The mechanism causing devices depending on a given power resource
(that is, devices that can be in D0 only if that power resource is
on) to be resumed automatically when the power resource is turned
on (and their "inferred" power state becomes D0 as a result) is
inherently racy and in fact unnecessary.
It is racy, because if the power resource is turned on and then
immediately off, the device resume triggered by the first transition
to "on" may still happen, causing the power resource to be turned
on again. That again will trigger the "resume of dependent devices"
mechanism, but if the devices in question are not in use, they will
be suspended in the meantime causing the power resource to be turned
off. However, the "resume of dependent devices" will next resume
them again and so on. In some cases (USB port PM in particular) that
leads to an endless busy loop of flipping the resource on and off
continuously.
It is needless, because whoever turns a power resource on will most
likely turn it off at some point and the devices that go into "D0"
as a result of turning it on will then go back into D3cold
(generally, the state they were in before).
Moreover, turning on all power resources a device needs to go into
D0 is not sufficient for a full transition into D0 in general.
Namely, _PS0 may need to be executed in addition to that in some
cases. This means that the whole rationale of the "resume of
dependent devices" mechanism was incorrect to begin with and it's
best to remove it entirely.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In acpi_resume_power_resources() resource_lock should be released
when acpi_power_get_state() fails and before passing to next power
resource on the list.
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* acpi-pm:
ACPI / PM: Add state information to error message in acpi_device_set_power()
ACPI / PM: Remove redundant power manageable check from acpi_bus_set_power()
ACPI / PM: Use ACPI_STATE_D3_COLD instead of ACPI_STATE_D3 everywhere
ACPI / PM: Make messages in acpi_device_set_power() print device names
ACPI / PM: Only set power states of devices that are power manageable
There are several places in the tree where ACPI_STATE_D3 is used
instead of ACPI_STATE_D3_COLD which should be used instead for
clarity. Modify them all to use ACPI_STATE_D3_COLD as appropriate.
[The definition of ACPI_STATE_D3 itself cannot go away at this point
as it is part of ACPICA.]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Introduce helper function acpi_execute_simple_method() and use it in
a number of places to simplify code.
[rjw: Changelog]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are few places in power.c where debug messages have no newline
at the end. Reading such debug messages from dmesg is not fun, so
fix this by adding the missing newlines.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: All <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit 781d737 (ACPI: Drop power resources driver) introduced a
bug in the power resources initialization error code path causing
a NULL pointer to be referenced in acpi_release_power_resource()
if there's an error triggering a jump to the 'err' label in
acpi_add_power_resource(). This happens because the list_node
field of struct acpi_power_resource has not been initialized yet
at this point and doing a list_del() on it is a bad idea.
To prevent this problem from occuring, initialize the list_node
field of struct acpi_power_resource upfront.
Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 3.9+ <stable@vger.kernel.org>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Commit 18a3870 (ACPI / PM: Expose lists of device power resources
to user space) exposed the lists of ACPI power resources associated
with power states of ACPI devices, but it didn't expose the lists
of ACPI wakeup power resources, which also is necessary to get the
full picture of dependencies between ACPI devices and power
resources.
For this reason, for every ACPI device node having a list of ACPI
wakeup power resources associated with it, expose that list to user
space in analogy with commit 18a3870.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch introduces acpi_set_pnp_ids() and acpi_free_pnp_ids(),
which are updated from acpi_device_set_id() and acpi_free_ids(),
to setup and free acpi_device_pnp for a given acpi_handle. They
can be called without acpi_device.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit d2e5f0c (ACPI / PCI: Rework the setup and cleanup of device
wakeup) moved the initial disabling of system wakeup for PCI devices
into a place where it can actually work and that exposed a hidden old
issue with crap^Wunusual system designs where the same power
resources are used for both wakeup power and device power control at
run time.
Namely, say there is one power resource such that the ACPI power
state D0 of a PCI device depends on that power resource (i.e. the
device is in D0 when that power resource is "on") and it is used
as a wakeup power resource for the same device. Then, calling
acpi_pci_sleep_wake(pci_dev, false) for the device in question will
cause the reference counter of that power resource to drop to 0,
which in turn will cause it to be turned off. As a result, the
device will go into D3cold at that point, although it should have
stayed in D0.
As it turns out, that happens to USB controllers on some laptops
and USB becomes unusable on those machines as a result, which is
a major regression from v3.8.
