio:
> 
> sio0: configured irq 4 not in bitmap of probed irqs 0
> sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0
> sio0: type 8250
> 
> this is on:
> FreeBSD thinkpad 4.8-RELEASE FreeBSD 4.8-RELEASE #2: Tue Aug 19 19:44:37
> GMT 2003     bruno at thinkpad:/usr/obj/usr/src/sys/THINKPAD  i386
> 
> under windows 98 (also installed on that same machine, in an other
> partition) I checked that the serial port is enabled and the infrared
> serial port disabled (with the special thinkpad configuration tool) .
> Windows hardware shows the serial port as irq 4, port 3f8-3ff but who
> knows if that what it really should be. I read in some other port that the
> 'not in bitmap of probed irq' means the port was not detected correctly.
> How should that be configured ? Isn't that serial port part of the support
> chip ?
> 
> Anybody using successfully their serial port on a thinkpad 600, please let
> me know your configuration...  Anybody else with ideas on what to check,
> let me know !

The problem is almost certainly that the serial port is not enabled in
BIOS. The serial port on the 600E is disabled by default as Windows
will enable dynamically, but net change the default in CMOS memory..

The only way to fix this is to use the DOS program "ps2" to enable
the port in BIOS and save it to CMOS memory. (The ThinkPad
Configuration tool will enable it in the running system, but saves
that in the registry and re-enables it with every boot.)

You can boot up Windows and run ps2 in a command window or you can
download a bootable floppy image from the IBM web site. Look for the
DOS configuration utility.

Try 'ps2 ?' and 'ps2 ? ser'.
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634