Some devices, like the I2C controller on SH7372, are not
necessary for providing power to their children or forwarding
wakeup signals (and generally interrupts) from them. They are
only needed by their children when there's some data to transfer,
so they may be suspended for the majority of time and resumed
on demand, when the children have data to send or receive. For this
purpose, however, their power.ignore_children flags have to be set,
or the PM core wouldn't allow them to be suspended while their
children were active.
Unfortunately, in some situations it may take too much time to
resume such devices so that they can assist their children in
transferring data. For example, if such a device belongs to a PM
domain which goes to the "power off" state when that device is
suspended, it may take too much time to restore power to the
domain in response to the request from one of the device's
children. In that case, if the parent's resume time is critical,
the domain should stay in the "power on" state, although it still may
be desirable to power manage the parent itself (e.g. by manipulating
its clock).
In general, device PM QoS may be used to address this problem.
Namely, if the device's children added PM QoS latency constraints
for it, they would be able to prevent it from being put into an
overly deep low-power state. However, in some cases the devices
needing to be serviced are not the immediate children of a
"children-ignoring" device, but its grandchildren or even less
direct descendants. In those cases, the entity wanting to add a
PM QoS request for a given device's ancestor that ignores its
children will have to find it in the first place, so introduce a new
helper function that may be used to achieve that. This function,
dev_pm_qos_add_ancestor_request(), will search for the first
ancestor of the given device whose power.ignore_children flag is
set and will add a device PM QoS latency request for that ancestor
on behalf of the caller. The request added this way may be removed
with the help of dev_pm_qos_remove_request() in the future, like
any other device PM QoS latency request.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Since the PM core is now going to execute driver callbacks directly
if the corresponding subsystem callbacks are not present,
forward-only subsystem callbacks (i.e. such that only execute the
corresponding driver callbacks) are not necessary any more. Thus
it is possible to remove generic_subsys_pm_ops, because the only
callback in there that is not forward-only, .runtime_idle, is not
really used by the only user of generic_subsys_pm_ops, which is
vio_bus_type.
However, the generic callback routines themselves cannot be removed
from generic_ops.c, because they are used individually by a number
of subsystems.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Make the PM core execute driver PM callbacks directly if the
corresponding subsystem callbacks are not present.
There are three reasons for doing that. First, it reflects the
behavior of drivers/base/dd.c:really_probe() that runs the driver's
.probe() callback directly if the bus type's one is not defined, so
this change will remove one arbitrary difference between the PM core
and the remaining parts of the driver core. Second, it will allow
some subsystems, whose PM callbacks don't do anything except for
executing driver callbacks, to be simplified quite a bit by removing
those "forward-only" callbacks. Finally, it will allow us to remove
one level of indirection in the system suspend and resume code paths
where it is not necessary, which is going to lead to less debug noise
with initcall_debug passed in the kernel command line (messages won't
be printed for driverless devices whose subsystems don't provide
PM callbacks among other things).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Make the pm_op() and pm_noirq_op() functions return pointers to
appropriate callbacks instead of executing those callbacks and
returning their results.
This change is required for a subsequent modification that will
execute the corresponding driver callback if the subsystem
callback returned by either pm_op(), or pm_noirq_op() is NULL.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
After the change that removed the code related to runtime PM
from __pm_generic_call() and __pm_generic_resume() these two
functions need not be separate any more, so merge them.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The pm_runtime_suspended() check in __pm_generic_call() doesn't
really help and may cause problems to happen, because in some cases
the system suspend callbacks need to be called even if the given
device has been suspended by runtime PM. For example, if the device
generally supports remote wakeup and is not enabled to wake up
the system from sleep, it should be prevented from generating wakeup
signals during system suspend and that has to be done by the
suspend callbacks that the pm_runtime_suspended() check prevents from
being executed.
Similarly, it may not be a good idea to unconditionally change
the runtime PM status of the device to 'active' in
__pm_generic_resume(), because the driver may want to leave the
device in the 'suspended' state, depending on what happened to it
before the system suspend and whether or not it is enabled to
wake up the system.
For the above reasons, remove the pm_runtime_suspended()
check from __pm_generic_call() and remove the code changing the
device's runtime PM status from __pm_generic_resume().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Since systems are likely to have power domains that can't be turned off
for various reasons at least temporarily while implementing power domain
support provide a default governor which will always refuse to power off
the domain, saving platforms having to implement their own.
Since the code is so tiny don't bother with a Kconfig symbol for it.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Commit d23b9b00cd (PM / Domains: Rework
system suspend callback routines (v2)) broke the system suspend and
resume handling by devices belonging to generic PM domains, because
it used freeze/thaw callbacks instead of suspend/resume ones and
didn't initialize device callbacks for system suspend/resume
properly at all. Fix those problems.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Add a name member pointer to struct generic_pm_domain and use it in
diagnostic messages regarding the domain power-off and power-on
latencies. Update the ARM shmobile SH7372 code to assign names to
the PM domains used by it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
Make pm_op() and pm_noirq_op() use the same helper function for
running callbacks, which will cause them to use the same format of
diagnostic messages. This also reduces the complexity and size of
the code quite a bit.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Measure the time of execution of the .stop(), .start(), .save_state()
and .restore_state() PM domain device callbacks and if the result
is greater than the corresponding latency value stored in the
device's struct generic_pm_domain_data object, replace the inaccurate
value with the measured time.
Do analogously for the PM domains' .power_off() and .power_off()
callbacks.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Add a function deciding whether or not a given PM domain should
be powered off on the basis of the PM QoS constraints of devices
belonging to it and their PM QoS timing data.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Add a function deciding whether or not devices should be stopped in
pm_genpd_runtime_suspend() depending on their PM QoS constraints
and stop/start timing values. Make it possible to add information
used by this function to device objects.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
The current generic PM domains code attempts to use the generic
system suspend operations along with the domains' device stop/start
routines, which requires device drivers to assume that their
system suspend/resume (and hibernation/restore) callbacks will always
be used with generic PM domains. However, in theory, the same
hardware may be used in devices that don't belong to any PM domain,
in which case it would be necessary to add "fake" PM domains to
satisfy the above assumption. Also, the domain the hardware belongs
to may not be handled with the help of the generic code.
To allow device drivers that may be used along with the generic PM
domains code of more flexibility, add new device callbacks,
.suspend(), .suspend_late(), .resume_early(), .resume(), .freeze(),
.freeze_late(), .thaw_early(), and .thaw(), that can be supplied by
the drivers in addition to their "standard" system suspend and
hibernation callbacks. These new callbacks, if defined, will be used
by the generic PM domains code for the handling of system suspend and
hibernation instead of the "standard" ones. This will allow drivers
to be designed to work with generic PM domains as well as without
them.
For backwards compatibility, introduce default implementations of the
new callbacks for PM domains that will execute pm_generic_suspend(),
pm_generic_suspend_noirq(), pm_generic_resume_noirq(),
pm_generic_resume(), pm_generic_freeze(), pm_generic_freeze_noirq(),
pm_generic_thaw_noirq(), and pm_generic_thaw(), respectively, for the
given device if its driver doesn't define those callbacks.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The current PM domains code uses device drivers' .runtime_suspend()
and .runtime_resume() callbacks as the "save device state" and
"restore device state" operations, which may not be appropriate in
general, because it forces drivers to assume that they always will
be used with generic PM domains. However, in theory, the same
hardware may be used in devices that don't belong to any PM
domain, in which case it would be necessary to add "fake" PM
domains to satisfy the above assumption. It also may be located in
a PM domain that's not handled with the help of the generic code.
To allow device drivers that may be used along with the generic PM
domains code of more flexibility, introduce new device callbacks,
.save_state() and .restore_state(), that can be supplied by the
drivers in addition to their "standard" runtime PM callbacks. This
will allow the drivers to be designed to work with generic PM domains
as well as without them.
For backwards compatibility, introduce default .save_state() and
.restore_state() callback routines for PM domains that will execute
a device driver's .runtime_suspend() and .runtime_resume() callbacks,
respectively, for the given device if the driver doesn't provide its
own implementations of .save_state() and .restore_state().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The current generic PM domains code requires that the same .stop(),
.start() and .active_wakeup() device callback routines be used for
all devices in the given domain, which is inflexible and may not
cover some specific use cases. For this reason, make it possible to
use device specific .start()/.stop() and .active_wakeup() callback
routines by adding corresponding callback pointers to struct
generic_pm_domain_data. Add a new helper routine,
pm_genpd_register_callbacks(), that can be used to populate
the new per-device callback pointers.
Modify the shmobile's power domains code to allow drivers to add
their own code to be run during the device stop and start operations
with the help of the new callback pointers.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
Make the runtime PM core use device PM QoS constraints to check if
it is allowed to suspend a given device, so that an error code is
returned if the device's own PM QoS constraint is negative or one of
its children has already been suspended for too long. If this is
not the case, the maximum estimated time the device is allowed to be
suspended, computed as the minimum of the device's PM QoS constraint
and the PM QoS constraints of its children (reduced by the difference
between the current time and their suspend times) is stored in a new
device's PM field power.max_time_suspended_ns that can be used by
the device's subsystem or PM domain to decide whether or not to put
the device into lower-power (and presumably higher-latency) states
later (if the constraint is 0, which means "no constraint", the
power.max_time_suspended_ns is set to -1).
Additionally, the time of execution of the subsystem-level
.runtime_suspend() callback for the device is recorded in the new
power.suspend_time field for later use by the device's subsystem or
PM domain along with power.max_time_suspended_ns (it also is used
by the core code when the device's parent is suspended).
Introduce a new helper function,
pm_runtime_update_max_time_suspended(), allowing subsystems and PM
domains (or device drivers) to update the power.max_time_suspended_ns
field, for example after changing the power state of a suspended
device.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Remove a few if () and return statements in device_suspend_noirq()
that aren't really necessary.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
The "End" label in device_prepare() in drivers/base/power/main.c is
not necessary and the jumps to it have no real effect, so remove them
all.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Commit 4ca46ff3e0 (PM / Sleep: Mark
devices involved in wakeup signaling during suspend) introduced
the power.wakeup_path field in struct dev_pm_info to mark devices
whose children are enabled to wake up the system from sleep states,
so that power domains containing the parents that provide their
children with wakeup power and/or relay their wakeup signals are not
turned off. Unfortunately, that introduced a PM regression on SH7372
whose power consumption in the system "memory sleep" state increased
as a result of it, because it prevented the power domain containing
the I2C controller from being turned off when some children of that
controller were enabled to wake up the system, although the
controller was not necessary for them to signal wakeup.
To fix this issue use the observation that devices whose
power.ignore_children flag is set for runtime PM should be treated
analogously during system suspend. Namely, they shouldn't be
included in wakeup paths going through their children. Since the
SH7372 I2C controller's power.ignore_children flag is set, doing so
will restore the previous behavior of that SOC.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Make dev_pm_qos_add_request() use WARN() in a better way and do not hardcode
the function's name into the message (use __func__ instead).
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Refrain from running clk_disable() on clocks that
have not been enabled. A typical case when this can
happen is during Suspend-to-RAM for devices that have
no driver associated with them. In such case the clock
may be in default ACQUIRED state.
Without this patch the sh7372 Mackerel board crashes
in __clk_disable() during Suspend-to-RAM with:
"Trying to disable clock 0xdeadbeef with 0 usecount"
This happens for the CEU device which is added during
boot. The test case has no CEU driver included in the
kernel configuration. Needed for v3.2-rc1.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...))
[The semantic patch that makes this change is available
in scripts/coccinelle/api/err_cast.cocci.
