Description of problem:

On some systems, the ACPI bus check event can reference a bridge that is
higher in the ACPI hierarchy than the bridge immediately above the
hotplug PCI slot into which an adapter was just inserted.  The current
'acpiphp' code expects the bus check event to reference the bridge
immediately above the slot that received the adapter so the hotplug
operation can fail on these systems with the message "acpiphp_glue:
cannot get bridge info".

Version-Release number of selected component (if applicable):
kernel 2.6.9-55.ELlargesmp  SMP x86_64

How reproducible:
Always

Steps to Reproduce:
1. Vacate at least one hotplug PCIe slot and boot system.
2. Load the ACPI PCI hotplug driver:
     # modprobe acpiphp
3. Attempt to hotplug a PCIe adapter.
4. Observe the "acpiphp_glue: cannot get bridge info" log
  message and lack of power to the PCIe slot (green slot
  LED is off).


Additional info:
Patch available in upstream and also backported to RHEL4 2.6.9-59.el

Upstream patch:
From 0bbd6424c55f0ab9e7fcd6a851bc49e265259ff5 Mon Sep 17 00:00:00 2001
From: Gary Hade <garyhade.com>
Date: Thu, 5 Jul 2007 11:10:48 -0700
Subject: [PATCH] PCI: hotplug: acpiphp: avoid acpiphp "cannot get bridge info"
PCI hotplug failure