Messages in this thread | | | Date | Wed, 11 Apr 2012 00:05:34 +0800 | From | Jiang Liu <> | Subject | Re: [PATCH 2/2] PCI, ACPI, x86: update MMCFG information when hot-plugging PCI host bridges |
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On 04/10/2012 11:47 PM, Yinghai Lu wrote: > On Tue, Apr 10, 2012 at 3:32 AM, Kenji Kaneshige > <kaneshige.kenji@jp.fujitsu.com> wrote: >> Additionally, I think there is a remaining issue even if we change >> this check like below. >> >> >> if (!!(pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF)) >> return 0; >> >> I think this check has an assumption that system has at least one >> MCFG table entry and it has been initialized before >> acpi_pci_root_add() is called. I think this doesn't work on the >> system that doesn't have MCFG and all the pci root bridge have >> _CBA (that is, all host bridges are hot-pluggable and BIOS is >> implemented in the way PCI FW spec defines). As a result, MMCONFIG >> would never be enabled on such systems. Could you double check this? > > You are right. > > We can just remove that checking. > > But wonder if current x86_64 system support that. > All peer root buses can be physically removed ? It's theoretically possible that BIOS doesn't provide MMCFG or _CBA for the legacy (non-removable bus 0) host bridge.
> > Thanks > > Yinghai
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