More information about semantic patching is available at
http://coccinelle.lip6.fr/]
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
Originally, the runtime PM core would send an idle notification
whenever a suspend attempt failed. The idle callback routine could
then schedule a delayed suspend for some time later.
However this behavior was changed by commit
f71648d73c (PM / Runtime: Remove idle
notification after failing suspend). No notifications were sent, and
there was no clear mechanism to retry failed suspends.
This caused problems for the usbhid driver, because it fails
autosuspend attempts as long as a key is being held down. Therefore
this patch (as1492) adds a mechanism for retrying failed
autosuspends. If the callback routine updates the last_busy field so
that the next autosuspend expiration time is in the future, the
autosuspend will automatically be rescheduled.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Henrik Rydberg <rydberg@euromail.se>
Cc: <stable@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
With delta type being int, its value is made zero
for all values of now > 0x80000000.
Hence fixing it.
Signed-off-by: venu byravarasu <vbyravarasu@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This file isn't using full modular functionality, and hence
can be "downgraded" to just using export.h
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Most of these files were implicitly getting EXPORT_SYMBOL via
device.h which was including module.h, but that path will be broken
soon.
[ with input from Stephen Rothwell <sfr@canb.auug.org.au> ]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Since kfree() checks it its argument is not NULL, it is not necessary
to duplicate this check in __pm_clk_remove().
[rjw: Added the changelog.]
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* pm-domains:
ARM: mach-shmobile: sh7372 A4R support (v4)
ARM: mach-shmobile: sh7372 A3SP support (v4)
PM / Sleep: Mark devices involved in wakeup signaling during suspend
The generic PM domains code in drivers/base/power/domain.c has
to avoid powering off domains that provide power to wakeup devices
during system suspend. Currently, however, this only works for
wakeup devices directly belonging to the given domain and not for
their children (or the children of their children and so on).
Thus, if there's a wakeup device whose parent belongs to a power
domain handled by the generic PM domains code, the domain will be
powered off during system suspend preventing the device from
signaling wakeup.
To address this problem introduce a device flag, power.wakeup_path,
that will be set during system suspend for all wakeup devices,
their parents, the parents of their parents and so on. This way,
all wakeup paths in the device hierarchy will be marked and the
generic PM domains code will only need to avoid powering off
domains containing devices whose power.wakeup_path is set.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1485) documents a change to the kernel's default wakeup
policy. Devices that forward wakeup requests between buses should be
enabled for wakeup by default.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Record S3 failure time about each reason and the latest two failed
devices' names in S3 progress.
We can check it through 'suspend_stats' entry in debugfs.
The motivation of the patch:
We are enabling power features on Medfield. Comparing with PC/notebook,
a mobile enters/exits suspend-2-ram (we call it s3 on Medfield) far
more frequently. If it can't enter suspend-2-ram in time, the power
might be used up soon.
We often find sometimes, a device suspend fails. Then, system retries
s3 over and over again. As display is off, testers and developers
don't know what happens.
Some testers and developers complain they don't know if system
tries suspend-2-ram, and what device fails to suspend. They need
such info for a quick check. The patch adds suspend_stats under
debugfs for users to check suspend to RAM statistics quickly.
If not using this patch, we have other methods to get info about
what device fails. One is to turn on CONFIG_PM_DEBUG, but users
would get too much info and testers need recompile the system.
In addition, dynamic debug is another good tool to dump debug info.
But it still doesn't match our utilization scenario closely.
1) user need write a user space parser to process the syslog output;
2) Our testing scenario is we leave the mobile for at least hours.
Then, check its status. No serial console available during the
testing. One is because console would be suspended, and the other
is serial console connecting with spi or HSU devices would consume
power. These devices are powered off at suspend-2-ram.
Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
If .runtime_suspend() returns -EAGAIN or -EBUSY, the device should
still be in ACTIVE state, so it is not necessary to send an idle
notification to its parent. If .runtime_suspend() returns other
fatal failure, it doesn't make sense to send idle notification to
its parent.
Skip parent idle notification when failure is returned from
.runtime_suspend() and update comments in rpm_suspend() to reflect
that change.
[rjw: Modified the subject and changelog slightly.]
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch fix kerneldoc comments for rpm_suspend():
- 'Cancel a pending idle notification' should be put before, also
should be changed to 'Cancel a pending idle notification,
autosuspend or suspend'.
- idle notification for the device after succeeding suspend has
been removed, so update the comment accordingly.
[rjw: Modified the subject and changelog slightly.]
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* pm-domains:
PM / Domains: Split device PM domain data into base and need_restore
ARM: mach-shmobile: sh7372 sleep warning fixes
ARM: mach-shmobile: sh7372 A3SM support
ARM: mach-shmobile: sh7372 generic suspend/resume support
PM / Domains: Preliminary support for devices with power.irq_safe set
PM: Move clock-related definitions and headers to separate file
PM / Domains: Use power.sybsys_data to reduce overhead
PM: Reference counting of power.subsys_data
PM: Introduce struct pm_subsys_data
ARM / shmobile: Make A3RV be a subdomain of A4LC on SH7372
PM / Domains: Rename argument of pm_genpd_add_subdomain()
PM / Domains: Rename GPD_STATE_WAIT_PARENT to GPD_STATE_WAIT_MASTER
PM / Domains: Allow generic PM domains to have multiple masters
PM / Domains: Add "wait for parent" status for generic PM domains
PM / Domains: Make pm_genpd_poweron() always survive parent removal
PM / Domains: Do not take parent locks to modify subdomain counters
PM / Domains: Implement subdomain counters as atomic fields
* pm-runtime:
PM / Tracing: build rpm-traces.c only if CONFIG_PM_RUNTIME is set
PM / Runtime: Replace dev_dbg() with trace_rpm_*()
PM / Runtime: Introduce trace points for tracing rpm_* functions
PM / Runtime: Don't run callbacks under lock for power.irq_safe set
USB: Add wakeup info to debugging messages
PM / Runtime: pm_runtime_idle() can be called in atomic context
PM / Runtime: Add macro to test for runtime PM events
PM / Runtime: Add might_sleep() to runtime PM functions
To read the current PM QoS value for a given device we need to
make sure that the device's power.constraints object won't be
removed while we're doing that. For this reason, put the
operation under dev->power.lock and acquire the lock
around the initialization and removal of power.constraints.
Moreover, since we're using the value of power.constraints to
determine whether or not the object is present, the
power.constraints_state field isn't necessary any more and may be
removed. However, dev_pm_qos_add_request() needs to check if the
device is being removed from the system before allocating a new
PM QoS constraints object for it, so make it use the
power.power_state field of struct device for this purpose.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The patch enables to register notifier_block for an OPP-device in order
to get notified for any changes in the availability of OPPs of the
device. For example, if a new OPP is inserted or enable/disable status
of an OPP is changed, the notifier is executed.
This enables the usage of opp_add, opp_enable, and opp_disable to
directly take effect with any connected entities such as cpufreq or
devfreq.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Mike Turquette <mturquette@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch replaces dev_dbg with trace_rpm_* inside
the three important functions:
rpm_idle
rpm_suspend
rpm_resume
Trace points have the below advantages compared with dev_dbg:
- trace points include much runtime information(such as
running cpu, current task, ...)
- most of linux distributions may disable "verbose debug"
driver debug compile switch, so it is very difficult to
report/debug runtime pm related problems from distribution
users without this kind of debug information.
- for upstream kernel users, enableing the debug switch will
produce many useless "rpm_resume" output, and it is very noise.
- dev_dbg inside rpm_suspend/rpm_resume may have some effects
on runtime pm behaviour of console devicer
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The rpm_suspend() and rpm_resume() routines execute subsystem or PM
domain callbacks under power.lock if power.irq_safe is set for the
given device. This is inconsistent with that rpm_idle() does after
commit 02b2677 (PM / Runtime: Allow _put_sync() from
interrupts-disabled context) and is problematic for subsystems and PM
domains wanting to use power.lock for synchronization in their
runtime PM callbacks.
This change requires the code checking if the device's runtime PM
status is RPM_SUSPENDING or RPM_RESUMING to be modified too, to take
the power.irq_safe set case into account (that code wasn't reachable
before with power.irq_safe set, because it's executed with the
device's power.lock held).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
The struct pm_domain_data data type is defined in such a way that
adding new fields specific to the generic PM domains code will
require include/linux/pm.h to be modified. As a result, data types
used only by the generic PM domains code will be defined in two
headers, although they all should be defined in pm_domain.h and
pm.h will need to include more headers, which won't be very nice.
For this reason change the definition of struct pm_subsys_data
so that its domain_data member is a pointer, which will allow
struct pm_domain_data to be subclassed by various PM domains
implementations. Remove the need_restore member from
struct pm_domain_data and make the generic PM domains code
subclass it by adding the need_restore member to the new data type.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Merge commit e8b364b88c
(PM / Clocks: Do not acquire a mutex under a spinlock) fixing
a regression in drivers/base/power/clock_ops.c.
Conflicts:
drivers/base/power/clock_ops.c
Commit b7ab83e (PM: Use spinlock instead of mutex in clock
management functions) introduced a regression causing clocks_mutex
to be acquired under a spinlock. This happens because
pm_clk_suspend() and pm_clk_resume() call pm_clk_acquire() under
pcd->lock, but pm_clk_acquire() executes clk_get() which causes
clocks_mutex to be acquired. Similarly, __pm_clk_remove(),
executed under pcd->lock, calls clk_put(), which also causes
clocks_mutex to be acquired.
To fix those problems make pm_clk_add() call pm_clk_acquire(), so
that pm_clk_suspend() and pm_clk_resume() don't have to do that.
Change pm_clk_remove() and pm_clk_destroy() to separate
modifications of the pcd->clock_list list from the actual removal of
PM clock entry objects done by __pm_clk_remove().
Reported-and-tested-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
The generic PM domains framework currently doesn't work with devices
whose power.irq_safe flag is set, because runtime PM callbacks for
such devices are run with interrupts disabled and the callbacks
provided by the generic PM domains framework use domain mutexes
and may sleep. However, such devices very well may belong to
power domains on some systems, so the generic PM domains framework
should take them into account.
For this reason, modify the generic PM domains framework so that the
domain .power_off() and .power_on() callbacks are never executed for
a domain containing devices with power.irq_safe set, although the
.stop_device() and .start_device() callbacks are still run for them.
Additionally, introduce a flag allowing the creator of a
struct generic_pm_domain object to indicate that its .stop_device()
and .start_device() callbacks may be run in interrupt context
(might_sleep_if() triggers if that flag is not set and one of those
callbacks is run in interrupt context).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Add a global notification chain that gets called upon changes to the
aggregated constraint value for any device.
The notification callbacks are passing the full constraint request data
in order for the callees to have access to it. The current use is for the
platform low-level code to access the target device of the constraint.
Signed-off-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Implement the per-device PM QoS constraints by creating a device
PM QoS API, which calls the PM QoS constraints management core code.
The per-device latency constraints data strctures are stored
in the device dev_pm_info struct.
The device PM code calls the init and destroy of the per-device constraints
data struct in order to support the dynamic insertion and removal of the
devices in the system.
To minimize the data usage by the per-device constraints, the data struct
is only allocated at the first call to dev_pm_qos_add_request.
The data is later free'd when the device is removed from the system.
A global mutex protects the constraints users from the data being
allocated and free'd.
