Created attachment 107192 [details]
dmesg without acpiphp.disable=1 (non-working case)

dmesg minimal boot of 3.11rc4 without acpiphp.disable=1

Created attachment 107193 [details]
dmesg with acpiphp.disable=1 (working case)

dmesg of minimal boot with acpiphp.disable=1. After booting, I inserted my ExpressCard.

Created attachment 107194 [details]
tarball of binary acpidump from X200s

acpidump -b

Created attachment 107195 [details]
plain text ascii version of acpidump (gzip'ed)

For reference: I tried an older SUSE kernel which has acpiphp and pciehp as modules.
It is 3.7.10 (actually it's the openSUSE 12.3 kernel).

Trying to load the acpiphp module there fails with ENODEV, so only pciehp can be loaded on that one.

Created attachment 107351 [details]
"lspci -vvv" of my x200s

As requested by Bjorn, "lspci -vvv", the ExpressCard is not present.

fixed in commit 3dc48af310709b85d07c8b0d3aa8f1ead02829d3

this will appear in 3.12-rc series?

It should appear in v3.12-rc1, and then be backported to the v3.10 and v3.11 stable kernels soon after that.

Ok, I'll test it early in the 3.12-rc series and report back.

Created attachment 107369 [details]
patch from Neil Horman

This is the patch referred to in comment #7.  Here's my analysis of the behavior before and after Neil's patch.

Current behavior (before Neil's patch):

  acpi_pci_root_add
    root = kzalloc                      # root->osc_control_set = 0
    acpi_pci_osc_support                # indicate OS support for segments
    root->bus = pci_acpi_scan_root
      pci_create_root_bus
        pcibios_add_bus
          acpi_pci_add_bus
            acpiphp_enumerate_slots
              init_bridge_misc
                acpi_walk_namespace(..., register_slot, ...)
                  register_slot
                    device_is_managed_by_native_pciehp
                      <test root->osc_control_set>      # root->osc_control_set == 0
                    return if OS has PCIe hotplug control
                    acpiphp_register_hotplug_slot
    acpi_pci_osc_support                # indicate OS support for MSI, ASPM, etc
    if (_osc_support() failed)
      pci_no_aspm
        aspm_disabled = 1
    acpi_pci_osc_control_set            # request OS control of hotplug, PME, AER, etc
      root->osc_control_set = XX
    if (_osc_control_set() succeeded) {
      if (FADT NO_ASPM bit)
        pcie_clear_aspm
          list_for_each_entry(..., &bus->devices, ...)
            __pci_disable_link_state
    } else {                            # _osc_control_set() failed
      pcie_no_aspm
        aspm_disabled = 1
    }


After Neil's patch:
  acpi_pci_root_add
    root = kzalloc                      # root->osc_control_set = 0
    acpi_pci_osc_support                # indicate OS support for segments
    if (_osc_support() failed)
      no_aspm = true
    acpi_pci_osc_support                # indicate OS support for MSI, ASPM, etc
    acpi_pci_osc_control_set            # request OS control of hotplug, PME, AER, etc
      root->osc_control_set = XX
    if (_osc_control_set() succeeded) {
      if (FADT NO_ASPM bit)
        clear_aspm = true
    } else {                            # _osc_control_set() failed
      no_aspm = true
    }
    root->bus = pci_acpi_scan_root
      pci_create_root_bus
        pcibios_add_bus
          acpi_pci_add_bus
            acpiphp_enumerate_slots
              acpi_walk_namespace(..., register_slot, ...)
                register_slot
                  device_is_managed_by_native_pciehp
                    <test root->osc_control_set>
                  return if OS has PCIe hotplug control
                  acpiphp_register_hotplug_slot
    if (clear_aspm)
      pcie_clear_aspm(root->bus)
        list_for_each_entry(..., &bus->devices, ...)
          __pci_disable_link_state
    if (no_aspm)
      pcie_no_aspm
        aspm_disabled = 1

Here are my notes about when this broke and what kernels need fixing.

In v3.8:
    acpi_pci_root_add
      acpi_pci_osc_control_set          # request OS control
      pci_acpi_scan_root                # scan bus
    acpi_pci_root_start
      add_bridge                        # acpi_pci_driver .add method
        ...
          device_is_managed_by_native_pciehp  # OK

In v3.9:
    acpi_pci_root_add
      pci_acpi_scan_root                # scan bus
      acpi_pci_osc_control_set          # request OS control
      add_bridge                        # acpi_pci_driver .add method
        ...
          device_is_managed_by_native_pciehp  # OK

In v3.10:
    acpi_pci_root_add
      pci_acpi_scan_root                # scan bus
        ...
          acpiphp_enumerate_slots
            ...
              device_is_managed_by_native_pciehp  # BROKEN (by 3b63aaa70e)
      acpi_pci_osc_control_set          # request OS control

In v3.12:
    acpi_pci_root_add
      acpi_pci_osc_control_set          # request OS control
      pci_acpi_scan_root                # scan bus
        ...
          acpiphp_enumerate_slots
            ...
              device_is_managed_by_native_pciehp  # FIXED

v3.12-rc1 contains Neil's patch.  Can you please retest with
v3.12-rc1 or later, attach the complete dmesg log, and note
whether this issue is resolved?

Created attachment 109271 [details]
dmesg of working minimal boot of 3.12rc1

3.12rc1 works.
I booted pretty minimal kernel config (to speed up compilation) into init=/bin/bash without acpiphp.disable=1, then inserted ExpressCard, it was detected and worked (after manually inserting xhci_hcd, no udev running in minimal boot mode).

=> seems fixed, will test more once 3.12rc lands in openSUSE Kernel repositories :-)

Thanks!

Thanks for testing this, Stefan.  I'm going to mark this as resolved, but please reopen it if further testing shows any issues.