To fix this problem, (1) increment the reference counters of wakup
power resources during their initialization if they are "on"
initially, (2) prevent acpi_disable_wakeup_device_power() from
decrementing the reference counters of wakeup power resources that
were not enabled for wakeup power previously, and (3) prevent
acpi_enable_wakeup_device_power() from incrementing the reference
counters of wakeup power resources that already are enabled for
wakeup power.
In addition to that, if it is impossible to determine the initial
states of wakeup power resources, avoid enabling wakeup for devices
whose wakeup power depends on those power resources.
Reported-by: Dave Jones <davej@redhat.com>
Reported-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Tested-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
During system resume we check if there are power resources that have
been turned off by the BIOS, but our reference counters for them
are nonzero (they need to be turned on then). It turns out, however,
that we also need to check the opposite, i.e. if there are power
resources that have been turned on by the BIOS, but our reference
counters for them are zero (which means that no devices are going
to need them any time soon) and we should turn them off.
Make the power resources resume code do the additional check and
turn off the unused power resources as appropriate.
This change has been tested on HP nx6325.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since ACPI power resources are going to be used more extensively on
new hardware platforms, it is necessary to allow user space (powertop
in particular) to look at the lists of power resources corresponding
to different power states of devices for diagnostics and control
purposes.
For this reason, for each power state of an ACPI device node using
power resources create a special attribute group under the device
node's directory in sysfs containing links to sysfs directories
representing the power resources in that list. The names of the
new attribute groups are "power_resources_<state>", where <state>
is the state name i.e. "D0", "D1", "D2", or "D3hot".
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since ACPI power resources are going to be used more extensively on
new hardware platforms, it becomes necessary for user space (powertop
in particular) to observe some properties of those resources for
diagnostics purposes.
For this reason, expose the current status of each ACPI power
resource to user space via sysfs by adding a new resource_in_use
attribute to the sysfs directory representing the given power
resource.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ACPI core adds sysfs device files after the given devices have been
registered with device_register(), which is not appropriate, because
it may lead to race conditions with user space tools using those
files.
Fix the problem by delaying the KOBJ_ADD uevent for ACPI devices
until after all of the devices' sysfs files have been created.
This also fixes a use-after-free in acpi_device_unregister().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After the only user of acpi_power_on_resources(),
acpi_bus_init_power(), has been changed to avoid calling it
for state equal to ACPI_STATE_D3_COLD, it doesn't have to special
case that state any more.
For this reason, modify the checks in acpi_power_on_resources()
so that it returns -EINVAL for ACPI_STATE_D3_COLD as it should.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The system level attribute of ACPI power resources is the lowest
system sleep level (S0, S2 etc.) in which the given resource can be
"on" (ACPI 5.0, Section 7.1). On the other hand, wakeup power
resources have to be "on" for devices depending on them to be able to
signal wakeup. Therefore devices cannot wake up the system from
sleep states higher than the minimum of the system level attributes
of their wakeup power resources.
Use the wakeup power resources' system level values to get the
deepest system sleep state (highest system sleep level) the given
device can wake up the system from.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Some ACPI power resource initialization errors, like memory
allocation errors, are not taken into account appropriately in some
cases, which may lead to a device having an incomplete list of power
resources that one of its power states depends on, for one example.
Rework the power resource initialization and namespace scanning code
so that power resource initialization errors are treated more
seriously.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The lists of ACPI power resources are currently extracted in two
different ways, one for wakeup power resources and one for power
resources that device power states depend on. There is no reason
why it should be done differently in those two cases, so introduce
a common routine for extracting power resources lists from data
returned by AML, acpi_extract_power_resources(), and make the
namespace scanning code use it for both wakeup and device power
states power resources.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI power resources have an order attribute that should be taken
into account when turning them on and off, but it is not used now.
Modify the power resources management code to preserve the
spec-compliant ordering of wakeup power resources.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI power resources have an order attribute that should be taken
into account when turning them on and off, but it is not used now.
Modify the power resources management code to preserve the
spec-compliant ordering of power resources that power states of
devices depend on (analogous changes will be done separately for
power resources used for wakeup).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI power resource objects have struct acpi_device components, but
they are only used for registering those resources in the device
hierarchy. In particular, power state information stored in them is
completely useless (amnong other things, because the power resources
"devices" are not power manageable), so there is no reason for the
power resources management code to keep it up to date.
Remove the code updating device power states of power resources from
drivers/acpi/power.c.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The ACPI power resources driver is not very useful, because the only
thing it really does is to restore the state of the power resources
that were "on" before system suspend or hibernation, but that may be
achieved in a different way.