Signed-off-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Since the PM clock management code in drivers/base/power/clock_ops.c
is used for both runtime PM and system suspend/hibernation, the
definitions of data structures and headers related to it should not
be located in include/linux/pm_rumtime.h. Move them to a separate
header file.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Currently pm_genpd_runtime_resume() has to walk the list of devices
from the device's PM domain to find the corresponding device list
object containing the need_restore field to check if the driver's
.runtime_resume() callback should be executed for the device.
This is suboptimal and can be simplified by using power.sybsys_data
to store device information used by the generic PM domains code.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Since the power.subsys_data device field will be used by multiple
filesystems, introduce a reference counting mechanism for it to avoid
freeing it prematurely or changing its value at a wrong time.
Make the PM clocks management code that currently is the only user of
power.subsys_data use the new reference counting.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Introduce struct pm_subsys_data that may be subclassed by subsystems
to store subsystem-specific information related to the device. Move
the clock management fields accessed through the power.subsys_data
pointer in struct device to the new strucutre.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Change the name of the second argument of pm_genpd_add_subdomain()
so that it is (a) shorter and (b) in agreement with the name of
the second argument of pm_genpd_add_subdomain().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Since it is now possible for a PM domain to have multiple masters
instead of one parent, rename the "wait for parent" status to reflect
the new situation.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Currently, for a given generic PM domain there may be only one parent
domain (i.e. a PM domain it depends on). However, there is at least
one real-life case in which there should be two parents (masters) for
one PM domain (the A3RV domain on SH7372 turns out to depend on the
A4LC domain and it depends on the A4R domain and the same time). For
this reason, allow a PM domain to have multiple parents (masters) by
introducing objects representing links between PM domains.
The (logical) links between PM domains represent relationships in
which one domain is a master (i.e. it is depended on) and another
domain is a slave (i.e. it depends on the master) with the rule that
the slave cannot be powered on if the master is not powered on and
the master cannot be powered off if the slave is not powered off.
Each struct generic_pm_domain object representing a PM domain has
two lists of links, a list of links in which it is a master and
a list of links in which it is a slave. The first of these lists
replaces the list of subdomains and the second one is used in place
of the parent pointer.
Each link is represented by struct gpd_link object containing
pointers to the master and the slave and two struct list_head
members allowing it to hook into two lists (the master's list
of "master" links and the slave's list of "slave" links). This
allows the code to get to the link from each side (either from
the master or from the slave) and follow it in each direction.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The next patch will make it possible for a generic PM domain to have
multiple parents (i.e. multiple PM domains it depends on). To
prepare for that change it is necessary to change pm_genpd_poweron()
so that it doesn't jump to the start label after running itself
recursively for the parent domain. For this purpose, introduce a new
PM domain status value GPD_STATE_WAIT_PARENT that will be set by
pm_genpd_poweron() before calling itself recursively for the parent
domain and modify the code in drivers/base/power/domain.c so that
the GPD_STATE_WAIT_PARENT status is guaranteed to be preserved during
the execution of pm_genpd_poweron() for the parent.
This change also causes pm_genpd_add_subdomain() and
pm_genpd_remove_subdomain() to wait for started pm_genpd_poweron() to
complete and allows pm_genpd_runtime_resume() to avoid dropping the
lock after powering on the PM domain.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
If pm_genpd_remove_subdomain() is called to remove a PM domain's
subdomain and pm_genpd_poweron() is called for that subdomain at
the same time, and the pm_genpd_poweron() called by it recursively
for the parent returns an error, the first pm_genpd_poweron()'s
error code path will attempt to decrement the subdomain counter of
a PM domain that it's not a subdomain of any more.
Rearrange the code in pm_genpd_poweron() to prevent this from
happening.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
After the subdomain counter in struct generic_pm_domain has been
changed into an atomic_t field, it is possible to modify
pm_genpd_poweron() and pm_genpd_poweroff() so that they don't take
the parents locks. This requires pm_genpd_poweron() to increment
the parent's subdomain counter before calling itself recursively
for the parent and to decrement it if an error is to be returned.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Currently, pm_genpd_poweron() and pm_genpd_poweroff() need to take
the parent PM domain's lock in order to modify the parent's counter
of active subdomains in a nonracy way. This causes the locking to be
considerably complex and in fact is not necessary, because the
subdomain counters may be implemented as atomic fields and they
won't have to be modified under a lock.
Replace the unsigned in sd_count field in struct generic_pm_domain
by an atomic_t one and modify the code in drivers/base/power/domain.c
to take this change into account.
This patch doesn't change the locking yet, that is going to be done
in a separate subsequent patch.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The lock member of struct pm_clk_data is of type struct mutex,
which is a problem, because the suspend and resume routines
defined in drivers/base/power/clock_ops.c cannot be executed
with interrupts disabled for this reason. Modify
struct pm_clk_data so that its lock member is a spinlock.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
Some of the entry points to pm runtime are not safe to
call in atomic context unless pm_runtime_irq_safe() has
been called. Inspecting the code, it is not immediately
obvious that the functions sleep at all, as they run
inside a spin_lock_irqsave, but under some conditions
they can drop the lock and turn on irqs.
If a driver incorrectly calls the pm_runtime apis, it can
cause sleeping and irq processing when it expects to stay
in atomic context.
Add might_sleep_if to the majority of the __pm_runtime_* entry points
to enforce correct usage.
Add pm_runtime_put_sync_autosuspend to the list of
functions that can be called in atomic context.
Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Function genpd_queue_power_off_work() is not defined for
CONFIG_PM_RUNTIME, so pm_genpd_poweroff_unused() causes a build
error to happen in that case. Fix the problem by making
pm_genpd_poweroff_unused() depend on CONFIG_PM_RUNTIME too.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Currently the use of pm_runtime_put_sync() is not safe from
interrupts-disabled context because rpm_idle() will release the
spinlock and enable interrupts for the idle callbacks. This enables
interrupts during a time where interrupts were expected to be
disabled, and can have strange side effects on drivers that expected
interrupts to be disabled.
This is not a bug since the documentation clearly states that only
_put_sync_suspend() is safe in IRQ-safe mode.
However, pm_runtime_put_sync() could be made safe when in IRQ-safe
mode by releasing the spinlock but not re-enabling interrupts, which
is what this patch aims to do.
Problem was found when using some buggy drivers that set
pm_runtime_irq_safe() and used _put_sync() in interrupts-disabled
context.
Reported-by: Colin Cross <ccross@google.com>
Tested-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The local variable ret is defined twice in pm_genpd_poweron(), which
causes this function to always return 0, even if the PM domain's
.power_on() callback fails, in which case an error code should be
returned.
Remove the wrong second definition of ret and additionally remove an
unnecessary definition of wait from pm_genpd_poweron().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dev_opp initial value shoule be ERR_PTR(), IS_ERR() is used to check
error.
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pm-runtime:
OMAP: PM: disable idle on suspend for GPIO and UART
OMAP: PM: omap_device: add API to disable idle on suspend
OMAP: PM: omap_device: add system PM methods for PM domain handling
OMAP: PM: omap_device: conditionally use PM domain runtime helpers
PM / Runtime: Add new helper function: pm_runtime_status_suspended()
PM / Runtime: Consistent utilization of deferred_resume
PM / Runtime: Prevent runtime_resume from racing with probe
PM / Runtime: Replace "run-time" with "runtime" in documentation
PM / Runtime: Improve documentation of enable, disable and barrier
PM: Limit race conditions between runtime PM and system sleep (v2)
PCI / PM: Detect early wakeup in pci_pm_prepare()
PM / Runtime: Return special error code if runtime PM is disabled
PM / Runtime: Update documentation of interactions with system sleep
* pm-domains: (33 commits)
ARM / shmobile: Return -EBUSY from A4LC power off if A3RV is active
PM / Domains: Take .power_off() error code into account
ARM / shmobile: Use genpd_queue_power_off_work()
ARM / shmobile: Use pm_genpd_poweroff_unused()
PM / Domains: Introduce function to power off all unused PM domains
PM / Domains: Queue up power off work only if it is not pending
PM / Domains: Improve handling of wakeup devices during system suspend
PM / Domains: Do not restore all devices on power off error
PM / Domains: Allow callbacks to execute all runtime PM helpers
PM / Domains: Do not execute device callbacks under locks
PM / Domains: Make failing pm_genpd_prepare() clean up properly
PM / Domains: Set device state to "active" during system resume
ARM: mach-shmobile: sh7372 A3RV requires A4LC
PM / Domains: Export pm_genpd_poweron() in header
ARM: mach-shmobile: sh7372 late pm domain off
ARM: mach-shmobile: Runtime PM late init callback
ARM: mach-shmobile: sh7372 D4 support
ARM: mach-shmobile: sh7372 A4MP support
ARM: mach-shmobile: sh7372: make sure that fsi is peripheral of spu2
ARM: mach-shmobile: sh7372 A3SG support
...
Some users are apparently confused by dmesg output from
read_magic_time(), which looks like "real" time and date.
Add the "RTC" string to time stamps printed by read_magic_time() to
avoid that confusion.
Reported-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
cpufreq table allocated by opp_init_cpufreq_table is better
freed by OPP layer itself. This allows future modifications to
the table handling to be transparent to the users.
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Currently pm_genpd_poweroff() discards error codes returned by
the PM domain's .power_off() callback, because it's safer to always
regard the domain as inaccessible to drivers after a failing
.power_off(). Still, there are situations in which the low-level
code may want to indicate that it doesn't want to power off the
domain, so allow it to do that by returning -EBUSY from .power_off().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
Make pd_power_down_a3rv() use genpd_queue_power_off_work() to queue
up the powering off of the A4LC domain to avoid queuing it up when
it is pending.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
Add a new function pm_genpd_poweroff_unused() queuing up the
execution of pm_genpd_poweroff() for every initialized generic PM
domain. Calling it will cause every generic PM domain without
devices in use to be powered off.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
In theory it is possible that pm_genpd_poweroff() for two different
subdomains of the same parent domain will attempt to queue up the
execution of pm_genpd_poweroff() for the parent twice in a row. This
would lead to unpleasant consequences, so prevent it from happening
by checking if genpd->power_off_work is pending before attempting to
queue it up.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Kevin points out that if there's a device that can wake up the system
from sleep states, but it doesn't generate wakeup signals by itself
(they are generated on its behalf by other parts of the system) and
it currently is not enabled to wake up the system (that is,
device_may_wakeup() returns "false" for it), we may need to change
its wakeup settings during system suspend (for example, the device
might have been configured to signal remote wakeup from the system's
working state, as needed by runtime PM). Therefore the generic PM
domains code should invoke the system suspend callbacks provided by
the device's driver, which it doesn't do if the PM domain is powered
off during the system suspend's "prepare" stage. This is a valid
point. Moreover, this code also should make sure that system wakeup
devices that are enabled to wake up the system from sleep states and
have to remain active for this purpose are not suspended while the
system is in a sleep state.
To avoid the above issues, make the generic PM domains' .prepare()
routine, pm_genpd_prepare(), force runtime resume of devices whose
system wakeup settings may need to be changed during system suspend
or that should remain active while the system is in a sleep state to
be able to wake it up from that state.
Reported-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Since every device in a PM domain has its own need_restore
flag, which is set by __pm_genpd_save_device(), there's no need to
walk the domain's device list and restore all devices on an error
from one of the drivers' .runtime_suspend() callbacks.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
A deadlock may occur if one of the PM domains' .start_device() or
.stop_device() callbacks or a device driver's .runtime_suspend() or
.runtime_resume() callback executed by the core generic PM domain
code uses a "wrong" runtime PM helper function. This happens, for
example, if .runtime_resume() from one device's driver calls
pm_runtime_resume() for another device in the same PM domain.
