Re: pci-disable-decode-of-io-memory-during-bar-sizing.patch

From: Andi Kleen
Date: Tue Oct 30 2007 - 14:51:21 EST



> At that point, almost all the issues with mmconfig just go away, BECAUSE
> NOBODY USES IT, so it doesn't matter if it's broken?

We seem to slowly grow more uses of registers > 256, but yes it's still mostly
non critical stuff.

> The fact is, CONF1 style accesses are just safer, and *work*.
>
> Can we please just do that?

At least for the AMD GART IOMMU I would prefer if that was not done.
It has a pci config space access in a time critical path (flush).
And Family10h supports accessing the northbridge using mmconfig.

I believe the tigon3 driver also does config space access frequently
on some chips.

Also there are still the old x86 Macs where conf1 doesn't work.

-Andi
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