Re: [PATCH] x86/pci: do assign root bus res if _CRS is used

Yinghai Lu
2009-04-28T02:07:01Z

On Mon, Apr 27, 2009 at 3:24 PM, Bjorn Helgaas <bjorn.helgaas@hp.com> wrote:
> On Monday 27 April 2009 03:00:16 pm Yinghai Lu wrote:
>> On Mon, Apr 27, 2009 at 1:39 PM, Bjorn Helgaas <bjorn.helgaas@hp.com> wrote:
>> >> other system may have broken _CRS.
>> >
>> > Do you have examples of problems here, or are you just worried that
>> > there *may* be problems?
>> one system with three chains... with pci=use_crs
>> [    9.365669] pci_bus 0000:00: resource 0 io:  [0x00-0x3af]
>> [    9.371065] pci_bus 0000:00: resource 1 io:  [0x3e0-0xcf7]
>> [    9.376551] pci_bus 0000:00: resource 2 io:  [0x3b0-0x3bb]
>> [    9.382028] pci_bus 0000:00: resource 3 io:  [0x3c0-0x3df]
>> [    9.387513] pci_bus 0000:00: resource 4 io:  [0xd00-0xefff]
>> [    9.393077] pci_bus 0000:00: resource 5 mem: [0x0a0000-0x0bffff]
>> [    9.399084] pci_bus 0000:00: resource 6 mem: [0x0d0000-0x0dffff]
>> [    9.405089] pci_bus 0000:00: resource 7 mem: [0xdd000000-0xdfffffff]
>> [    9.505332] pci_bus 0000:40: resource 0 io:  [0x5000-0x8fff]
>> [    9.510991] pci_bus 0000:40: resource 1 mem: [0xdb000000-0xdcffffff]
>> [    9.553378] pci_bus 0000:80: resource 0 io:  [0x1000-0x4fff]
>> [    9.559036] pci_bus 0000:80: resource 1 mem: [0xda000000-0xdaffffff]
>>
>> without that: amd_bus.c will read that from pci conf space
>> [    9.310965] pci_bus 0000:00: resource 0 io:  [0x9000-0xefff]
>> [    9.316621] pci_bus 0000:00: resource 1 io:  [0x00-0xfff]
>> [    9.322020] pci_bus 0000:00: resource 2 mem: [0xdd000000-0xdfffffff]
>> [    9.328373] pci_bus 0000:00: resource 3 mem: [0x0a0000-0x0bffff]
>> [    9.334378] pci_bus 0000:00: resource 4 mem: [0xc0000000-0xd9ffffff]
>> [    9.340731] pci_bus 0000:00: resource 5 mem: [0xf0000000-0xffffffff]
>> [    9.347084] pci_bus 0000:00: resource 6 mem: [0x840000000-0xfcffffffff]
>> [    9.444440] pci_bus 0000:40: resource 0 io:  [0x5000-0x8fff]
>> [    9.450099] pci_bus 0000:40: resource 1 io:  [0xf000-0xffff]
>> [    9.455757] pci_bus 0000:40: resource 2 mem: [0xdb000000-0xdcffffff]
>> [    9.498118] pci_bus 0000:80: resource 0 io:  [0x1000-0x4fff]
>> [    9.503777] pci_bus 0000:80: resource 1 mem: [0xda000000-0xdaffffff]
>
> It's interesting that many of the differences involve the legacy
> VGA I/O ports in the 0x3b0-0x3df range.  My guess is that the AMD
> chipset has special routing for those ranges.  If it didn't, it
> would be difficult to support VGA devices under the other two
> root bridges.  Maybe that VGA routing doesn't show up in the
> bridge's PCI config space.  Can you tell from the ASL whether the
> root bridge _SRS/_PRS/_CRS methods handle the VGA ranges specially?
>
> One of the differences is that PCI config space shows a 64-bit region
> (bus 0000:00 mem 0x840000000-0xfcffffffff) that doesn't show up in
> the _CRS info.  But the _CRS parsing depends on acpi_resource_to_address64(),
> which doesn't know about the ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64
> descriptors added in ACPI 3.0.  So this difference could be a result
> of that Linux bug.  It'd be interesting to see whether the test patch
> below makes a difference.
will check it.
>
> The PCI config space region 0xf0000000-0xffffffff, also on bus 0000:00,
> looks suspicious to me.  I thought that area contained a bunch of
> BIOS-y things like reset vectors and local APICs.

in the amd_bus.c, will put left over resource to def HT chain.

YH