Messages in this thread | | | Date | Sat, 22 Dec 2007 20:40:14 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: [patch] Make MMCONFIG space (extended PCI config space) a driver opt-in issue |
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On Sat, 22 Dec 2007, Jeff Garzik wrote: > > It should be self-evident that mmconfig doesn't work on old hardware, is not > needed on old hardware, should not be turned on for old hardware, and in > general should never disturb old hardware.
.. but it does. How do you figure out when to turn it off?
By "old hardware" I don't mean stuff from the last century, that generally doesn't even *have* MMCONFIG. I mean the stuff you can buy *today*, which will be old by the time people really start _needing_ MMCONFIG.
The fact is, 99% of the hardware you buy *today* has absolutely zero need for extended PCI config access. In fact, I would not be surprised at all if most hardware sold today generally doesn't have *any* devices that even have config registers in the 0x100+ range.
So those are the kinds of machines we want to protect from blowing up. Stuff that isn't sold with Vista, and has never been tested (or where vista does some work-arounds we don't even know about - somebody was mentioning things like looking at the BIOS date etc).
Linus
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