A similar situation may take place if a device's parent is in the
same PM domain, in which case the runtime PM framework may execute
pm_genpd_runtime_resume() automatically for the parent (if it is
suspended at the moment). This, of course, is undesirable, so
the generic PM domains code should be modified to prevent it from
happening.
The runtime PM framework guarantees that pm_genpd_runtime_suspend()
and pm_genpd_runtime_resume() won't be executed in parallel for
the same device, so the generic PM domains code need not worry
about those cases. Still, it needs to prevent the other possible
race conditions between pm_genpd_runtime_suspend(),
pm_genpd_runtime_resume(), pm_genpd_poweron() and pm_genpd_poweroff()
from happening and it needs to avoid deadlocks at the same time.
To this end, modify the generic PM domains code to relax
synchronization rules so that:
* pm_genpd_poweron() doesn't wait for the PM domain status to
change from GPD_STATE_BUSY. If it finds that the status is
not GPD_STATE_POWER_OFF, it returns without powering the domain on
(it may modify the status depending on the circumstances).
* pm_genpd_poweroff() returns as soon as it finds that the PM
domain's status changed from GPD_STATE_BUSY after it's released
the PM domain's lock.
* pm_genpd_runtime_suspend() doesn't wait for the PM domain status
to change from GPD_STATE_BUSY after executing the domain's
.stop_device() callback and executes pm_genpd_poweroff() only
if pm_genpd_runtime_resume() is not executed in parallel.
* pm_genpd_runtime_resume() doesn't wait for the PM domain status
to change from GPD_STATE_BUSY after executing pm_genpd_poweron()
and sets the domain's status to GPD_STATE_BUSY and increments its
counter of resuming devices (introduced by this change) immediately
after acquiring the lock. The counter of resuming devices is then
decremented after executing __pm_genpd_runtime_resume() for the
device and the domain's status is reset to GPD_STATE_ACTIVE (unless
there are more resuming devices in the domain, in which case the
status remains GPD_STATE_BUSY).
This way, for example, if a device driver's .runtime_resume()
callback executes pm_runtime_resume() for another device in the same
PM domain, pm_genpd_poweron() called by pm_genpd_runtime_resume()
invoked by the runtime PM framework will not block and it will see
that there's nothing to do for it. Next, the PM domain's lock will
be acquired without waiting for its status to change from
GPD_STATE_BUSY and the device driver's .runtime_resume() callback
will be executed. In turn, if pm_runtime_suspend() is executed by
one device driver's .runtime_resume() callback for another device in
the same PM domain, pm_genpd_poweroff() executed by
pm_genpd_runtime_suspend() invoked by the runtime PM framework as a
result will notice that one of the devices in the domain is being
resumed, so it will return immediately.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Currently, the .start_device() and .stop_device() callbacks from
struct generic_pm_domain() as well as the device drivers' runtime PM
callbacks used by the generic PM domains code are executed under
the generic PM domain lock. This, unfortunately, is prone to
deadlocks, for example if a device and its parent are boths members
of the same PM domain. For this reason, it would be better if the
PM domains code didn't execute device callbacks under the lock.
Rework the locking in the generic PM domains code so that the lock
is dropped for the execution of device callbacks. To this end,
introduce PM domains states reflecting the current status of a PM
domain and such that the PM domain lock cannot be acquired if the
status is GPD_STATE_BUSY. Make threads attempting to acquire a PM
domain's lock wait until the status changes to either
GPD_STATE_ACTIVE or GPD_STATE_POWER_OFF.
This change by itself doesn't fix the deadlock problem mentioned
above, but the mechanism introduced by it will be used for for this
purpose by a subsequent patch.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
If pm_generic_prepare() in pm_genpd_prepare() returns error code,
the PM domains counter of "prepared" devices should be decremented
and its suspend_power_off flag should be reset if this counter drops
down to zero. Otherwise, the PM domain runtime PM code will not
handle the domain correctly (it will permanently think that system
suspend is in progress).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The runtime PM status of devices in a power domain that is not
powered off in pm_genpd_complete() should be set to "active", because
those devices are operational at this point. Some of them may not be
in use, though, so make pm_genpd_complete() call pm_runtime_idle()
in addition to pm_runtime_set_active() for each of them.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
dev->power.deferred_resume is used as a bool typically, so change
one assignment to false from 0, like other places.
Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
This patch (as1475) adds device_lock() and device_unlock() calls to
the store methods for the power/control and power/autosuspend_delay_ms
sysfs attribute files. We don't want badly timed writes to these
files to cause runtime_resume callbacks to occur while a driver is
being probed for a device.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The runtime PM documentation and kerneldoc comments sometimes spell
"runtime" with a dash (i.e. "run-time"). Replace all of those
instances with "runtime" to make the naming consistent.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
One of the roles of the PM core is to prevent different PM callbacks
executed for the same device object from racing with each other.
Unfortunately, after commit e866500247
(PM: Allow pm_runtime_suspend() to succeed during system suspend)
runtime PM callbacks may be executed concurrently with system
suspend/resume callbacks for the same device.
The main reason for commit e866500247
was that some subsystems and device drivers wanted to use runtime PM
helpers, pm_runtime_suspend() and pm_runtime_put_sync() in
particular, for carrying out the suspend of devices in their
.suspend() callbacks. However, as it's been determined recently,
there are multiple reasons not to do so, inlcuding:
* The caller really doesn't control the runtime PM usage counters,
because user space can access them through sysfs and effectively
block runtime PM. That means using pm_runtime_suspend() or
pm_runtime_get_sync() to suspend devices during system suspend
may or may not work.
* If a driver calls pm_runtime_suspend() from its .suspend()
callback, it causes the subsystem's .runtime_suspend() callback to
be executed, which leads to the call sequence:
subsys->suspend(dev)
driver->suspend(dev)
pm_runtime_suspend(dev)
subsys->runtime_suspend(dev)
recursive from the subsystem's point of view. For some subsystems
that may actually work (e.g. the platform bus type), but for some
it will fail in a rather spectacular fashion (e.g. PCI). In each
case it means a layering violation.
* Both the subsystem and the driver can provide .suspend_noirq()
callbacks for system suspend that can do whatever the
.runtime_suspend() callbacks do just fine, so it really isn't
necessary to call pm_runtime_suspend() during system suspend.
* The runtime PM's handling of wakeup devices is usually different
from the system suspend's one, so .runtime_suspend() may simply be
inappropriate for system suspend.
* System suspend is supposed to work even if CONFIG_PM_RUNTIME is
unset.
* The runtime PM workqueue is frozen before system suspend, so if
whatever the driver is going to do during system suspend depends
on it, that simply won't work.
Still, there is a good reason to allow pm_runtime_resume() to
succeed during system suspend and resume (for instance, some
subsystems and device drivers may legitimately use it to ensure that
their devices are in full-power states before suspending them).
Moreover, there is no reason to prevent runtime PM callbacks from
being executed in parallel with the system suspend/resume .prepare()
and .complete() callbacks and the code removed by commit
e866500247 went too far in this
respect. On the other hand, runtime PM callbacks, including
.runtime_resume(), must not be executed during system suspend's
"late" stage of suspending devices and during system resume's "early"
device resume stage.
Taking all of the above into consideration, make the PM core
acquire a runtime PM reference to every device and resume it if
there's a runtime PM resume request pending right before executing
the subsystem-level .suspend() callback for it. Make the PM core
drop references to all devices right after executing the
subsystem-level .resume() callbacks for them. Additionally,
make the PM core disable the runtime PM framework for all devices
during system suspend, after executing the subsystem-level .suspend()
callbacks for them, and enable the runtime PM framework for all
devices during system resume, right before executing the
subsystem-level .resume() callbacks for them.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
Some callers of pm_runtime_get_sync() and other runtime PM helper
functions, scsi_autopm_get_host() and scsi_autopm_get_device() in
particular, need to distinguish error codes returned when runtime PM
is disabled (i.e. power.disable_depth is nonzero for the given
device) from error codes returned in other situations. For this
reason, make the runtime PM helper functions return -EACCES when
power.disable_depth is nonzero and ensure that this error code
won't be returned by them in any other circumstances. Modify
scsi_autopm_get_host() and scsi_autopm_get_device() to check the
error code returned by pm_runtime_get_sync() and ignore -EACCES.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The common PM clock management functions may be used for system
suspend/resume as well as for runtime PM, so rename them
accordingly. Modify kerneldoc comments describing these functions
and kernel messages printed by them, so that they refer to power
management in general rather that to runtime PM.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Kevin Hilman <khilman@ti.com>
The common clocks management code in drivers/base/power/clock_ops.c
is going to be used during system-wide power transitions as well as
for runtime PM, so it shouldn't depend on CONFIG_PM_RUNTIME.
However, the suspend/resume functions provided by it for
CONFIG_PM_RUNTIME unset, to be used during system-wide power
transitions, should not behave in the same way as their counterparts
defined for CONFIG_PM_RUNTIME set, because in that case the clocks
are managed differently at run time.
The names of the functions still contain the word "runtime" after
this change, but that is going to be modified by a separate patch
later.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Kevin Hilman <khilman@ti.com>
There is the problem how to handle devices set up to wake up the
system from sleep states during system-wide power transitions.
In some cases, those devices can be turned off entirely, because the
wakeup signals will be generated on their behalf anyway. In some
other cases, they will generate wakeup signals if their clocks are
stopped, but only if power is not removed from them. Finally, in
some cases, they can only generate wakeup signals if power is not
removed from them and their clocks are enabled.
To allow platform-specific code to decide whether or not to put
wakeup devices (and their PM domains) into low-power state during
system-wide transitions, such as system suspend, introduce a new
generic PM domain callback, .active_wakeup(), that will be used
during the "noirq" phase of system suspend and hibernation (after
image creation) to decide what to do with wakeup devices.
Specifically, if this callback is present and returns "true", the
generic PM domain code will not execute .stop_device() for the
given wakeup device and its PM domain won't be powered off.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
Make generic PM domains support system-wide power transitions
(system suspend and hibernation). Add suspend, resume, freeze, thaw,
poweroff and restore callbacks to be associated with struct
generic_pm_domain objects and make pm_genpd_init() use them as
appropriate.
The new callbacks do nothing for devices belonging to power domains
that were powered down at run time (before the transition). For the
other devices the action carried out depends on the type of the
transition. During system suspend the power domain .suspend()
callback executes pm_generic_suspend() for the device, while the
PM domain .suspend_noirq() callback runs pm_generic_suspend_noirq()
for it, stops it and eventually removes power from the PM domain it
belongs to (after all devices in the domain have been stopped and its
subdomains have been powered off).
During system resume the PM domain .resume_noirq() callback
restores power to the PM domain (when executed for it first time),
starts the device and executes pm_generic_resume_noirq() for it,
while the .resume() callback executes pm_generic_resume() for the
device. Finally, the .complete() callback executes pm_runtime_idle()
for the device which should put it back into the suspended state if
its runtime PM usage count is equal to zero at that time.
The actions carried out during hibernation and resume from it are
analogous to the ones described above.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Kevin Hilman <khilman@ti.com>
There is some code in drivers/base/power/domain.c that will be useful
for both runtime PM and system-wide power transitions, so make it
depend on CONFIG_PM instead of CONFIG_PM_RUNTIME.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Introduce generic "noirq" power management callback routines for
subsystems in addition to the "regular" generic PM callback routines.
The new routines will be used, among other things, for implementing
system-wide PM transitions support for generic PM domains.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Introduce common headers, helper functions and callbacks allowing
platforms to use simple generic power domains for runtime power
management.
