Re: PCI bridge range sizing bug

[Rik van Riel <riel@redhat.com>]

Jesse Barnes wrote:
> On Friday, April 20, 2007 11:28 am Linus Torvalds wrote:
>> On Fri, 20 Apr 2007, Jesse Barnes wrote:
>>> Sounds good, hopefully reassigning the bridge resources won't cause
>>> too much trouble.  Do you have time to hack this up?  If not, I
>>> could give it a try, as long as ajax is willing to test...
>> Actually, I would suggest we not do it automatically (because the
>> need for it is just so low, and the downsides are potentially huge -
>> there are just too many resources that are "hidden" from us through
>> ACPI tricks and having hardware that doesn't actually expose their
>> PCI resources fully through the normal PCI resource setup).
> 
> Yeah, that's probably prudent.  OTOH we should probably let the user 
> know in no uncertain terms that some of the stuff behind one of their 
> bridges will be inaccessible.

Something like that would have made it a lot more obvious
why my Matrox PCIe x1 video card will not work in my Dell
9150, while a PCI video card does work.

The PCI video card directly sits on the bus, and gets its
resources assigned by the BIOS.

The PCIe video card turned out to be a PCIe to AGP bridge,
and the BIOS did not assign the needed PCI resources, making
the system crash when I started X.

X seemed to have some trouble reading the ROM, too...

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