linux-stable.git/drivers/acpi/container.c, branch linux-3.14.y

ACPI / hotplug: Generate online uevents for ACPI containers

2014-10-05T21:52:16+00:00

commit 8ab17fc92e49bc2b8fff9d220c19bf50ec9c1158 upstream.

Commit 46394fd01 (ACPI / hotplug: Move container-specific code out of
the core) removed the generation of "online" uevents for containers,
because "add" uevents are now generated for them automatically when
container system devices are registered.  However, there are user
space tools that need to be notified when the container and all of
its children have been enumerated, which doesn't happen any more.

For this reason, add a mechanism allowing "online" uevents to be
generated for ACPI containers after enumerating the container along
with all of its children.

Fixes: 46394fd01 (ACPI / hotplug: Move container-specific code out of the core)
Reported-and-tested-by: Yasuaki Ishimatsu 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

ACPI / container: Fix error code path in container_device_attach()

2014-02-12T13:55:16+00:00

To avoid leaking memory on errors from device_register(), do a
put_device() on the device object in question in the error code
path of container_device_attach().

Fixes: caa73ea158de (ACPI / hotplug / driver core: Handle containers in a special way)
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Yasuaki Ishimatsu

ACPI / hotplug / driver core: Handle containers in a special way

2013-12-29T14:25:48+00:00

ACPI container devices require special hotplug handling, at least
on some systems, since generally user space needs to carry out
system-specific cleanup before it makes sense to offline devices in
the container.  However, the current ACPI hotplug code for containers
first attempts to offline devices in the container and only then it
notifies user space of the container offline.

Moreover, after commit 202317a573b2 (ACPI / scan: Add acpi_device
objects for all device nodes in the namespace), ACPI device objects
representing containers are present as long as the ACPI namespace
nodes corresponding to them are present, which may be forever, even
if the container devices are physically detached from the system (the
return values of the corresponding _STA methods change in those
cases, but generally the namespace nodes themselves are still there).
Thus it is useful to introduce entities representing containers that
will go away during container hot-unplug.

The goal of this change is to address both the above issues.

The idea is to create a "companion" container system device for each
of the ACPI container device objects during the initial namespace
scan or on a hotplug event making the container present.  That system
device will be unregistered on container removal.  A new bus type
for container devices is added for this purpose, because device
offline and online operations need to be defined for them.  The
online operation is a trivial function that is always successful
and the offline uses a callback pointed to by the container device's
offline member.

For ACPI containers that callback simply walks the list of ACPI
device objects right below the container object (its children) and
checks if all of their physical companion devices are offline.  If
that's not the case, it returns -EBUSY and the container system
devivce cannot be put offline.  Consequently, to put the container
system device offline, it is necessary to put all of the physical
devices depending on its ACPI companion object offline beforehand.

Container system devices created for ACPI container objects are
initially online.  They are created by the container ACPI scan
handler whose hotplug.demand_offline flag is set.  That causes
acpi_scan_hot_remove() to check if the companion container system
device is offline before attempting to remove an ACPI container or
any devices below it.  If the check fails, a KOBJ_CHANGE uevent is
emitted for the container system device in question and user space
is expected to offline all devices below the container and the
container itself in response to it.  Then, user space can finalize
the removal of the container with the help of its ACPI device
object's eject attribute in sysfs.

Tested-by: Yasuaki Ishimatsu 
Signed-off-by: Rafael J. Wysocki 
Acked-by: Greg Kroah-Hartman

ACPI / hotplug: Move container-specific code out of the core

2013-11-22T20:55:32+00:00

Move container-specific uevents from the core hotplug code to the
container scan handler's .attach() and .detach() callbacks.

This way the core will not have to special-case containers and
the uevents will be guaranteed to happen every time a container
is either scanned or trimmed as appropriate.

