Re: BX chipsets and 2.0.34pre

Phil's Kernel Account (
Wed, 20 May 1998 22:38:04 -0400 (EDT)

On Wed, 20 May 1998, Trevor Johnson wrote:

#> Intel seem to have cunningly arranged that the Cyrix check stuff using I/O
#> 0x22/0x23 happens to completely screw the settings on a BX motherboard, making
#> 2.0.34pre* do weird things.
#> I'll release another prepatch tomorrow (UK time) that will drop the Cyrix
#> probing. Hopefully that will sort out the remaining 2.0.34 bug reports on
#> the IDE, irq loss and weird crashes with BX
#How about something like
#if (cyrix_present()) {
##ifdef CONFIG_PCI
# if (!check_for_bx()) {
# do_cyrix_probe();
# ...
# } else {
# printk("Cyrix CPU and Intel BX chip set detected, not
#probing for Cyrix problem\n");
# printk("Cyrix CPU detected but PCI not configured, can't check
#for Intel BX so won't probe for Cyrix problem\n");

In THEORY, possible. However, you've got it a little screwed up. We need
to keep this in mind;

If you've got a Cyrix, you don't have BX. If you've got BX, you don't have
Cyrix. Why? Because BX is pII *ONLY*. What I would LIKE to do, AFTER I get
all my docs and boards to reverse eng, er, play with ;), is make a nice
pretty workaround for the mutual exclusions. If it sees BX, no Cyrix
stuff. If it sees Cyrix, no BX stuff. I can't remember the order offhand
(I'm almost POSITIVE it's CPU->PCI->Rest, but do NOT quote me on that;),
and I don't have the docs, so I'm not going to submit any fixes yet.

However, I'd say go ahead and apply that, with some small modifications.
I'm gonna simplify this, because I can't just spout source. :)

if Cyrix present
do NOT test for BX
if AMD present
do NOT test for BX
if BX present
do NOT test for Cyrix
printk("BX Chipset present; Not probing for non-Intel CPUs.\n")

Why add AMD? AMD doesn't have their Slot1 processor out yet, so it's silly
to probe for AMD stuff on a BX chipset right now. And it could cause
problems. So let's not risk it. ;P

#? Users who don't like the warnings can just look at the pretty penguin.

heheheheheheheheheheheh.. gooooooooo tux. :)

-Phil R. Jaenke ( /
TheGuyInCharge(tm), Ketyra Designs - We get paid to break stuff :)
Linux pkrea.ketyra.INT 2.0.33 #15 Sat Apr 18 00:40:21 EDT 1998 i586
Linux 2.1.98 #15 Fri May 1 18:21:00 EDT 1998 i586
- Linus says for 'brave people only.' I say 'keep a backup.' - :)
! I reserve the right to bill spammers for my time and disk space !

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