Re: [RFC PATCH] PCI MMCONFIG: add validation against ACPI motherboard resources

[Robert Hancock <hancockr@shaw.ca>]

Jesse Barnes wrote:
> On Tuesday, May 01, 2007, Jesse Barnes wrote:
>>> I'm testing it now on my 965...
>> Bah... nevermind Robert, I see you're doing this already in
>> pci_mmcfg_reject_broken.  I'm about to reboot & test now.
> 
> Ok, I've tested a bit on my 965 (after re-adding my old patch to support 
> it) and the new checks are more complete, but my BIOS still appears to be 
> buggy.
> 
> The extended config space (as defined by the register) is at 0xf0000000 
> (full value is 0xf0000003 indicating 128M enabled).  The ACPI MCFG table 
> has this space reserved according to Robert's new code, but the machine 
> hangs due to the address space aliasing Olivier mentioned awhile back.  I 
> don't have a PCIe card to test with (or any devices that require extended 
> config space that I know of) so I can't really tell if Windows supports 
> PCIe on this platform, but if it does I don't see how it would w/o having 
> a full bridge driver and sophisticated address space allocation builtin.

Windows XP doesn't use MMCONFIG or any extended configuration space. I 
believe Vista is supposed to, though. Not sure how they are handling 
this issue.

> 
> I'm going to try updating my BIOS, but if that doesn't solve this problem, 
> I'm not sure what we can do about it.  Should pci_mmcfg_insert_resources 
> check for conflicts?  Should we just blacklist certain boards?  I can try 
> pinging our BIOS folks about this board to see what was intended, but I'm 
> sure this won't be the only board we have problems with, so we'll need to 
> address it generically somehow.

Can you post what your board has for PNPACPI reserved resources (I 
believe they're in /sys/devices/pnp0/*/resources IIRC, don't have a 
Linux box handy right now). Full dmesg would also be useful, I think it 
dumps out those reservations at boot nowadays..

-- 
Robert Hancock      Saskatoon, SK, Canada
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