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

Jesse Barnes
2007-10-31T01:30:43Z

On Tuesday, October 30, 2007 4:59 pm Linus Torvalds wrote:
> Also, there are several devices that don't show up in the MMCFG
> things, or just otherwise get it wrong.
>
> So just take a look at arch/x86/pci/mmconfig-shared.c and look for
> "conf1".
>
> Really. Damn, I'm nervous taking any MMCFG patches that has you as an
> author, if you aren't even aware of these kinds of fundamnetal
> issues. You probably read the standards about how things are
> "supposed" to work, and then just believed them?

We have a few bits of code in there to look at the actual MMCONFIG base
register, which is good since we can sanity check it against the
firmware. However, by itself it's not enough since we may end up using
it even though the BIOS didn't tell us about an overlap that really
does exist. Robert recognized this and added checks to make sure the
values read from the base regs actually matched what the firmware was
telling us in the ACPI tables (at least iirc, it's been awhile since I
looked at the patch).

So don't be too nervous. :)

Jesse