Signed-off-by: Rafael J. Wysocki 
Tested-by: Mika Westerberg

Merge branch 'acpi-assorted'

2013-04-27T23:54:08+00:00

* acpi-assorted: (21 commits)
  ACPI / thermal: do not always return THERMAL_TREND_RAISING for active trip points
  ACPI: video: correct acpi_video_bus_add error processing
  ACPI: Fix wrong parameter passed to memblock_reserve
  acpi: video: enhance the quirk detect logic of _BQC
  ACPI: update comments for acpi_event_status
  ACPI: remove "config ACPI_DEBUG_FUNC_TRACE"
  PCI / ACPI: Don't query OSC support with all possible controls
  ACPI / processor_thermal: avoid null pointer deference error
  ACPI / fan: avoid null pointer deference error
  ACPI / video: Fix applying indexed initial brightness value.
  ACPI / video: Make logic a little easier to understand.
  ACPI / video: Fix brightness control initialization for some laptops.
  ACPI: Use resource_size() in osl.c
  ACPI / acpi_pad: Used PTR_RET
  ACPI: suppress compiler warning in container.c
  ACPI: suppress compiler warning in battery.c
  ACPI: suppress compiler warnings in processor_throttling.c
  ACPI: suppress compiler warnings in button.c
  ACPI: replace kmalloc+memcpy with kmemdup
  ACPI: Remove acpi_pci_bind_root() definition
  ...

ACPI: suppress compiler warning in container.c

2013-03-24T23:05:48+00:00

This patch fixes following compiler warning when build via make W=1:

drivers/acpi/container.c:183:116: warning: no previous prototype for ‘acpi_container_init’ [-Wmissing-prototypes]

Signed-off-by: Andy Shevchenko 
Signed-off-by: Rafael J. Wysocki

ACPI / container: Use hotplug profile user space interface

2013-03-04T13:25:32+00:00

Make the ACPI container driver register its ACPI scan handler object
using acpi_scan_add_handler_with_hotplug() to allow user space to
manipulate its hotplug profile attributes.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Toshi Kani 
Tested-by: Toshi Kani

ACPI / container: Use common hotplug code

2013-03-04T13:25:32+00:00

Switch the ACPI container driver to using common device hotplug code
introduced previously.  This reduces the driver down to a trivial
definition and registration of a struct acpi_scan_handler object.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Toshi Kani 
Tested-by: Toshi Kani

ACPI / hotplug: Fix concurrency issues and memory leaks

2013-02-13T13:36:47+00:00

This changeset is aimed at fixing a few different but related
problems in the ACPI hotplug infrastructure.

First of all, since notify handlers may be run in parallel with
acpi_bus_scan(), acpi_bus_trim() and acpi_bus_hot_remove_device()
and some of them are installed for ACPI handles that have no struct
acpi_device objects attached (i.e. before those objects are created),
those notify handlers have to take acpi_scan_lock to prevent races
from taking place (e.g. a struct acpi_device is found to be present
for the given ACPI handle, but right after that it is removed by
acpi_bus_trim() running in parallel to the given notify handler).
Moreover, since some of them call acpi_bus_scan() and
acpi_bus_trim(), this leads to the conclusion that acpi_scan_lock
should be acquired by the callers of these two funtions rather by
these functions themselves.

For these reasons, make all notify handlers that can handle device
addition and eject events take acpi_scan_lock and remove the
acpi_scan_lock locking from acpi_bus_scan() and acpi_bus_trim().
Accordingly, update all of their users to make sure that they
are always called under acpi_scan_lock.

Furthermore, since eject operations are carried out asynchronously
with respect to the notify events that trigger them, with the help
of acpi_bus_hot_remove_device(), even if notify handlers take the
ACPI scan lock, it still is possible that, for example,
acpi_bus_trim() will run between acpi_bus_hot_remove_device() and
the notify handler that scheduled its execution and that
acpi_bus_trim() will remove the device node passed to
acpi_bus_hot_remove_device() for ejection.  In that case, the struct
acpi_device object obtained by acpi_bus_hot_remove_device() will be
invalid and not-so-funny things will ensue.  To protect agaist that,
make the users of acpi_bus_hot_remove_device() run get_device() on
ACPI device node objects that are about to be passed to it and make
acpi_bus_hot_remove_device() run put_device() on them and check if
their ACPI handles are not NULL (make acpi_device_unregister() clear
the device nodes' ACPI handles for that check to work).

Finally, observe that acpi_os_hotplug_execute() actually can fail,
in which case its caller ought to free memory allocated for the
context object to prevent leaks from happening.  It also needs to
run put_device() on the device node that it ran get_device() on
previously in that case.  Modify the code accordingly.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Yinghai Lu

ACPI: Drop the container.h header file

2013-02-13T12:43:02+00:00

The include/acpi/container.h only contains a definition of a
structure that is not used any more, so drop it entirely.

Similar change was proposed earlier by Toshi Kani.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Toshi Kani