Radeon X700 Mobility: [mi] EQ overflowing ... server lockup

[Daniel]

Hi all. I've been on the 'bleeding edge' ( git ) of mesa, xserver,
xf86-video-ati & friends for the past year or so ( on Gentoo ). I've got
a Turion ( AMD64 ) processor ( running in 64-bit mode ), and a Radeon
X700 Mobility.

I updated everything about a week ago, and couldn't get into X at all -
it locked my system hard and I had to power off ( magic SysRq keys
didn't work ).

I was going to move to Ubuntu when 8.10 came out, but since I had seemed
to have broken my Gentoo system beyond my ability to repair it ( other
than going back to xserver-1.4 ), I thought I'd try out a Ubuntu 8.10
beta release. Things didn't go so well ...

It's using xserver-1.5 and mesa-7.1 ( sorry I don't know what version of
xf86-video-ati ). I got into X the 1st 2 or 3 times with no problems,
but would get lockups after the 1st 10 minutes or so. It looked like X
was segfaulting and in the process of dropping back to the console, I'd
get a corrupted display, as per my previous report ( bits of screen
overlayed in different parts of the screen, and fading from one colour
to another over time ... see my previous report for slightly more
details ).

The only time I managed to get into X and check out
my /var/log/Xorg.log.old, it had a whole heap of this at the end:

[mi] EQ overflowing. The server is probably stuck in an infinite loop

Now ( without having changed anything ), I'm only getting lockups on
entering X, exactly the same as I was on Gentoo. X gets to the point of
showing the crosshair cursor, but before the stipple effect, and doesn't
do anything. I can move the cursor, but *very* slowly. Can't SysRq.
Can't drop to a console. Can't CTRL-ALT-DEL to reboot. Have to power
off.

I was using Ubuntu's generic xorg.conf, which is remarkably small and
must make X detect everything. On Gentoo I had a much longer xorg.conf,
and it wasn't detecting anything ( so it's not the detection stuff
that's crashing ). The only change I made to Ubuntu's xorg.conf was to
enable EXA - admittedly things went sour *after* this, but I haven't
been able to switch back to XAA to test ( how do you stop Ubuntu from
booting straight into X? )

So anyway, something is seriously borked, at least on my Radeon X700
Mobility.

Dan