In sci.electronics.repair The Real Bev wrote:
I'm sorry, I should have said Radeon instead of nouveau. It's
definitely the Radeon driver.

OK.

The dmesg lines for the two cards are substantially different. For
the card that does not come up readable I don't see any error message,
except for this possibility: "Radeon 0000:01:00.0: registered panic
notifier." That's the only thing that looks like it doesn't belong.

I don't know exactly what that is, but it doesn't *sound* like a big
deal.

When I start X there are numerous repeated sequences of a ~40-line
block that begins with 'GPU lockup CP stall for more than 10000 ms'.
In the last block it ultimately says 'GPU reset succeeded trying to
resume'. There are no lines like this when X starts normally with
the working graphics card.

Hey... you found a difference! I don't know how to *fix* that
particular error, but I think it is a symptom of your problem.

I'm really hoping that somebody else has run into this problem -- and
solved it.

The X.org page for the Radeon driver
http://www.x.org/wiki/RadeonFeature/#index9h2
says bugs can be filed at http://bugs.freedesktop.org/ . It might be
worth a search there to see if anyone else has reported it. If not,
report it yourself.

The X.org page also lists the kernel module parameters at
http://www.x.org/wiki/RadeonFeature/#index4h2
and shows how to check the current values. Perhaps changing one of
those will help, although it may mean a lot of rebooting. (I'm not
sure if you can remove and reinsert the radeon module when you're only
running on a text console, or not.)

In its defense, it doesn't say 'linux compatible' on the box.

I usually ignore that, because it often means "we tested it on one
specific 4-year-old distro with propietary drivers and it kind of
worked". Googling is a much better plan, but it does kind of fall down
with brand new hardware.

Matt Roberds