Drop the ACPI power resources driver entirely and add
acpi_resume_power_resources() that will walk the list of all
registered power resources during system resume and turn on the ones
that were "on" before the preceding system suspend or hibernation.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI power resources need to be treated in a special way by the
namespace scanning code, because they need to be ready to use as
soon as they have been discovered (even before registering ACPI
device nodes using them for power management).
For this reason, it doesn't make sense to separate the preparation
of struct acpi_device objects representing them in the device
hierarchy from the creation of struct acpi_power_resource objects
actually used for power resource manipulation. Accordingly, it
doesn't make sense to define non-empty .add() and .remove() callbacks
in the power resources "driver" (in fact, it is questionable whether
or not it is useful to register such a "driver" at all).
Rearrange the code in scan.c and power.c so that power resources are
initialized entirely by one routine, acpi_add_power_resource(), that
also prepares their struct acpi_device objects and registers them
with the driver core, telling it to use a special release routine,
acpi_release_power_resource(), for removing objects that represent
power resources from memory. Make the ACPI namespace scanning code
in scan.c always use acpi_add_power_resource() for preparing and
registering objects that represent power resources.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit 0090def6 (ACPI: Add interface to register/unregister device
to/from power resources) made it possible to indicate to the ACPI
core that if the given device depends on any power resources, then
it should be resumed as soon as all of the power resources required
by it to transition to the D0 power state have been turned on.
Unfortunately, however, this was a mistake, because all devices
depending on power resources should be treated this way (i.e. they
should be resumed when all power resources required by their D0
state have been turned on) and for the majority of those devices
the ACPI core can figure out by itself which (physical) devices
depend on what power resources.
For this reason, replace the code added by commit 0090def6 with a
new, much more straightforward, mechanism that will be used
internally by the ACPI core and remove all references to that code
from kernel subsystems using ACPI.
For the cases when there are (physical) devices that should be
resumed whenever a not directly related ACPI device node goes into
D0 as a result of power resources configuration changes, like in
the SATA case, add two new routines, acpi_dev_pm_add_dependent()
and acpi_dev_pm_remove_dependent(), allowing subsystems to manage
such dependencies. Convert the SATA subsystem to use the new
functions accordingly.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
After commit 71fbad6 (PCI/ACPI: Notify PCI devices when their power
resource is turned on) made acpi_pci_bind() call
acpi_power_resource_register_device(), the debug message at the end
of the latter appears in the kernel log for every PCI device that
doesn't happen to have power resources assigned (which is the vast
majority of them). However, this message is totally useless, because
it doesn't even say which device it is about. Moreover, it is
misleading, because it only means that the given device has no power
resources, which isn't exceptional at all.
Remove that useless message altogether and simplify
acpi_power_resource_register_device() slightly.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add newline to printk so that the message is on a line
by itself and not merged with something unrelated to it.
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
commit a606dac368 adds support to link
devices which have _PRx, if a device does not have _PRx, a warning
message will be printed.
This commit is for ZPODD on Intel ZPODD capable platforms, on other
platforms, it has no problem if there is no power resource for this
device, so a warning here is not appropriate, change it to debug.
Reported-by: Borislav Petkov <bp@amd64.org>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Commit 0090def("ACPI: Add interface to register/unregister device
to/from power resources") used resource_lock to protect the devices list
that relies on power resource. It caused a mutex dead lock, as below
acpi_power_on ---> lock resource_lock
__acpi_power_on
acpi_power_on_device
acpi_power_get_inferred_state
acpi_power_get_list_state ---> lock resource_lock
This patch adds a new mutex "devices_lock" to protect the devices list
and calls acpi_power_on_device in acpi_power_on, instead of
__acpi_power_on, after the resource_lock is released.
[rjw: Changed data type of a boolean variable to bool.]
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
According to compiler warnings, several suspend/resume functions
in ACPI drivers are not used for CONFIG_PM_SLEEP unset, so add
#ifdefs to prevent them from being built in that case.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Two bits were appended to the end of the bitfield
list in struct scsi_device. Resolve that conflict
by including both bits.
