According to Matthew Garrett, "Windows 8 leaves backlight control up
to individual graphics drivers rather than making ACPI calls itself.
There's plenty of evidence to suggest that the Intel driver for
Windows [8] doesn't use the ACPI interface, including the fact that
it's broken on a bunch of machines when the OS claims to support
Windows 8.  The simplest thing to do appears to be to disable the
ACPI backlight interface on these systems".

There's a problem with that approach, however, because simply
avoiding to register the ACPI backlight interface if the firmware
calls _OSI for Windows 8 may not work in the following situations:
 (1) The ACPI backlight interface actually works on the given system
     and the i915 driver is not loaded (e.g. another graphics driver
     is used).
 (2) The ACPI backlight interface doesn't work on the given system,
     but there is a vendor platform driver that will register its
     own, equally broken, backlight interface if not prevented from
     doing so by the ACPI subsystem.
Therefore we need to allow the ACPI backlight interface to be
registered until the i915 driver is loaded which then will unregister
it if the firmware has called _OSI for Windows 8 (or will register
the ACPI video driver without backlight support if not already
present).

For this reason, introduce an alternative function for registering
ACPI video, acpi_video_register_with_quirks(), that will check
whether or not the ACPI video driver has already been registered
and whether or not the backlight Windows 8 quirk has to be applied.
If the quirk has to be applied, it will block the ACPI backlight
support and either unregister the backlight interface if the ACPI
video driver has already been registered, or register the ACPI
video driver without the backlight interface otherwise.  Make
the i915 driver use acpi_video_register_with_quirks() instead of
acpi_video_register() in i915_driver_load().

This change is based on earlier patches from Matthew Garrett,
Chun-Yi Lee and Seth Forshee and includes a fix from Aaron Lu's.

References: https://bugzilla.kernel.org/show_bug.cgi?id=51231
Tested-by: Aaron Lu <aaron.lu@intel.com>
Tested-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
Tested-by: Yves-Alexis Perez <corsac@debian.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Matthew Garrett <matthew.garrett@nebula.com>

Expose acpi_gbl_osi_data so that code outside of ACPICA can check
the value of the last successfull _OSI call.  The definitions for
OSI versions are moved to actypes.h so that other components can
access them too.

Based on a patch from Matthew Garrett which in turn was based on
an earlier patch from Seth Forshee.

[rjw: Changelog]
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull PCI changes from Bjorn Helgaas:
 "PCI device hotplug
    - Add pci_alloc_dev() interface (Gu Zheng)
    - Add pci_bus_get()/put() for reference counting (Jiang Liu)
    - Fix SR-IOV reference count issues (Jiang Liu)
    - Remove unused acpi_pci_roots list (Jiang Liu)

  MSI
    - Conserve interrupt resources on x86 (Alexander Gordeev)

  AER
    - Force fatal severity when component has been reset (Betty Dall)
    - Reset link below Root Port as well as Downstream Port (Betty Dall)
    - Fix "Firmware first" flag setting (Bjorn Helgaas)
    - Don't parse HEST for non-PCIe devices (Bjorn Helgaas)

  ASPM
    - Warn when we can't disable ASPM as driver requests (Bjorn Helgaas)

  Miscellaneous
    - Add CircuitCo PCI IDs (Darren Hart)
    - Add AMD CZ SATA and SMBus PCI IDs (Shane Huang)
    - Work around Ivytown NTB BAR size issue (Jon Mason)
    - Detect invalid initial BAR values (Kevin Hao)
    - Add pcibios_release_device() (Sebastian Ott)
    - Fix powerpc & sparc PCI_UNKNOWN power state usage (Bjorn Helgaas)"

* tag 'pci-v3.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (51 commits)
  MAINTAINERS: Add ACPI folks for ACPI-related things under drivers/pci
  PCI: Add CircuitCo vendor ID and subsystem ID
  PCI: Use pdev->pm_cap instead of pci_find_capability(..,PCI_CAP_ID_PM)
  PCI: Return early on allocation failures to unindent mainline code
  PCI: Simplify IOV implementation and fix reference count races
  PCI: Drop redundant setting of bus->is_added in virtfn_add_bus()
  unicore32/PCI: Remove redundant call of pci_bus_add_devices()
  m68k/PCI: Remove redundant call of pci_bus_add_devices()
  PCI / ACPI / PM: Use correct power state strings in messages
  PCI: Fix comment typo for pcie_pme_remove()
  PCI: Rename pci_release_bus_bridge_dev() to pci_release_host_bridge_dev()
  PCI: Fix refcount issue in pci_create_root_bus() error recovery path
  ia64/PCI: Clean up pci_scan_root_bus() usage
  PCI/AER: Reset link for devices below Root Port or Downstream Port
  ACPI / APEI: Force fatal AER severity when component has been reset
  PCI/AER: Remove "extern" from function declarations
  PCI/AER: Move AER severity defines to aer.h
  PCI/AER: Set dev->__aer_firmware_first only for matching devices
  PCI/AER: Factor out HEST device type matching
  PCI/AER: Don't parse HEST table for non-PCIe devices
  ...

