Radeon 9000 Pro corruption problem on PPC when DRI is enabled

[Roland Scheidegger]

Ari Entlich wrote:
>>>> I could /try/ to look at the code, but I know nothing about Radeon 
>>>> hardware and my C skills aren't quite professional-grade just yet, so
>>>>  I can't promise anything :-).
>>> The attached patch might fix things. Completely untested, I think it
>>> should apply to pretty much any version of radeon_bios.c you can find...
>>>
>> Yeah, ok, I'll try that. God, I love Gentoo :-). Is that the test
>> radeonfb uses?
>>
> 
> Awesome!!! This fixed both the DRI corruption and UseFBDev problems!
> Well, that patch as you sent it didn't fix it (keep reading), but the
> problem has definitely been identified! The check you used to test for
> an x86 BIOS doesn't work
The test is bogus (the 0x14 value is relative to the adress at 0x18, not 
relative to the vbios start). So it wouldn't work.
That said, I don't understand why it would get identified as a x86 bios 
if it isn't, as xf86ReadPciBIOS checks that itself, so in fact there 
shouldn't be any need to put in the same verification again in the 
radeon driver.
There is some debug code in xserver/xorg/hw/xfree86/os-support/bus/Pci.c 
(PRINT_PCI) maybe this would provide some insight what's going on. There 
seems to be absolutely no code difference between 6.8.2 and 7.1 there, 
just as there doesn't seem to be a difference in the radeon driver 
itself wrt to bios reading...

Roland