Conflicts:
include/scsi/scsi_device.h
Make the ACPI power resource driver define its PM callbacks through
a struct dev_pm_ops object rather than by using legacy PM hooks
in struct acpi_device_ops.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
After recent changes of the ACPI device power states definitions, if
power resources are not used for the device's power management, the
state returned by __acpi_bus_get_power() cannot exceed D3hot, because
the return values of _PSC are 0 through 3. However, if the _PR3
method is not present for the device and _PS3 returns 3, we have to
assume that the device is in D3cold, so the value returned by
__acpi_bus_get_power() in that case should be 4.
Similarly, acpi_power_get_inferred_state() should take the power
resources for the D3hot state into account in general, so that it
can return 3 if those resources are "on" or 4 (D3cold) otherwise.
Fix the the above two issues and make sure that if both _PSC and
_PR3 are present for the device, the power resources listed by _PR3
will be used to determine if the number 3 returned by _PSC is meant
to represent D3cold or D3hot.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Commit 1cc0c998fd ("ACPI: Fix D3hot v D3cold confusion") introduced a
bug in __acpi_bus_set_power() and changed the behavior of
acpi_pci_set_power_state() in such a way that it generally doesn't work
as expected if PCI_D3hot is passed to it as the second argument.
First off, if ACPI_STATE_D3 (equal to ACPI_STATE_D3_COLD) is passed to
__acpi_bus_set_power() and the explicit_set flag is set for the D3cold
state, the function will try to execute AML method called "_PS4", which
doesn't exist.
Fix this by adding a check to ensure that the name of the AML method
to execute for transitions to ACPI_STATE_D3_COLD is correct in
__acpi_bus_set_power(). Also make sure that the explicit_set flag
for ACPI_STATE_D3_COLD will be set if _PS3 is present and modify
acpi_power_transition() to avoid accessing power resources for
ACPI_STATE_D3_COLD, because they don't exist.
Second, if PCI_D3hot is passed to acpi_pci_set_power_state() as the
target state, the function will request a transition to
ACPI_STATE_D3_HOT instead of ACPI_STATE_D3. However,
ACPI_STATE_D3_HOT is now only marked as supported if the _PR3 AML
method is defined for the given device, which is rare. This causes
problems to happen on systems where devices were successfully put
into ACPI D3 by pci_set_power_state(PCI_D3hot) which doesn't work
now. In particular, some unused graphics adapters are not turned
off as a result.
To fix this issue restore the old behavior of
acpi_pci_set_power_state(), which is to request a transition to
ACPI_STATE_D3 (equal to ACPI_STATE_D3_COLD) if either PCI_D3hot or
PCI_D3cold is passed to it as the argument.
This approach is not ideal, because generally power should not
be removed from devices if PCI_D3hot is the target power state,
but since this behavior is relied on, we have no choice but to
restore it at the moment and spend more time on designing a
better solution in the future.
References: https://bugzilla.kernel.org/show_bug.cgi?id=43228
Reported-by: rocko <rockorequin@hotmail.com>
Reported-by: Cristian RodrÃguez <crrodriguez@opensuse.org>
Reported-and-tested-by: Peter <lekensteyn@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Before this patch, ACPI_STATE_D3 incorrectly referenced D3hot
in some places, but D3cold in other places.
After this patch, ACPI_STATE_D3 always means ACPI_STATE_D3_COLD;
and all references to D3hot use ACPI_STATE_D3_HOT.
ACPI's _PR3 method is used to enter both D3hot and D3cold states.
What distinguishes D3hot from D3cold is the presence _PR3
(Power Resources for D3hot) If these resources are all ON,
then the state is D3hot. If _PR3 is not present,
or all _PR0 resources for the devices are OFF,
then the state is D3cold.
This patch applies after Linux-3.4-rc1.
A future syntax cleanup may remove ACPI_STATE_D3
to emphasize that it always means ACPI_STATE_D3_COLD.
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Aaron Lu <aaron.lu@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Devices may share same list of power resources in _PR0, for example
Device(Dev0)
{
Name (_PR0, Package (0x01)
{
P0PR,
P1PR
})
}
Device(Dev1)
{
Name (_PR0, Package (0x01)
{
P0PR,
P1PR
}
}
Assume Dev0 and Dev1 were runtime suspended.
Then Dev0 is resumed first and it goes into D0 state.
But Dev1 is left in D0_Uninitialised state.
This is wrong. In this case, Dev1 must be resumed too.
In order to hand this case, each power resource maintains a list of
devices which relies on it.
When power resource is ON, it will check if the devices on its list
can be resumed. The device can only be resumed when all the power
resouces of its _PR0 are ON.
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
If a device has _PR3, it means the device supports D3_COLD.