* acpi-assorted:
  ACPI / EC: Add HP Folio 13 to ec_dmi_table in order to skip DSDT scan
  ACPI: Add CMOS RTC Operation Region handler support
  ACPI: Remove unused flags in acpi_device_flags
  ACPI: Remove useless initializers
  ACPI / battery: Make sure all spaces are in correct places
  ACPI: add _STA evaluation at do_acpi_find_child()
  ACPI / EC: access user space with get_user()/put_user()

* acpi-pm:
  ACPI / PM: Rework and clean up acpi_dev_pm_get_state()
  ACPI / PM: Replace ACPI_STATE_D3 with ACPI_STATE_D3_COLD in device_pm.c
  ACPI / PM: Rename function acpi_device_power_state() and make it static
  ACPI / PM: acpi_processor_suspend() can be static
  xen / ACPI / sleep: Register an acpi_suspend_lowlevel callback.
  x86 / ACPI / sleep: Provide registration for acpi_suspend_lowlevel.

* acpica: (21 commits)
  ACPICA: Update version to 20130517
  ACPICA: _CST repair: Handle null package entries
  ACPICA: Add several repairs for _CST predefined name
  ACPICA: Move _PRT repair into the standard complex repair module
  ACPICA: Clear events initialized flag upon event component termination
  ACPICA: Fix possible memory leak in GPE init error path
  ACPICA: ACPICA Termination: Delete global lock pending lock
  ACPICA: Update interface to acpi_ut_valid_acpi_name()
  ACPICA: Do not use extended sleep registers unless HW-reduced bit is set
  ACPICA: Split table print utilities to a new a separate file
  ACPICA: Add option to disable loading of SSDTs from the RSDT/XSDT
  ACPICA: Standardize all switch() blocks
  ACPICA: Split internal error msg routines to a separate file
  ACPICA: Split buffer dump routines into separate file
  ACPICA: Update version to 20130418
  ACPICA: Update for "orphan" embedded controller _REG method support
  ACPICA: Remove unused macros, no functional change
  ACPICA: Predefined name support: Remove unused local variable
  ACPICA: Add argument typechecking for all predefined ACPI names
  ACPICA: Add BIOS error interface for predefined name validation support
  ...

* acpi-hotplug:
  ACPI: Do not use CONFIG_ACPI_HOTPLUG_MEMORY_MODULE
  ACPI / cpufreq: Add ACPI processor device IDs to acpi-cpufreq
  Memory hotplug: Move alternative function definitions to header
  ACPI / processor: Fix potential NULL pointer dereference in acpi_processor_add()
  Memory hotplug / ACPI: Simplify memory removal
  ACPI / scan: Add second pass of companion offlining to hot-remove code
  Driver core / MM: Drop offline_memory_block()
  ACPI / processor: Pass processor object handle to acpi_bind_one()
  ACPI: Drop removal_type field from struct acpi_device
  Driver core / memory: Simplify __memory_block_change_state()
  ACPI / processor: Initialize per_cpu(processors, pr->id) properly
  CPU: Fix sysfs cpu/online of offlined CPUs
  Driver core: Introduce offline/online callbacks for memory blocks
  ACPI / memhotplug: Bind removable memory blocks to ACPI device nodes
  ACPI / processor: Use common hotplug infrastructure
  ACPI / hotplug: Use device offline/online for graceful hot-removal
  Driver core: Use generic offline/online for CPU offline/online
  Driver core: Add offline/online device operations

The interactions between the ACPI dock driver and the ACPI-based PCI
hotplug (acpiphp) are currently problematic because of ordering
issues during hot-remove operations.

