Re: [discuss] Re: 2.6.19-rc4: known unfixed regressions (v3)

[Andi Kleen <ak@suse.de>]

On Tuesday 07 November 2006 18:11, Matthew Wilcox wrote:
> On Wed, Nov 08, 2006 at 12:57:03AM +0800, Jeff Chua wrote:
> > 2) this fails ...
> >
> > e0000000-efffffff : 0000:00:02.0
> > f0000000-ffffffff : PCI MMCONFIG 0
> >    fed00000-fed003ff : HPET 0
>
> Heh, no kidding ...
>
>                 num_buses = pci_mmcfg_config[i].end_bus_number -
>                     pci_mmcfg_config[i].start_bus_number + 1;
>                 res->start = pci_mmcfg_config[i].base_address;
>                 res->end = res->start + (num_buses << 20) - 1;
>                 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
>                 insert_resource(&iomem_resource, res);
>
> So if we have 256 busses assigned, then we request 256MB and, well,
> there's no room for anyone else.  This code was added by Andi in commit
> de09bddb9d6f96785be470c832b881e6d72d589f
>
> Hopefully he'll have a good idea how to restrict it.  Given your "working"
> resource map, it seems like it should be limited to 16MB (and thus 16
> busses). But how to figure that out?


ACPI knows the number of busses.

Just need to get the information there, which is a ordering issue
(normally MCFG initialization is before this is known I think)

Len, ACPI folks, any ideas how to fix this cleanly?

-Andi