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

[Kristen Carlson Accardi <kristen.c.accardi@intel.com>]

On Tue, 11 Mar 2008 22:10:40 +0900
Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> 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.

>     - 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.

>     - Stop automatic loading of ACPI PCI slot driver

I think we should definitely implement this one ^^^.