Re: regression fixed by using pci=rom

[Linus Torvalds <torvalds@linux-foundation.org>]

On Fri, 9 May 2008, Gary Hade wrote:
> 
> Ingo, Would you (or others listening to this discussion) know
> exactly what Windows does with respect to BIOS unassigned
> expansion ROMs?

Nobody really seems to know what windows does for *any* resources. And it 
probably depends on windows version too, and on detailed chipset issues 
(ie does Windows do the same thing as Linux wrt transparent bridges that 
still have bus translation resources set up?).

So the "try to do what Windows does" is something we strive for in 
particular cases, but it's not an absolute thing, and probably can never 
even be that in theory. It's more a guideline, especially when we don't 
know which particular choice is better and both seem otherwise equally 
good.

But "doesn't work" always trumps "that's what windows does". Because even 
if something works under Windows, sometimes Linux drivers simply then act 
differently (ie they may use PIO vs MMIO, or in the case of graphics they 
may need ROMs for re-POST'ing while a windows driver is written by the 
chipset vendor and DTRT without even looking at the BIOS tables)

			Linus