Add the ability to validate and enter D3_COLD state in ACPI.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
It certainly is not a good idea to execute _ON or _OFF and _STA
for the same power resource at the same time which may happen in
some circumstances in theory. To prevent that from happening,
read the power state of each power resource under its mutex, as
that will prevent the state from being changed at the same time.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Rename acpi_power_off_device() to acpi_power_off() in analogy with
acpi_power_on().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Since acpi_bus_set_power() should not use __acpi_bus_get_power() to
update the device's device->power.state field before changing its
power state (this may cause device->power.state to be inconsistent
with the device power resources' reference counters), remove this
call from it. In consequence, the acpi_power_nocheck variable is not
necessary any more, so it can be dropped along with the DMI table
used for setting that variable for HP Pavilion 05.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Introduce function acpi_power_on_resources() that reference counts
and possibly turns on ACPI power resources for a given device and
a given power state of it.
This function will be used for reference counting device power
resources during initialization.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
ACPI device power resources should be reference counted during
device initialization, so that their reference counters are always
up to date. It is convenient to do that with the help of a function
that will reference count and possibly turn on power resources in
a given list, so introduce that function, acpi_power_on_list().
For symmetry, introduce acpi_power_off_list() for performing the
reverse operation and use the both of them to simplify
acpi_power_transition().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
acpi_power_get_inferred_state() should not update
device->power.state behind the back of its caller, so make it return
the state via a pointer instead.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
If turning on a power resource fails, do not reference count it,
since it cannot be in use in that case.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Commit 3e384ee6c6 (ACPI / PM: Fix
reference counting of power resources) introduced a regression by
causing fan power resources to be turned on and reference counted
unnecessarily during resume, so on some boxes fans are always on
after resume.
Fix the problem by checking if the current device state is different
from the new state before reference counting and turning on power
resources in acpi_power_transition().
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=22932 .
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-and-tested-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The reference counting of ACPI power resources is currently broken
for a few reasons. First, instead of using a simple reference
counter per power resource it uses a list of objects representing
refereces to the given power resource from devices. This leads to
the second breakage, because it prevents power resources from
being referenced more than once by one device, which is necessary
if the device is configured to signal wakeup. Namely, when putting
the device into a low power state we first call
acpi_enable_wakeup_device_power() that should reference count power
resources needed for signaling wakeup and then we call
acpi_power_transition() to power off the device. The latter call
drops references to the device's power resources, possibly including
the ones added by acpi_enable_wakeup_device_power(), so the device
can't signal wakeup as a result. Apart from this, the locking
in acpi_power_on() and acpi_power_off_device() doesn't prevent
all possible races from happening, which may be problematic for
runtime PM and asynchronous suspend and resume.
Fix the problem by using a counter for power resources reference
counting and putting the evaluation of ACPI _ON and _OFF methods
under the power resource mutex.
Reported-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
gcc-4.6: ACPI: fix unused but set variables in ACPI
ACPI thermal: make procfs I/F depend on CONFIG_ACPI_PROCFS
ACPI video: make procfs I/F depend on CONFIG_ACPI_PROCFS
ACPI processor: remove deprecated ACPI procfs I/F
ACPI power_resource: remove unused procfs I/F
ACPI: remove deprecated ACPI procfs I/F
ACPI: introduce drivers/acpi/sysfs.c
ACPI: introduce module parameter acpi.aml_debug_output
ACPI: introduce drivers/acpi/debugfs.c
ACPI, APEI, ERST debug support
ACPI, APEI, Manage GHES as platform devices
ACPI, APEI, Rename CPER and GHES severity constants
ACPI, APEI, Fix a typo of error path of apei_resources_request
ACPI / ACPICA: Fix reference counting problems with GPE handlers
ACPI: Add the check of ADR flag in course of finding ACPI handle for PCI device
ACPI / Sleep: Drop acpi_suspend_finish()
ACPI / Sleep: Consolidate suspend and hibernation routines
ACPI / Wakeup: Simplify enabling of wakeup devices
ACPI / Sleep: Rework enabling wakeup devices
ACPI / Sleep: Free NVS copy if suspending of devices fails
Fixed up totally buggered "ACPI: fix unused but set variables in ACPI"
patch that doesn't even compile in the merge.
Thanks to Sedat Dilek <sedat.dilek@googlemail.com> for noticing the
breakage before I even pulled. And a big "Grrr.." at Len for not even
bothering to compile the tree before asking me to pull.
Some minor improvements in error handling, but overall it was mostly dead
code.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Rafael J. Wysocki