Radeon 9000 Pro corruption problem on PPC when DRI is enabled

[Benjamin Herrenschmidt]

> I can now confirm that this is a mac card (can you even use non-mac
> cards in a mac?). 

Yes if you coerce xf86emu into softbooting them :) Needs a bit of
hacking at best.

> I checked the specs on ATI's website - the non-mac
> cards have a VGA port, something which this thing has not. The lspci
> output does have that "expansion rom" line. It says "disabled" though,
> hmm...

That's normal. There is a ROM, it just doesn't contain an x86 BIOS. It
contains an Open Firmware F-code driver for use by Apple firmware. Such
a ROM doesn't provide the tables generally found in ATI x86 BIOS ROMs
that the driver then uses. (The ATI MacOS driver gets some of those
infos via different means not currently accessible to X.org, including
having a big hard coded table :)

> Well, I'd like to point out that the screen is perfectly usable with DRI
> off, so using those bogus BIOS values can't be messing stuff up too much
> (unless they're only used by the DRI? when UseFBDev is off?). Also, all
> that PLL stuff happens when UseFBDev is on too...

They are used for everything including setting modes when UseFBDev is
not set. And possibly in othrer cases I don't have on top of my mind at
the moment, this driver is a mess :)

Ben.