Introduce struct generic_pm_domain to be used for representing
power domains that each contain a number of devices and may be
parent domains or subdomains with respect to other power domains.
Among other things, this structure includes callbacks to be
provided by platforms for performing specific tasks related to
power management (i.e. ->stop_device() may disable a device's
clocks, while ->start_device() may enable them, ->power_off() is
supposed to remove power from the entire power domain
and ->power_on() is supposed to restore it).
Introduce functions that can be used as power domain runtime PM
callbacks, pm_genpd_runtime_suspend() and pm_genpd_runtime_resume(),
as well as helper functions for the initialization of a power
domain represented by a struct generic_power_domain object,
adding a device to or removing a device from it and adding or
removing subdomains.
Introduce configuration option CONFIG_PM_GENERIC_DOMAINS to be
selected by the platforms that want to use the new code.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: Kevin Hilman <khilman@ti.com>
The naming convention used by commit 7538e3db6e015e890825fbd9f86599b
(PM: Add support for device power domains), which introduced the
struct dev_power_domain type for representing device power domains,
evidently confuses some developers who tend to think that objects
of this type must correspond to "power domains" as defined by
hardware, which is not the case. Namely, at the kernel level, a
struct dev_power_domain object can represent arbitrary set of devices
that are mutually dependent power management-wise and need not belong
to one hardware power domain. To avoid that confusion, rename struct
dev_power_domain to struct dev_pm_domain and rename the related
pointers in struct device and struct pm_clk_notifier_block from
pwr_domain to pm_domain.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
Commit 85eb8c8d0b (PM / Runtime:
Generic clock manipulation rountines for runtime PM (v6)) converted
the shmobile platform to using generic code for runtime PM clock
management, but it changed the behavior for CONFIG_PM_RUNTIME unset
incorrectly.
Specifically, for CONFIG_PM_RUNTIME unset pm_runtime_clk_notify()
should enable clocks for action equal to BUS_NOTIFY_BIND_DRIVER and
it should disable them for action equal to BUS_NOTIFY_UNBOUND_DRIVER
(instead of BUS_NOTIFY_ADD_DEVICE and BUS_NOTIFY_DEL_DEVICE,
respectively). Make this function behave as appropriate.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
The PM core doesn't handle suspend failures correctly when it comes to
asynchronously suspended devices. These devices are moved onto the
dpm_suspended_list as soon as the corresponding async thread is
started up, and they remain on the list even if they fail to suspend
or the sleep transition is cancelled before they get suspended. As a
result, when the PM core unwinds the transition, it tries to resume
the devices even though they were never suspended.
This patch (as1474) fixes the problem by adding a new "is_suspended"
flag to dev_pm_info. Devices are resumed only if the flag is set.
[rjw:
* Moved the dev->power.is_suspended check into device_resume(),
because we need to complete dev->power.completion and clear
dev->power.is_prepared too for devices whose
dev->power.is_suspended flags are unset.
* Fixed __device_suspend() to avoid setting dev->power.is_suspended
if async_error is different from zero.]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@kernel.org
This patch (as1473) renames the "in_suspend" field in struct
dev_pm_info to "is_prepared", in preparation for an upcoming change.
The new name is more descriptive of what the field really means.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@kernel.org
The loops over connection ID strings in pm_runtime_clk_notify()
should actually iterate over the strings and not over the elements
of the first of them, so make them behave as appropriate.
This fixes a regression introduced by commit 600b776eb3
(OMAP1 / PM: Use generic clock manipulation routines for runtime PM).
Reported-and-tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Introduce generic .prepare() and .complete() power management
callbacks, currently missing, that can be used by subsystems and
power domains and export them. Provide NULL definitions of all
the generic system sleep callbacks for CONFIG_PM_SLEEP unset.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
If device drivers allocate substantial amounts of memory (above 1 MB)
in their hibernate .freeze() callbacks (or in their legacy suspend
callbcks during hibernation), the subsequent creation of hibernate
image may fail due to the lack of memory. This is the case, because
the drivers' .freeze() callbacks are executed after the hibernate
memory preallocation has been carried out and the preallocated amount
of memory may be too small to cover the new driver allocations.
Unfortunately, the drivers' .prepare() callbacks also are executed
after the hibernate memory preallocation has completed, so they are
not suitable for allocating additional memory either. Thus the only
way a driver can safely allocate memory during hibernation is to use
a hibernate/suspend notifier. However, the notifiers are called
before the freezing of user space and the drivers wanting to use them
for allocating additional memory may not know how much memory needs
to be allocated at that point.
To let device drivers overcome this difficulty rework the hibernation
sequence so that the memory preallocation is carried out after the
drivers' .prepare() callbacks have been executed, so that the
.prepare() callbacks can be used for allocating additional memory
to be used by the drivers' .freeze() callbacks. Update documentation
to match the new behavior of the code.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Now that we have CONFIG_DYNAMIC_DEBUG there is no need for yet
another flag causing dev_dbg() and pr_debug() statements in the
core PM code to produce output. Moreover, CONFIG_PM_VERBOSE
causes so much output to be generated that it's not really useful
and almost no one sets it.
References: https://bugzilla.kernel.org/show_bug.cgi?id=23182
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* power-domains:
PM: Fix build issue in clock_ops.c for CONFIG_PM_RUNTIME unset
PM: Revert "driver core: platform_bus: allow runtime override of dev_pm_ops"
OMAP1 / PM: Use generic clock manipulation routines for runtime PM
PM / Runtime: Generic clock manipulation rountines for runtime PM (v6)
PM / Runtime: Add subsystem data field to struct dev_pm_info
OMAP2+ / PM: move runtime PM implementation to use device power domains
PM / Platform: Use generic runtime PM callbacks directly
shmobile: Use power domains for platform runtime PM
PM: Export platform bus type's default PM callbacks
PM: Make power domain callbacks take precedence over subsystem ones
wakeup_source_add() adds an item into wakeup_sources list.
There is no need to call synchronize_rcu() at this point.
Its only needed in wakeup_source_remove()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The "wakeup" device sysfs file is only created if CONFIG_PM_SLEEP
is set, so put it under CONFIG_PM_SLEEP and make a build warning
related to it go away.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Many different platforms and subsystems may want to disable device
clocks during suspend and enable them during resume which is going to
be done in a very similar way in all those cases. For this reason,
provide generic routines for the manipulation of device clocks during
suspend and resume.
Convert the ARM shmobile platform to using the new routines.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Change the PM core's behavior related to power domains in such a way
that, if a power domain is defined for a given device, its callbacks
will be executed instead of and not in addition to the device
subsystem's PM callbacks.
The idea behind the initial implementation of power domains handling
by the PM core was that power domain callbacks would be executed in
addition to subsystem callbacks, so that it would be possible to
extend the subsystem callbacks by using power domains. It turns out,
however, that this wouldn't be really convenient in some important
situations.
For example, there are systems in which power can only be removed
from entire power domains. On those systems it is not desirable to
execute device drivers' PM callbacks until it is known that power is
going to be removed from the devices in question, which means that
they should be executed by power domain callbacks rather then by
subsystem (e.g. bus type) PM callbacks, because subsystems generally
have no information about what devices belong to which power domain.
Thus, for instance, if the bus type in question is the platform bus
type, its PM callbacks generally should not be called in addition to
power domain callbacks, because they run device drivers' callbacks
unconditionally if defined.
While in principle the default subsystem PM callbacks, or a subset of
them, may be replaced with different functions, it doesn't seem
correct to do so, because that would change the subsystem's behavior
with respect to all devices in the system, regardless of whether or
not they belong to any power domains. Thus, the only remaining
option is to make power domain callbacks take precedence over
subsystem callbacks.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Kevin Hilman <khilman@ti.com>
It turns out that some PCI devices are only found to be
wakeup-capable during registration, in which case, when
device_set_wakeup_capable() is called, device_is_registered() already
returns 'true' for the given device, but dpm_sysfs_add() hasn't been
called for it yet. This leads to situations in which the device's
power.can_wakeup flag is not set as requested because of failing
wakeup_sysfs_add() and its wakeup-related sysfs files are not
created, although they should be present. This is a post-2.6.38
regression introduced by commit cb8f51bdad
(PM: Do not create wakeup sysfs files for devices that cannot wake
up).
To work around this problem initialize the device's power.entry
field to an empty list head and make device_set_wakeup_capable()
check if it is still empty before attempting to add the devices
wakeup-related sysfs files with wakeup_sysfs_add(). Namely, if
power.entry is still empty at this point, device_pm_add() hasn't been
called yet for the device and its wakeup-related files will be
created later, so device_set_wakeup_capable() doesn't have to create
them.
Reported-and-tested-by: Tino Keitel <tino.keitel@tikei.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Xen save/restore is going to use hibernate device callbacks for
quiescing devices and putting them back to normal operations and it
would need to select CONFIG_HIBERNATION for this purpose. However,
that also would cause the hibernate interfaces for user space to be
enabled, which might confuse user space, because the Xen kernels
don't support hibernation. Moreover, it would be wasteful, as it
would make the Xen kernels include a substantial amount of code that
they would never use.
To address this issue introduce new power management Kconfig option
CONFIG_HIBERNATE_CALLBACKS, such that it will only select the code
that is necessary for the hibernate device callbacks to work and make
CONFIG_HIBERNATION select it. Then, Xen save/restore will be able to
select CONFIG_HIBERNATE_CALLBACKS without dragging the entire
hibernate code along with it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
opp_find_freq_exact() documentation has is_available instead
of available. This also fixes warning with the kernel-doc:
scripts/kernel-doc drivers/base/power/opp.c >/dev/null
Warning(drivers/base/power/opp.c:246): No description found for parameter 'available'
Warning(drivers/base/power/opp.c:246): Excess function parameter 'is_available' description in 'opp_find_freq_exact'
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The code handling system-wide power transitions (eg. suspend-to-RAM)
can in theory execute callbacks provided by the device's bus type,
device type and class in each phase of the power transition. In
turn, the runtime PM core code only calls one of those callbacks at
a time, preferring bus type callbacks to device type or class
callbacks and device type callbacks to class callbacks.
It seems reasonable to make them both behave in the same way in that
respect. Moreover, even though a device may belong to two subsystems
(eg. bus type and device class) simultaneously, in practice power
management callbacks for system-wide power transitions are always
provided by only one of them (ie. if the bus type callbacks are
defined, the device class ones are not and vice versa). Thus it is
possible to modify the code handling system-wide power transitions
so that it follows the core runtime PM code (ie. treats the
subsystem callbacks as mutually exclusive).
On the other hand, the core runtime PM code will choose to execute,
for example, a runtime suspend callback provided by the device type
even if the bus type's struct dev_pm_ops object exists, but the
runtime_suspend pointer in it happens to be NULL. This is confusing,
because it may lead to the execution of callbacks from different
subsystems during different operations (eg. the bus type suspend
callback may be executed during runtime suspend of the device, while
the device type callback will be executed during system suspend).
Make all of the power management code treat subsystem callbacks in
a consistent way, such that:
(1) If the device's type is defined (eg. dev->type is not NULL)
and its pm pointer is not NULL, the callbacks from dev->type->pm
will be used.
(2) If dev->type is NULL or dev->type->pm is NULL, but the device's
class is defined (eg. dev->class is not NULL) and its pm pointer
is not NULL, the callbacks from dev->class->pm will be used.
