Re: regression fixed by using pci=rom

From: Linus Torvalds
Date: Thu May 08 2008 - 21:48:52 EST




On Thu, 8 May 2008, Jesse Barnes wrote:
>
> Hm, yeah in many cases we definitely *do* want to try to get the expansion ROM
> space allocated. But maybe it should be a lower priority than other BARs...
> Gary?

The thing is, a lot of these things have been done this way because not
doing them that way breaks.

We want to allocate expansion ROM space - even if we don't enable it -
because not doing so will screw up bus sizing etc, and can make it
impossible to allocate later.

In general, changing PCI allocation strategy is really _really_ dangerous,
even when it is "right", because it tends to expose a lot of issues where
something worked just because it was perhaps indirectly causing a layout
that worked.

So the reason I immediately reverted this is that it was simply totally
wrong. If somebody cares about multi-node systems, the onus of making
those work should be on *that*, not on old systems that already work.

Ingo, Thomas: I would _seriously_ suggest that you don't consider the x86
PCI setup code to be "x86" code. Because it isn't. Not in that sense. Just
don't take patches to it.

Linus
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