linux/include
Rafael J. Wysocki 805d410fb0 ACPI: Separate adding ACPI device objects from probing ACPI drivers
Split the ACPI namespace scanning for devices into two passes, such
that struct acpi_device objects are registerd in the first pass
without probing ACPI drivers and the drivers are probed against them
directly in the second pass.

There are two main reasons for doing that.

First, the ACPI PCI root bridge driver's .add() routine,
acpi_pci_root_add(), causes struct pci_dev objects to be created for
all PCI devices under the given root bridge.  Usually, there are
corresponding ACPI device nodes in the ACPI namespace for some of
those devices and therefore there should be "companion" struct
acpi_device objects to attach those struct pci_dev objects to.  These
struct acpi_device objects should exist when the corresponding
struct pci_dev objects are created, but that is only guaranteed
during boot and not during hotplug.  This leads to a number of
functional differences between the boot and the hotplug cases which
are not strictly necessary and make the code more complicated.

For example, this forces the ACPI PCI root bridge driver to defer the
registration of the just created struct pci_dev objects and to use a
special .start() callback routine, acpi_pci_root_start(), to make
sure that all of the "companion" struct acpi_device objects will be
present at PCI devices registration time during hotplug.

If those differences can be eliminated, we will be able to
consolidate the boot and hotplug code paths for the enumeration and
registration of PCI devices and to reduce the complexity of that
code quite a bit.

The second reason is that, in general, it should be possible to
resolve conflicts of resources assigned by the BIOS to different
devices represented by ACPI namespace nodes before any drivers bind
to them and before they are attached to "companion" objects
representing physical devices (such as struct pci_dev).  However, for
this purpose we first need to enumerate all ACPI device nodes in the
given namespace scope.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>
2013-01-03 13:09:36 +01:00
..
acpi ACPI: Separate adding ACPI device objects from probing ACPI drivers 2013-01-03 13:09:36 +01:00
asm-generic These are a few cleanups for asm-generic: 2012-12-21 16:39:08 -08:00
clocksource
crypto
drm Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel into drm-next 2012-12-30 13:54:12 +10:00
keys
linux PCI updates for v3.8: 2013-01-02 17:44:29 -08:00
math-emu
media
memory
misc
net netprio_cgroup: define sk_cgrp_prioidx only if NETPRIO_CGROUP is enabled 2012-12-26 14:16:23 -08:00
pcmcia
ras
rdma UAPI: Remove empty Kbuild files 2013-01-02 17:36:10 -08:00
rxrpc
scsi SCSI misc on 20121212 2012-12-13 19:20:31 -08:00
sound UAPI: Remove empty Kbuild files 2013-01-02 17:36:10 -08:00
target target/iscsi_target: Add NodeACL tags for initiator group support 2012-12-13 14:18:09 -08:00
trace Various bug fixes for ext4. Perhaps the most serious bug fixed is one 2013-01-02 09:57:34 -08:00
uapi PCI updates for v3.8: 2013-01-02 17:44:29 -08:00
video Merge branch 'omap-for-v3.8/fixes-for-merge-window' into omap-for-v3.8/fixes-for-merge-window-v2 2012-12-16 11:28:10 -08:00
xen Bugfixes: 2012-12-18 12:26:54 -08:00
Kbuild UAPI: Remove empty Kbuild files 2013-01-02 17:36:10 -08:00