(3) If dev->type is NULL or dev->type->pm is NULL and dev->class is
NULL or dev->class->pm is NULL, the callbacks from dev->bus->pm
will be used provided that both dev->bus and dev->bus->pm are
not NULL.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
Reasoning-sounds-sane-to: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
The platform bus type is often used to handle Systems-on-a-Chip (SoC)
where all devices are represented by objects of type struct
platform_device. In those cases the same "platform" device driver
may be used with multiple different system configurations, but the
actions needed to put the devices it handles into a low-power state
and back into the full-power state may depend on the design of the
given SoC. The driver, however, cannot possibly include all the
information necessary for the power management of its device on all
the systems it is used with. Moreover, the device hierarchy in its
current form also is not suitable for representing this kind of
information.
The patch below attempts to address this problem by introducing
objects of type struct dev_power_domain that can be used for
representing power domains within a SoC. Every struct
dev_power_domain object provides a sets of device power
management callbacks that can be used to perform what's needed for
device power management in addition to the operations carried out by
the device's driver and subsystem.
Namely, if a struct dev_power_domain object is pointed to by the
pwr_domain field in a struct device, the callbacks provided by its
ops member will be executed in addition to the corresponding
callbacks provided by the device's subsystem and driver during all
power transitions.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-and-acked-by: Kevin Hilman <khilman@ti.com>
The dpm_prepare() function increments the runtime PM reference
counters of all devices to prevent pm_runtime_suspend() from
executing subsystem-level callbacks. However, this was supposed to
guard against a specific race condition that cannot happen, because
the power management workqueue is freezable, so pm_runtime_suspend()
can only be called synchronously during system suspend and we can
rely on subsystems and device drivers to avoid doing that
unnecessarily.
Make dpm_prepare() drop the runtime PM reference to each device
after making sure that runtime resume is not pending for it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
After redefining CONFIG_PM to depend on (CONFIG_PM_SLEEP ||
CONFIG_PM_RUNTIME) the CONFIG_PM_OPS option is redundant and can be
replaced with CONFIG_PM.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Currently, wakeup sysfs attributes are created for all devices,
regardless of whether or not they are wakeup-capable. This is
excessive and complicates wakeup device identification from user
space (i.e. to identify wakeup-capable devices user space has to read
/sys/devices/.../power/wakeup for all devices and see if they are not
empty).
Fix this issue by avoiding to create wakeup sysfs files for devices
that cannot wake up the system from sleep states (i.e. whose
power.can_wakeup flags are unset during registration) and modify
device_set_wakeup_capable() so that it adds (or removes) the relevant
sysfs attributes if a device's wakeup capability status is changed.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
printk()s without a priority level default to KERN_WARNING. To reduce
noise at KERN_WARNING, this patch sets the priority level appriopriately
for unleveled printks()s. This should be useful to folks that look at
dmesg warnings closely.
Changed these messages to pr_info().
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Since pm_save_wakeup_count() has just been changed to clear
events_check_enabled unconditionally before checking if there are
any new wakeup events registered since the last read from
/sys/power/wakeup_count, the detection of wakeup events during
suspend may be disabled, after it's been enabled, by writing a
"wrong" value back to /sys/power/wakeup_count. For this reason,
it is not necessary to update events_check_enabled in
pm_get_wakeup_count() any more.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
According to Documentation/ABI/testing/sysfs-power, the
/sys/power/wakeup_count interface should only make the kernel react
to wakeup events during suspend if the last write to it has been
successful. However, if /sys/power/wakeup_count is written to two
times in a row, where the first write is successful and the second
is not, the kernel will still react to wakeup events during suspend
due to a bug in pm_save_wakeup_count().
Fix the bug by making pm_save_wakeup_count() clear
events_check_enabled unconditionally before checking if there are
any new wakeup events registered since the previous read from
/sys/power/wakeup_count.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The memory barrier in wakeup_source_deactivate() is supposed to
prevent the callers of pm_wakeup_pending() and pm_get_wakeup_count()
from seeing the new value of events_in_progress (0, in particular)
and the old value of event_count at the same time. However, if
wakeup_source_deactivate() is executed by CPU0 and, for instance,
pm_wakeup_pending() is executed by CPU1, where both processors can
reorder operations, the memory barrier in wakeup_source_deactivate()
doesn't affect CPU1 which can reorder reads. In that case CPU1 may
very well decide to fetch event_count before it's modified and
events_in_progress after it's been updated, so pm_wakeup_pending()
may fail to detect a wakeup event. This issue can be addressed by
using a single atomic variable to store both events_in_progress
and event_count, so that they can be updated together in a single
atomic operation.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1445) fixes a bug in the runtime PM core left over from
the addition of the no_callbacks flag. If this flag is set then it is
possible for rpm_suspend() to be called in_interrupt, so when
releasing spinlocks it's important not to re-enable interrupts.
To avoid an unnecessary save-and-restore of the interrupt flag, the
patch also inlines a pm_request_idle() call.
This fixes Bugzilla #27482.
(The offending code was added in 2.6.37, so it's not necessary to apply
this to any earlier stable kernels.)
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: tim blechmann <tim@klingt.org>
CC: <stable@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The __pm_generic_resume() function changes the given device's runtime
PM status to RPM_ACTIVE if its driver's callback returns 0, but it
only should do that if the rumtime PM is enabled for the device.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The registration of a new parentless device during system suspend
will not lead to any complications affecting the PM core (the device
will be effectively seen after the subsequent resume has completed),
so remove the code used for detection of such events.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The device power.status field is too complicated for its purpose
(storing the information about whether or not the device is in the
"active" state from the PM core's point of view), so replace it with
a bit field and modify all of its users accordingly.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Since a separate list of devices is used to link devices that have
completed each stage of suspend (or resume), it is not necessary to
check dev->power.status in the core device resume routines any more.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Instead of keeping all devices in the same list during system suspend
and resume, regardless of what suspend-resume callbacks have been
executed for them already, use separate lists of devices that have
had their ->prepare(), ->suspend() and ->suspend_noirq() callbacks
executed. This will allow us to simplify the core device suspend and
resume routines.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The compiler complains that calltime may be uninitialized in
pm_noirq_op(), so add extra initialization for that variable to
avoid the warning.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Before starting to suspend a device in __device_suspend() check if
there's a request to abort the power transition and return -EBUSY
in that case.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
To avoid confusion with the meaning and return value of
pm_check_wakeup_events() replace it with pm_wakeup_pending() that
will work the other way around (ie. return true when system-wide
power transition should be aborted).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Currently dpm_prepare() returns error code if it finds that a device
being suspended has a pending runtime resume request. However, it
should not do that if the checking for wakeup events is not enabled.
On the other hand, if the checking for wakeup events is enabled, it
can return error when a wakeup event is detected, regardless of its
source.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1431c) makes the synchronous runtime-PM interface
suitable for use in interrupt handlers. Subsystems can call the new
pm_runtime_irq_safe() function to tell the PM core that a device's
runtime_suspend and runtime_resume callbacks should be invoked with
interrupts disabled and the spinlock held. This permits the
pm_runtime_get_sync() and the new pm_runtime_put_sync_suspend()
routines to be called from within interrupt handlers.
When a device is declared irq-safe in this way, the PM core increments
the parent's usage count, so the parent will never be runtime
suspended. This prevents difficult situations in which an irq-safe
device can't resume because it is forced to wait for its non-irq-safe
parent.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Commit 05aa55dddb changed routines to
succeed if the driver handler is not defined. Comments were not updated.
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Conflicts:
MAINTAINERS
arch/arm/mach-omap2/pm24xx.c
drivers/scsi/bfa/bfa_fcpim.c
Needed to update to apply fixes for which the old branch was too
outdated.
Holding dpm_list_mtx across late suspend and early resume of devices
is problematic for the PCMCIA subsystem and doesn't allow device
objects to be removed by late suspend and early resume driver
callbacks. This appears to be overly restrictive, as drivers are
generally allowed to remove device objects in other phases of suspend
and resume. Therefore rework dpm_{suspend|resume}_noirq() so that
they don't have to hold dpm_list_mtx all the time.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
GCC version 4.5.1 gives the following warning:
drivers/base/power/runtime.c: In function ‘rpm_check_suspend_allowed’:
drivers/base/power/runtime.c:146:25: warning: comparison between ‘enum dpm_state’ and ‘enum rpm_status’
which seems to be a typo in that dev->power.runtime_status
should be compared instead of dev->power.status.
Signed-off-by: Kevin Winchester <kjwinchester@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
For device with no_callbacks flag set, its power lock and its parent's
power lock may be held nestedly in rpm_resume, so we should take
spin_lock_nested(lock, SINGLE_DEPTH_NESTING) to acquire parent power lock
to avoid lockdep warning.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
There may be wakeup sources that aren't associated with any devices
and their statistics information won't be available from sysfs. Also,
for debugging purposes it is convenient to have all of the wakeup
sources statistics available from one place. For these reasons,
introduce new file "wakeup_sources" in debugfs containing those
statistics.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
SoCs have a standard set of tuples consisting of frequency and
voltage pairs that the device will support per voltage domain. These
are called Operating Performance Points or OPPs. The actual
definitions of OPP varies over silicon versions. For a specific domain,
we can have a set of {frequency, voltage} pairs. As the kernel boots
and more information is available, a default set of these are activated
based on the precise nature of device. Further on operation, based on
conditions prevailing in the system (such as temperature), some OPP
availability may be temporarily controlled by the SoC frameworks.
To implement an OPP, some sort of power management support is necessary
hence this library depends on CONFIG_PM.
Contributions include:
Sanjeev Premi for the initial concept:
http://patchwork.kernel.org/patch/50998/
Kevin Hilman for converting original design to device-based.
Kevin Hilman and Paul Walmsey for cleaning up many of the function
abstractions, improvements and data structure handling.
Romit Dasgupta for using enums instead of opp pointers.
Thara Gopinath, Eduardo Valentin and Vishwanath BS for fixes and
cleanups.
Linus Walleij for recommending this layer be made generic for usage
in other architectures beyond OMAP and ARM.
Mark Brown, Andrew Morton, Rafael J. Wysocki, Paul E. McKenney for
valuable improvements.
Discussions and comments from:
http://marc.info/?l=linux-omap&m=126033945313269&w=2http://marc.info/?l=linux-omap&m=125482970102327&w=2http://marc.info/?t=125809247500002&r=1&w=2http://marc.info/?l=linux-omap&m=126025973426007&w=2http://marc.info/?t=128152609200064&r=1&w=2http://marc.info/?t=128468723000002&r=1&w=2
incorporated.
v1: http://marc.info/?t=128468723000002&r=1&w=2
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
If the device which fails to resume is part of a loadable kernel module
it won't be checked at startup against the magic number stored in the
RTC.
Add a read-only sysfs attribute /sys/power/pm_trace_dev_match which
contains a list of newline separated devices (usually just the one)
which currently match the last magic number. This allows the device
which is failing to resume to be found after the modules are loaded
again.
Signed-off-by: James Hogan <james@albanarts.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Lock the PM device list mutex using device_pm_lock() and
device_pm_unlock() around the list iteration in show_dev_hash().
show_dev_hash() was reverse iterating dpm_list without first locking the
mutex that the functions in drivers/base/power/main.c lock. I assume
this was unintentional since there is no comment suggesting why the lock
might not be necessary.
