Subject: port-i386/26721: IBM PS/2 + MCA 2.0_BETA kernels hang at fdc0 message
To: None <>
From: at <,>
List: netbsd-bugs
Date: 08/19/2004 16:48:37
>Number:         26721
>Category:       port-i386
>Synopsis:       IBM PS/2 + MCA 2.0_BETA kernels hang at fdc0 message
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Aug 19 19:16:00 UTC 2004
>Originator:     Dave Barnes
>Release:        2.0_BETA
Consult Engr
System is IBM PS/2 50z with Reply PowerBoard - 486 class CPU upgrade.  CPU is AMD 5x86 (Kingston TurboChip).  Floppy interface is Intel 82078.

When booting a 2.0_BETA kernel, GENERIC, INSTALL, or INSTALL_PS2, system hangs immediately after fdc0 message appears on console.  No fd at fdc0 messages appear.  Custom 2.0_BETA kernel without floppy support boots normally - just no floppy access. 1.6 and 1.6.2 kernels boot correctly and floppy drive is usable.  

CPU proceeds normally until spl0 in function cpu_configure of file src/sys/arch/i386/i386/autoconf.c enables interrupts.  Then CPU continually services function fdcintr of file src/sys/dev/isa/fd.c .

Further debugging:
Function fdcattach of file fd.c runs and puts function fdcfinishattach on interrupt queue via function config_interrupts.  Function fdcfinishattach is never called. 

As soon as interrupts are enabled system hangs servicing irq 6 (floppy interrupt - function fdcintr) even though function fdc_isa_attach in file src/sys/dev/isa/fdc_isa.c has IPL_BIO set in call to isa_intr_establish.  
Try to boot 2.0_BETA on a Reply PowerBoard or Reply TurboBoard.   (I don't have another PS/2 type system to test. The Reply TurboBoard is the 386/486slc version of the motherboard upgrade.)
Unknown - It should work as it works on other i386 systems.  Some subtle / obscure difference in Intel 82078 or PS/2 Microchannel architecture that only affects NetBSD 2.0_BETA?