ACPI / notify: Clean up handling of hotplug events

Make the handling of hotplug events in acpi_bus_notify() slightly
cleaner by using an extra local variable to indicate when
acpi_hotplug_schedule() should be called.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge branch 'acpi-hotplug' into bleeding-edge

* acpi-hotplug:
  ACPI / notify: Clean up handling of hotplug events
ACPI / video: change acpi-video brightness_switch_enabled default to 0

acpi-video is unique in that it not only generates brightness up/down
keypresses, but also (sometimes) actively changes the brightness itself.

This presents an inconsistent kernel interface to userspace, basically there
are 2 different scenarios, depending on the laptop model:

 1) On some laptops a brightness up/down keypress means: show a brightness osd
 with the current brightness, iow it is a brightness has changed notification.

 2) Where as on (a lot of) other laptops it means a brightness up/down key was
 pressed, deal with it.

Most of the desktop environments interpret any press as in scenario 2, and
change the brightness up / down as a response to the key events, causing it
to be changed twice, once by acpi-video and once by the DE.

With the new default for video.use_native_backlight we will be moving even
more laptops over to behaving as in scenario 2. Making the remaining laptops
even more of a weird exception. Also note that it is hard to detect scenario
1 properly in userspace, and AFAIK none of the DE-s deals with it.

Therefor this commit changes the default of brightness_switch_enabled to 0
making its behavior consistent with all the other backlight drivers.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge branch 'acpi-video-next' into bleeding-edge

* acpi-video-next:
  ACPI / video: change acpi-video brightness_switch_enabled default to 0
ACPI / PCI: Stub out pci_acpi_crs_quirks() and make it x86 specific

For pci_acpi_crs_quirks(), ia64 already doesn't use it, and we can
not foresee it should be used in ARM64, so stub out pci_acpi_crs_quirks()
to avoid introducing platform specific dummy stub function.

Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge branch 'acpi-pci' into bleeding-edge

* acpi-pci:
  ACPI / PCI: Stub out pci_acpi_crs_quirks() and make it x86 specific