On Mon, Mar 30, 2015 at 3:54 PM, David Ahern <david.ahern@oracle.com> wrote:
> On 3/29/15 2:07 PM, Yinghai Lu wrote:
>>
>> [  286.647560] PCI: scan_bus[/pci@300/pci@1/pci@0/pci@6] bus no 8
>> [  286.921232] PCI: Claiming 0000:00:01.0: Resource 15:
>> 0000800100000000..00008004afffffff [220c]
>> [  287.229190] PCI: Claiming 0000:01:00.0: Resource 15:
>> 0000800100000000..00008004afffffff [220c]
>> [  287.533428] PCI: Claiming 0000:02:04.0: Resource 15:
>> 0000800100000000..000080012fffffff [220c]
>> [  288.149831] PCI: Claiming 0000:03:00.0: Resource 15:
>> 0000800100000000..000080012fffffff [220c]
>> [  288.252466] PCI: Claiming 0000:04:06.0: Resource 14:
>> 0000800100000000..000080010fffffff [220c]
>> [  288.867196] PCI: Claiming 0000:05:00.0: Resource 0:
>> 0000800100000000..0000800100001fff [204]
>> [  288.968221] pci 0000:05:00.0: can't claim BAR 0 [mem
>> 0x800100000000-0x800100001fff]: no compatible bridge window
>>
>> the bridge resource has IORESOURCE_PREFETCH, but the device doesn't have
>> that.
>
> # lspci -vvxxx -s 0000:05:00.0
> 0000:05:00.0 USB controller: Renesas Technology Corp. uPD720201 USB 3.0 Host
> Controller (rev 03) (prog-if 30 [XHCI])
>         Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx+
>         Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
> <TAbort- <MAbort- >SERR- <PERR- INTx-
>         Latency: 0, Cache Line Size: 64 bytes
>         Interrupt: pin A routed to IRQ 00000004
>         Region 0: Memory at 100000000 (64-bit, non-prefetchable) [size=8K]

ok, that is really non-pref mmio 64bit.
We can workaround the problem by honoring firmware setting, according
to https://www.pcisig.com/specifications/pciexpress/base2/PCIe_Base_r2.1_Errata_08Jun10.pdf
page 13

Please check attached updated patches that should fix the regression
and kill those "no compatible window" warnings.

Thanks

Yinghai