Signed-off-by: James Hogan <james@albanarts.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
If runtime suspend of a device fails returning -EAGAIN or -EBUSY,
which means that it's safe to try to suspend it again, the PM core
runs the runtime idle helper function for it. Unfortunately this may
lead to problems, for example for PCI devices whose drivers don't
implement the ->runtime_idle() callback, because in that case the
PCI bus type's ->runtime_idle() always calls pm_runtime_suspend()
for the given device. Then, if there's an automatic idle
notification after the driver's ->runtime_suspend() returning -EAGAIN
or -EBUSY, it will make the suspend happen again possibly causing a
busy loop to appear. To avoid that, remove the idle notification
after failing runtime suspend of a device altogether and let the
callers of pm_runtime_suspend() repeat the operation if need be.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Reduce code duplication in rpm_idle(), rpm_suspend() and rpm_resume()
by using local pointers to store callback addresses and moving some
duplicated code into a separate function.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
This patch (as1427) implements the "autosuspend" facility for runtime
PM. A few new fields are added to the dev_pm_info structure and
several new PM helper functions are defined, for telling the PM core
whether or not a device uses autosuspend, for setting the autosuspend
delay, and for marking periods of device activity.
Drivers that do not want to use autosuspend can continue using the
same helper functions as before; their behavior will not change. In
addition, drivers supporting autosuspend can also call the old helper
functions to get the old behavior.
The details are all explained in Documentation/power/runtime_pm.txt
and Documentation/ABI/testing/sysfs-devices-power.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Some devices, such as USB interfaces, cannot be power-managed
independently of their parents, i.e., they cannot be put in low power
while the parent remains at full power. This patch (as1425) creates a
new "no_callbacks" flag, which tells the PM core not to invoke the
runtime-PM callback routines for the such devices but instead to
assume that the callbacks always succeed. In addition, the
non-debugging runtime-PM sysfs attributes for the devices are removed,
since they are pretty much meaningless.
The advantage of this scheme comes not so much from avoiding the
callbacks themselves, but rather from the fact that without the need
for a process context in which to run the callbacks, more work can be
done in interrupt context.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1424) combines the various public entry points for the
runtime PM routines into three simple functions: one for idle, one for
suspend, and one for resume. A new bitflag specifies whether or not
to increment or decrement the usage_count field.
The new entry points are named __pm_runtime_idle,
__pm_runtime_suspend, and __pm_runtime_resume, to reflect that they
are trampolines. Simultaneously, the corresponding internal routines
are renamed to rpm_idle, rpm_suspend, and rpm_resume.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1423) merges the asynchronous routines
__pm_request_idle(), __pm_request_suspend(), and __pm_request_resume()
with their synchronous counterparts. The RPM_ASYNC bitflag argument
serves to indicate what sort of operation to perform.
In the course of performing this merger, it became apparent that the
various functions don't all behave consistenly with regard to error
reporting and cancellation of outstanding requests. A new routine,
rpm_check_suspend_allowed(), was written to centralize much of the
testing, and the other functions were revised to follow a simple
algorithm:
If the operation is disallowed because of the device's
settings or current state, return an error.
Cancel pending or scheduled requests of lower priority.
Schedule, queue, or perform the desired operation.
A few special cases and exceptions are noted in comments.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The "from_wq" argument in __pm_runtime_suspend() and
__pm_runtime_resume() supposedly indicates whether or not the function
was called by the PM workqueue thread, but in fact it isn't always
used this way. It really indicates whether or not the function should
return early if the requested operation is already in progress.
Along with this badly-named boolean argument, later patches in this
series will add several other boolean arguments to these functions and
others. Therefore this patch (as1422) begins the conversion process
by replacing from_wq with a bitflag argument. The same bitflags are
also used in __pm_runtime_get() and __pm_runtime_put(), where they
indicate whether or not the operation should be asynchronous.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1421) moves the PM runtime accounting subroutines up to
the beginning of runtime.c, taking them out of the middle of the
functions that do the actual work. No operational changes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
There is a potential issue with the asynchronous suspend code that
a device driver suspending asynchronously may not notice that it
should back off. There are two failing scenarions, (1) when the
driver is waiting for a driver suspending synchronously to complete
and that second driver returns error code, in which case async_error
won't be set and the waiting driver will continue suspending and (2)
after the driver has called device_pm_wait_for_dev() and the waited
for driver returns error code, in which case the caller of
device_pm_wait_for_dev() will not know that there was an error and
will continue suspending.
To fix this issue make __device_suspend() set async_error, so
async_suspend() doesn't need to set it any more, and make
device_pm_wait_for_dev() return async_error, so that its callers
can check whether or not they should continue suspending.
No more changes are necessary, since device_pm_wait_for_dev() is
not used by any drivers' suspend routines.
Reported-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Introduce struct wakeup_source for representing system wakeup sources
within the kernel and for collecting statistics related to them.
Make the recently introduced helper functions pm_wakeup_event(),
pm_stay_awake() and pm_relax() use struct wakeup_source objects
internally, so that wakeup statistics associated with wakeup devices
can be collected and reported in a consistent way (the definition of
pm_relax() is changed, which is harmless, because this function is
not called directly by anyone yet). Introduce new wakeup-related
sysfs device attributes in /sys/devices/.../power for reporting the
device wakeup statistics.
Change the global wakeup events counters event_count and
events_in_progress into atomic variables, so that it is not necessary
to acquire a global spinlock in pm_wakeup_event(), pm_stay_awake()
and pm_relax(), which should allow us to avoid lock contention in
these functions on SMP systems with many wakeup devices.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Seen on MIPS32, gcc 4.4.3, 2.6.36-rc4:
drivers/base/power/main.c: In function 'dpm_show_time':
drivers/base/power/main.c:415: warning: comparison of distinct pointer types lacks a cast
do_div() takes unsigned parameters:
uint32_t do_div(uint64_t *n, uint32_t base);
Using an unsigned variable for usecs64 should not cause any problems,
because calltime >= starttime .
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Allow drivers, that belong to subsystems which use the generic
runtime pm callbacks, not to define runtime pm suspend/resume handlers,
by implicitly assuming success in such cases.
This is needed to eliminate nop handlers that would otherwise be
necessary by drivers which enable runtime pm, but don't need
to do anything when their devices are runtime-suspended/resumed.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
During suspend, the power.completion is expected to be set when a
device has not yet started suspending. Set it on init to fix a
corner case where a device is resumed when its parent has never
suspended.
Consider three drivers, A, B, and C. The parent of A is C, and C
has async_suspend set. On boot, C->power.completion is initialized
to 0.
During the first suspend:
suspend_devices_and_enter(...)
dpm_resume(...)
device_suspend(A)
device_suspend(B) returns error, aborts suspend
dpm_resume_end(...)
dpm_resume(...)
device_resume(A)
dpm_wait(A->parent == C)
wait_for_completion(C->power.completion)
The wait_for_completion will never complete, because
complete_all(C->power.completion) will only be called from
device_suspend(C) or device_resume(C), neither of which is called
if suspend is aborted before C.
After a successful suspend->resume cycle, where B doesn't abort
suspend, C->power.completion is left in the completed state by the
call to device_resume(C), and the same call path will work if B
aborts suspend.
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
In order for PowerTOP to be able to report how well the new runtime PM is
working for the various drivers, the kernel needs to export some basic
statistics in sysfs.
This patch adds two sysfs files in the runtime PM domain that expose the
total time a device has been active, and the time a device has been
suspended.
With this PowerTOP can compute the activity percentage
Active %age = 100 * (delta active) / (delta active + delta suspended)
and present the information to the user.
I've written the PowerTOP code (slated for version 1.12) already, and the
output looks like this:
Runtime Device Power Management statistics
Active Device name
10.0% 06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller
[version 2: fix stat update bugs noticed by Alan Stern]
[version 3: rebase to -next and move the sysfs declaration]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1404b) makes the runtime_status sysfs attribute available
even in the absence of CONFIG_PM_ADVANCED_DEBUG, and it changes the
routine to display "unsupported" when runtime PM is disabled for a
device. Although not strictly 100% accurate, this will almost always
be correct.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Originally, pm_wakeup_event() uses struct delayed_work objects,
allocated with GFP_ATOMIC, to schedule the execution of pm_relax()
in future. However, as noted by Alan Stern, it is not necessary to
do that, because all pm_wakeup_event() calls can use one static timer
that will always be set to expire at the latest time passed to
pm_wakeup_event().
The modifications are based on the example code posted by Alan.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
One of the arguments during the suspend blockers discussion was that
the mainline kernel didn't contain any mechanisms making it possible
to avoid races between wakeup and system suspend.
Generally, there are two problems in that area. First, if a wakeup
event occurs exactly when /sys/power/state is being written to, it
may be delivered to user space right before the freezer kicks in, so
the user space consumer of the event may not be able to process it
before the system is suspended. Second, if a wakeup event occurs
after user space has been frozen, it is not generally guaranteed that
the ongoing transition of the system into a sleep state will be
aborted.
To address these issues introduce a new global sysfs attribute,
/sys/power/wakeup_count, associated with a running counter of wakeup
events and three helper functions, pm_stay_awake(), pm_relax(), and
pm_wakeup_event(), that may be used by kernel subsystems to control
the behavior of this attribute and to request the PM core to abort
system transitions into a sleep state already in progress.
The /sys/power/wakeup_count file may be read from or written to by
user space. Reads will always succeed (unless interrupted by a
signal) and return the current value of the wakeup events counter.
Writes, however, will only succeed if the written number is equal to
the current value of the wakeup events counter. If a write is
successful, it will cause the kernel to save the current value of the
wakeup events counter and to abort the subsequent system transition
into a sleep state if any wakeup events are reported after the write
has returned.
[The assumption is that before writing to /sys/power/state user space
will first read from /sys/power/wakeup_count. Next, user space
consumers of wakeup events will have a chance to acknowledge or
veto the upcoming system transition to a sleep state. Finally, if
the transition is allowed to proceed, /sys/power/wakeup_count will
be written to and if that succeeds, /sys/power/state will be written
to as well. Still, if any wakeup events are reported to the PM core
by kernel subsystems after that point, the transition will be
aborted.]
Additionally, put a wakeup events counter into struct dev_pm_info and
make these per-device wakeup event counters available via sysfs,
so that it's possible to check the activity of various wakeup event
sources within the kernel.
To illustrate how subsystems can use pm_wakeup_event(), make the
low-level PCI runtime PM wakeup-handling code use it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: markgross <markgross@thegnar.org>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Add a few sysfs files relating to runtime power management for
advanced debug purposes:
runtime_enabled: is runtime PM enabled for this device? States
are "enabled", "disabled", "forbidden" or a combination
of the latter two.
runtime_status: what state is the device in currently? E.g., it
reports "suspended" for runtime-suspended devices, and
"active" for active devices. NOTE: if runtime_enabled
returns "disabled", the value of this file may not
reflect its physical state.
runtime_usage: the runtime PM usage count of a device
runtime_active_kids: the runtime PM children usage count of a device, or
0 if the ignore_children flag is set.
Also, CONFIG_PM_SLEEP_ADVANCED_DEBUG is not defined in any Kconfig
file, so replace it with CONFIG_PM_ADVANCED_DEBUG.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1361) changes the runtime PM interface slightly; it
allows suspend requests to be scheduled while the runtime_suspend
method is running. If the method succeeds then the scheduled request
is cancelled, whereas if the method fails then an idle notification is
sent only if no request was scheduled.
Being able to schedule suspend requests from within a runtime_suspend
method is useful for drivers that need to test for idleness and
suspend the device all while holding a single spinlock, or for drivers
that want to check for idleness by polling.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The new-style dev_pm_ops provide callbacks for both IRQs enabled
and disabled. However, the _noirq variants were only called for
buses registered with a device, not for classes and types.
In order to properly use dev_pm_ops in class pcmcia_socket_class,
support _noirq actions also on classes and types.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
In the future, we are going to be changing the lock type for struct
device (once we get the lockdep infrastructure properly worked out) To
make that changeover easier, and to possibly burry the lock in a
different part of struct device, let's create some functions to lock and
unlock a device so that no out-of-core code needs to be changed in the
future.