First of all, the current ACPI glue code expects that physical
devices will always be deleted before deleting the companion ACPI
device objects.  Otherwise, acpi_unbind_one() will fail with a
warning message printed to the kernel log, for example:

[  185.026073] usb usb5: Oops, 'acpi_handle' corrupt
[  185.035150] pci 0000:1b:00.0: Oops, 'acpi_handle' corrupt
[  185.035515] pci 0000:18:02.0: Oops, 'acpi_handle' corrupt
[  180.013656]  port1: Oops, 'acpi_handle' corrupt

This means, in particular, that struct pci_dev objects have to
be deleted before the struct acpi_device objects they are "glued"
with.

Now, the following happens the during the undocking of an ACPI-based
dock station:
 1) hotplug_dock_devices() invokes registered hotplug callbacks to
    destroy physical devices associated with the ACPI device objects
    depending on the dock station.  It calls dd->ops->handler() for
    each of those device objects.
 2) For PCI devices dd->ops->handler() points to
    handle_hotplug_event_func() that queues up a separate work item
    to execute _handle_hotplug_event_func() for the given device and
    returns immediately.  That work item will be executed later.
 3) hotplug_dock_devices() calls dock_remove_acpi_device() for each
    device depending on the dock station.  This runs acpi_bus_trim()
    for each of them, which causes the underlying ACPI device object
    to be destroyed, but the work items queued up by
    handle_hotplug_event_func() haven't been started yet.
 4) _handle_hotplug_event_func() queued up in step 2) are executed
    and cause the above failure to happen, because the PCI devices
    they handle do not have the companion ACPI device objects any
    more (those objects have been deleted in step 3).

The possible breakage doesn't end here, though, because
hotplug_dock_devices() may return before at least some of the
_handle_hotplug_event_func() work items spawned by it have a
chance to complete and then undock() will cause _DCK to be
evaluated and that will cause the devices handled by the
_handle_hotplug_event_func() to go away possibly while they are
being accessed.

This means that dd->ops->handler() for PCI devices should not point
to handle_hotplug_event_func().  Instead, it should point to a
function that will do the work of _handle_hotplug_event_func()
synchronously.  For this reason, introduce such a function,
hotplug_event_func(), and modity acpiphp_dock_ops to point to
it as the handler.

Unfortunately, however, this is not sufficient, because if the dock
code were not changed further, hotplug_event_func() would now
deadlock with hotplug_dock_devices() that called it, since it would
run unregister_hotplug_dock_device() which in turn would attempt to
acquire the dock station's hp_lock mutex already acquired by
hotplug_dock_devices().

To resolve that deadlock use the observation that
unregister_hotplug_dock_device() won't need to acquire hp_lock
if PCI bridges the devices on the dock station depend on are
prevented from being removed prematurely while the first loop in
hotplug_dock_devices() is in progress.

To make that possible, introduce a mechanism by which the callers of
register_hotplug_dock_device() can provide "init" and "release"
routines that will be executed, respectively, during the addition
and removal of the physical device object associated with the
given ACPI device handle.  Make acpiphp use two new functions,
acpiphp_dock_init() and acpiphp_dock_release(), that call
get_bridge() and put_bridge(), respectively, on the acpiphp bridge
holding the given device, for this purpose.

In addition to that, remove the dock station's list of
"hotplug devices" and make the dock code always walk the whole list
of "dependent devices" instead in such a way that the loops in
hotplug_dock_devices() and dock_event() (replacing the loops over
"hotplug devices") will take references to the list entries that
register_hotplug_dock_device() has been called for.  That prevents
the "release" routines associated with those entries from being
called while the given entry is being processed and for PCI
devices this means that their bridges won't be removed (by a
concurrent thread) while hotplug_event_func() handling them is
being executed.

This change is based on two earlier patches from Jiang Liu.

References: https://bugzilla.kernel.org/show_bug.cgi?id=59501
Reported-and-tested-by: Alexander E. Patrakov <patrakov@gmail.com>
Tracked-down-by: Jiang Liu <jiang.liu@huawei.com>
Tested-by: Illya Klymov <xanf@xanf.me>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Cc: 3.9+ <stable@vger.kernel.org>

Version 20130517.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 7cd8407 (ACPI / PM: Do not execute _PS0 for devices without
_PSC during initialization) introduced a regression on some systems
with Intel Lynxpoint Low-Power Subsystem (LPSS) where some devices
need to be powered up during initialization, but their device objects
in the ACPI namespace have _PS0 and _PS3 only (without _PSC or power
resources).

To work around this problem, make the ACPI LPSS driver power up
devices it knows about by using a new helper function
acpi_device_fix_up_power() that does all of the necessary
sanity checks and calls acpi_dev_pm_explicit_set() to put the
device into D0.

Reported-and-tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>