Re: [PATCH 4/4] ACPI PCI slot detection driver

[Kenji Kaneshige]

Kristen Carlson Accardi wrote:
> On Tue, 11 Mar 2008 22:10:40 +0900
> Kenji Kaneshige <kaneshige.kenji@xxxxxxxxxxxxxx> wrote:
>
> > Hi Alex-san,
> >
> > I tried your patches, and I have two comments. I want 1) to be fixed
> > before merge to Greg's tree (or linux-next?), at least.
>
> yes, we will not merge these patches without your ack.
>
> >  1) I checked ACPI spec again and again, but I could not find any
> >     reason to add Fujitsu servers to quirks list. So I'd like you to
> >     add HP servers to the quirks list. I'll send the following patches
> >     followed by this e-mail.
>
> I have followed up with a question on this on another thread, so I'll
> skip to #2...
> <snip>
>
> >  2) The ACPI PCI slot detection driver would change the slot names of
> >     some hotplug drivers (at least I checked shpchp and pciehp). And
> >     the name of slots are depending on the order of driver loading.
> >     For example, on my system which has several SHPCHP slots and
> >     PCIEHP slots, the name of PCIEHP slots are changed as
> >     follows. Please note that PCIEHP based slots are 0034_0027 and
> >     0032_0026, and others are SHPCHP based slots.
> >
> >     - Without ACPI PCI slot detection driver
> >       # ls /sys/bus/pci/slots/
> >       0009_0016  0014_0018  0019_0020  0021_0022  0034_0027
> >       0011_0017  0016_0019  0021_0021  0032_0026
> >
> >     - With ACPI PCI slot detection driver
> >       # ls /sys/bus/pci/slots/
> >       0009_0016  0014_0018  0019_0020  0021_0022  27
> >       0011_0017  0016_0019  0021_0021  26
> >
> >     I had thought it is not a big problem before because people who
> >     don't like new names would not load the PCI slot driver. But since
> >     it is loaded automatically at boot time, I'm wondering that it
> >     would be a problem. For example, some platform, not fujitsu,
> >     depends on the old slot name to work, IIRC (Maybe Kristen knows
> >     the background about it). And I don't think the fact that slot
> >     names are changed depending on the order of driver loading is
> >     acceptable by system management people/software, though I don't
> >     have such software.
> >
> >     Though I don't have any specific idea about this, folliwings might
> >     be candidates.
> >
> >     - Override slot names with hotplug driver's slot names
>
> I think this should be done - if the pci slot driver detects that a
> hotplug driver is controlling a slot, it should allow that driver to
> set the name of the slot.

Yes, it is what I thought.
But maybe we should try unifying slots names first, I think.

> >     - Unify slot names among all hotplug drivers
>
> I'm not sure if we can do this, since slot name might depend on what
> spec people are implementing.

I'm not sure too. But I think we can unify the slot names using the
combination of chassis number and slot number among the controllers
which is based on PCI Hot-Plug spec.

> >     - Stop automatic loading of ACPI PCI slot driver
>
> I think we should definitely implement this one ^^^.

Yes. It's the simplest workaround.

BTW, I'll be out of office tomorrow. So replying to this discussion
will be delayed. I'm sorry about that.

Thanks,
Kenji Kaneshige

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