This patch creates the device_lock/unlock/trylock() functions, and
converts all in-tree users to them.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Cc: Magnus Damm <damm@igel.co.jp>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Alex Chiang <achiang@hp.com>
Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrew Patterson <andrew.patterson@hp.com>
Cc: Yu Zhao <yu.zhao@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: CHENG Renquan <rqcheng@smu.edu.sg>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Frans Pop <elendil@planet.nl>
Cc: David Vrabel <david.vrabel@csr.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are subsystems whose power management callbacks only need to
invoke the callbacks provided by device drivers. Still, their system
sleep PM callbacks should play well with the runtime PM callbacks,
so that devices suspended at run time can be left in that state for
a system sleep transition.
Provide a set of generic PM callbacks for such subsystems and
define convenience macros for populating dev_pm_ops structures.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
There are some dependencies between devices (in particular, between
EHCI USB controllers and their OHCI/UHCI siblings) which are not
reflected by the structure of the device tree. With synchronous
suspend and resume these dependencies are taken into accout
automatically, because the devices in question are always registered
in the right order, but to meet these constraints with asynchronous
suspend and resume the drivers of these devices will need to use
dpm_wait() in their suspend/resume routines, so introduce a helper
function allowing them to do that.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
It has been shown by testing that total device resume time can be
reduced significantly (by as much as 50% or more) if the async
threads executing some devices' resume routines are all started
before the main resume thread starts to handle the "synchronous"
devices.
This is a consequence of the fact that the slowest devices tend to be
located at the end of dpm_list, so their resume routines are started
very late. Consequently, they have to wait for all the preceding
"synchronous" devices before their resume routines can be started
by the main resume thread, even if they are "asynchronous". By
starting their async threads upfront we effectively move those
devices towards the beginning of dpm_list, without breaking their
ordering with respect to their parents and children. As a result,
their resume routines are started much earlier and we are able to
save much more device resume time this way.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Add configuration switch CONFIG_PM_ADVANCED_DEBUG for compiling in
extra PM debugging/testing code allowing one to access some
PM-related attributes of devices from the user space via sysfs.
If CONFIG_PM_ADVANCED_DEBUG is set, add sysfs attribute power/async
for every device allowing the user space to access the device's
power.async_suspend flag and modify it, if desired.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Add sysfs attribute /sys/power/pm_async allowing the user space to
disable/enable asynchronous suspend/resume of devices.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Theoretically, the total time of system sleep transitions (suspend
to RAM, hibernation) can be reduced by running suspend and resume
callbacks of device drivers in parallel with each other. However,
there are dependencies between devices such that we're not allowed
to suspend the parent of a device before suspending the device
itself. Analogously, we're not allowed to resume a device before
resuming its parent.
The most straightforward way to take these dependencies into accout
is to start the async threads used for suspending and resuming
devices at the core level, so that async_schedule() is called for
each suspend and resume callback supposed to be executed
asynchronously.
For this purpose, introduce a new device flag, power.async_suspend,
used to mark the devices whose suspend and resume callbacks are to be
executed asynchronously (ie. in parallel with the main suspend/resume
thread and possibly in parallel with each other) and helper function
device_enable_async_suspend() allowing one to set power.async_suspend
for given device (power.async_suspend is unset by default for all
devices). For each device with the power.async_suspend flag set the
PM core will use async_schedule() to execute its suspend and resume
callbacks.
The async threads started for different devices as a result of
calling async_schedule() are synchronized with each other and with
the main suspend/resume thread with the help of completions, in the
following way:
(1) There is a completion, power.completion, for each device object.
(2) Each device's completion is reset before calling async_schedule()
for the device or, in the case of devices with the
power.async_suspend flags unset, before executing the device's
suspend and resume callbacks.
(3) During suspend, right before running the bus type, device type
and device class suspend callbacks for the device, the PM core
waits for the completions of all the device's children to be
completed.
(4) During resume, right before running the bus type, device type and
device class resume callbacks for the device, the PM core waits
for the completion of the device's parent to be completed.
(5) The PM core completes power.completion for each device right
after the bus type, device type and device class suspend (or
resume) callbacks executed for the device have returned.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Add new device sysfs attribute, power/control, allowing the user
space to block the run-time power management of the devices. If this
attribute is set to "on", the driver of the device won't be able to power
manage it at run time (without breaking the rules) and the device will
always be in the full power state (except when the entire system goes
into a sleep state).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Warning(drivers/base/power/main.c:453): No description found for parameter 'dev'
Warning(drivers/base/power/main.c:453): No description found for parameter 'cb'
Warning(drivers/base/power/main.c:719): No description found for parameter 'dev'
Warning(drivers/base/power/main.c:719): No description found for parameter 'state'
Warning(drivers/base/power/main.c:719): No description found for parameter 'cb'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The power management of some devices is handled through device types
and device classes rather than through bus types. Since these
devices may also benefit from using the run-time power management
core, extend it so that the device type and device class run-time PM
callbacks can be taken into consideration by it if the bus type
callback is not defined.
Update the run-time PM core documentation to reflect this change.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1317) fixes a bug in the PM core. When a device is
resumed following a system sleep, the core decrements the device's
runtime PM usage counter but doesn't issue an idle notification if the
counter reaches 0. This could prevent an otherwise unused device from
being runtime-suspended again after the system sleep.
The fix is to call pm_runtime_put_sync() instead of
pm_runtime_put_noidle().
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Commit f251177486
(PM: Add initcall_debug style timing for suspend/resume) introduced
basic timing instrumentation, needed for a scritps/bootgraph.pl
equivalent or humans, but it missed the fact that bus types and
device classes which haven't been switched to using struct dev_pm_ops
objects yet need special handling. As a result, the suspend/resume
timing information is only available for devices whose bus types or
device classes use struct dev_pm_ops objects, so the majority of
devices is not covered.
Fix this by adding basic suspend/resume timing instrumentation for
devices whose bus types and device classes still don't use struct
dev_pm_ops objects for power management. To reduce code duplication
move the timing code to helper functions.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
In device_resume_noirq() there is the 'End' label and the associated
goto statement that aren't strictly necessary, so rework the code to
get rid of them. Also modify device_suspend_noirq() so that it looks
completely analogous to device_resume_noirq().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
In order to diagnose overall suspend/resume times, we need
basic instrumentation to break down the total time into per
device timing, similar to initcall_debug.
This patch adds the basic timing instrumentation, needed
for a scritps/bootgraph.pl equivalent or humans.
The bootgraph.pl program is still a work in progress, but
is far enough along to know that this patch is sufficient.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1308c) fixes __pm_runtime_get(). Currently the routine
will resume a device if the prior usage count was 0. But this isn't
right; thanks to pm_runtime_get_noresume() the usage count can be
positive even while the device is suspended.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The runtime PM core code assumes that dev->power.timer_expires is
nonzero when the timer is scheduled, but it may become zero
incidentally in pm_schedule_suspend(). Prevent this from happening
by bumping dev->power.timer_expires up to 1 if it's 0 before calling
mod_timer().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
This patch (as1307) adds a small optimization to
__pm_request_resume(). If the device is currently being suspended,
there's no need to queue a work routine to resume it. Setting the
deferred_resume flag will suffice. (There's also a minor improvement
to the function's code layout: An unnecessary "else" is removed.)
Also, the patch clarifies the usage of the deferred_resume flag. It
is meaningful only while a suspend is in progress, so it should be
cleared just before a suspend starts, not just after one ends.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Lockdep complains about taking the parent lock in
__pm_runtime_set_status(), so mark it as nested.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@kernel.org
This patch (as1305) fixes a bug in the irq-enable settings and removes
some related overhead in the runtime PM code.
In __pm_runtime_resume(), within the scope of the original
spin_lock_irq(), we know that irqs are disabled. There's no
reason to go through a pair of enable/disable cycles when
acquiring and releasing the parent's lock.
In __pm_runtime_set_status(), irqs are already disabled when
the parent's lock is acquired, and they must remain disabled
when it is released.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Fixes the point where we need to complete the power transition when
device suspend fails, so that we don't print warnings about devices
added to the device hierarchy after a failing suspend.
[rjw: Modified changelog.]
Signed-off-by: Romit Dasgupta <romit@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
transition_started should be set once the preparation of devices for
a PM has started, reset before starting to resume devices. When
resuming devices, kernel calls dpm_resume_noirq then
dpm_resume_end(dpm_resume). Thus we should reset transition_started
at dpm_resume_noirq.
This patch fixes ACPI warning when resuming from suspend/hibernate:
ACPI: \_SB_.PCI0.IDE1.PRI1.MAS1 - docking
------------[ cut here ]------------
WARNING: at drivers/base/power/main.c:87 device_pm_add+0x8b/0xcc()
Hardware name: OptiPlex 760
Device: acpi
Parentless device registered during a PM transaction
[rjw: Fixed up the changelog.]
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The kerneldoc comments in drivers/base/power/main.c are generally
outdated and some of them don't describe the functions very
accurately. Update them and standardize the format to use spaces
instead of tabs.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Introduce a core framework for run-time power management of I/O
devices. Add device run-time PM fields to 'struct dev_pm_info'
and device run-time PM callbacks to 'struct dev_pm_ops'. Introduce
a run-time PM workqueue and define some device run-time PM helper
functions at the core level. Document all these things.
Special thanks to Alan Stern for his help with the design and
multiple detailed reviews of the pereceding versions of this patch
and to Magnus Damm for testing feedback.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@igel.co.jp>
They are not supposed to be modified by drivers, so make them const.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
When the last device in the dpm list is unregistered directly after its
prepare() callback returned with -EAGAIN, the return code is passed to
the calling function, resulting in a suspend failure. Prevent this by
clearing the return code after -EAGAIN.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch removes the legacy callbacks ->suspend() and
->resume() from struct device_type. These callbacks seem
unused, and new code should instead make use of struct
dev_pm_ops.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Remove the ->suspend_late() and ->resume_early() callbacks
from struct bus_type V2. These callbacks are legacy stuff
at this point and since there seem to be no in-tree users
we may as well remove them. New users should use dev_pm_ops.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch (as1241) renames a bunch of functions in the PM core.
Rather than go through a boring list of name changes, suffice it to
say that in the end we have a bunch of pairs of functions:
device_resume_noirq dpm_resume_noirq
device_resume dpm_resume
device_complete dpm_complete
device_suspend_noirq dpm_suspend_noirq
device_suspend dpm_suspend
device_prepare dpm_prepare
in which device_X does the X operation on a single device and dpm_X
invokes device_X for all devices in the dpm_list.
In addition, the old dpm_power_up and device_resume_noirq have been
combined into a single function (dpm_resume_noirq).
Lastly, dpm_suspend_start and dpm_resume_end are the renamed versions
of the former top-level device_suspend and device_resume routines.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Rename the functions performing "_noirq" dev_pm_ops
operations from device_power_down() and device_power_up()
to device_suspend_noirq() and device_resume_noirq().
The new function names are chosen to show that the functions
are responsible for calling the _noirq() versions to finalize
the suspend/resume operation. The current function names do
not perform power down/up anymore so the names may be misleading.
Global function renames:
- device_power_down() -> device_suspend_noirq()
- device_power_up() -> device_resume_noirq()
Static function renames:
- suspend_device_noirq() -> __device_suspend_noirq()
- resume_device_noirq() -> __device_resume_noirq()
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Len Brown <lenb@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Rafael J. Wysocki