Subject: port-i386/4565: Accessing /dev/tty01 after apm sleep hangs machine.
To: None <>
From: R. C. Dowdeswell <>
List: netbsd-bugs
Date: 11/23/1997 05:44:26
>Number:         4565
>Category:       port-i386
>Synopsis:       Accessing /dev/tty01 after apm sleep hangs machine.
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    gnats-admin (GNATS administrator)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Nov 23 02:50:01 1997
>Originator:     R. C. Dowdeswell
	The Fall of Imrryr
>Release:        1.3_ALPHA
Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.  All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993
    The Regents of the University of California.  All rights reserved.

NetBSD 1.3_ALPHA (KINSLAYER) #0: Wed Nov 12 12:21:11 PST 1997
cpu0: family 4 model 3 step 5
cpu0: Intel 486DX2 (486-class)
real mem  = 20836352
avail mem = 17989632
using 279 buffers containing 1142784 bytes of memory
mainbus0 (root)
isa0 at mainbus0
com0 at isa0 port 0x3f8-0x3ff irq 4: ns8250 or ns16450, no fifo
lpt0 at isa0 port 0x378-0x37b irq 7
wdc0 at isa0 port 0x1f0-0x1f7 irq 14
wd0 at wdc0 drive 0: <TOSHIBA MK2124FC>
wd0: 124MB, 934 cyl, 16 head, 17 sec, 512 bytes/sec
wd0: using 1-sector 16-bit pio transfers, chs addressing
npx0 at isa0 port 0xf0-0xff: using exception 16
vt0 at isa0 port 0x60-0x6f irq 1
vt0: generic, 80 col, color, 8 scr, mf2-kbd, [R3.32]
pms0 at vt0 irq 12
vt0: console
fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec
pcic0 at isa0 port 0x3e0-0x3e1 iomem 0xd0000-0xd3fff: using irq 3
pcic0: controller 0 (Intel 82365SL Revision 1) has socket A only
pcmcia0 at pcic0 controller 0 socket 0
IBM, w95 Home and Away Credit Card , Version 001, Card Assy Part Number - 10H4706 (manufacturer 0xa4, product 0x2e) function 0 not configured
com1 at pcmcia0 function 1 port 0x3e8-0x3ef: ns16550a, working fifo
pcmcia0: card irq 5
apm0 at mainbus0: Power Management spec V1.0 (BIOS mgmt disabled)
apm0: A/C state: on
apm0: battery charge state:charging
biomask 4040 netmask 4040 ttymask 50ca
boot device: wd0
root on wd0a dumps on wd0b
root file system type: ffs


Accessing /dev/tty01 after the machine has been sleeping hangs the
machine completely.  Not even the kernel debugger wants to work...
So a more complete description is a bit difficult.  Unfortunately,
I do not have the kernel source on this laptop, and it will be a
while before I can get anything like that...

$ su
# zzz
[ a bit of screen flicker, and then its off ]
[ turn it back on ]
[ a bit more screen flicker... ]
# cu -9600 -l /dev/tty01
[ Machine hangs, will not even respond to ctl-alt-esc ]

Also, these lines work in the place of cu -9600...:
# </dev/tty01
# >/dev/tty01

And I'd imagine that anything that twiddles /dev/tty01.


Not sure, the only workaround that I have is to reboot the machine
directly before trying to use the modem if it has slept since the
last reboot.