[MiNT] Qfunk bug found? (fwd)

[kellis <kellis@leading.net>]

---------- Forwarded message ----------
Date: Sat, 15 May 1999 23:03:23 +0000
From: kellis <kellis@leading.net>
To: MiNT mailing list <mint@fishpool.com>
Subject: Qfunk bug found?

Hello people. I have some interesting news for you all.

I was playing around with MiNTsetter CPU caches.

Then I noticed that my screen was all messed up If the cache:
"Data Write Allocate" was off.

The color of some window content were reversed, the font changed, not
redrawn correctly etc.
Very bad, but still the computer was up.
Then I switch the cache back on, And everythng is back to normal.

This only happens wth the Data write allocate cache.

(I have a falcon wth ct2 with nvdi 5.0 an latest mint official)

My system is stable and I can not complain at all.

But then, I was talking to Lonny Pursel (airc developer) who has a TT with
nvdi 5.1, crazydot g.card and latest official miint kernel.
I asked him to see if the vdi would be messed up if this cache was off.

He tries so, and boom, big freeze.

Reboot, and tries again, same freeze.

So, Here are my guessings:

1) MiNTsetter hasn't implemented the caches correctly.

2) That qfunk, and some other people having problem with MiNT latests,
have an ACC, TSR or whatever tool that set this cache OFF.
I do know that some boot selector for example mess with some caches, or
whatever, doesn't matter. The fact that by default these people have some
caches OFF. 
3) no matter what, The kernal shouldn't freeze like that if I set this
cache to OFF, or showing serious VDI problems.


People, Please try to mess with the CPU caches with MiNTsetter (3.9) and
latest Official Kernel.
To be sure that it is not MiNTsetter faults, Someone (draco?) would write
a 10 lines C program to switch this cache off. And lets all try that out.

I seriously think that I found something here important.

Thanks