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>
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>
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>
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>
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 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>
* Introduce function acpi_pm_device_sleep_wake() for enabling and
disabling the system wake-up capability of devices that are power
manageable by ACPI.
* Introduce function acpi_bus_can_wakeup() allowing other (dependent)
subsystems to check if ACPI is able to enable the system wake-up
capability of given device.
* Introduce callback .sleep_wake() in struct pci_platform_pm_ops and
for the ACPI PCI 'driver' make it use acpi_pm_device_sleep_wake().
* Introduce callback .can_wakeup() in struct pci_platform_pm_ops and
for the ACPI 'driver' make it use acpi_bus_can_wakeup().
* Move the PME# handlig code out of pci_enable_wake() and split it
into two functions, pci_pme_capable() and pci_pme_active(),
allowing the caller to check if given device is capable of
generating PME# from given power state and to enable/disable the
device's PME# functionality, respectively.
* Modify pci_enable_wake() to use the new ACPI callbacks and the new
PME#-related functions.
* Drop the generic .platform_enable_wakeup() callback that is not
used any more.
* Introduce device_set_wakeup_capable() that will set the
power.can_wakeup flag of given device.
* Rework PCI device PM initialization so that, if given device is
capable of generating wake-up events, either natively through the
PME# mechanism, or with the help of the platform, its
power.can_wakeup flag is set and its power.should_wakeup flag is
unset as appropriate.
* Make ACPI set the power.can_wakeup flag for devices found to be
wake-up capable by it.
* Make the ACPI wake-up code enable/disable GPEs for devices that
have the wakeup.flags.prepared flag set (which means that their
wake-up power has been enabled).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The various wakeup flags and their accessor macros in struct
dev_pm_info should be available whenever CONFIG_PM is enabled, not
just when CONFIG_PM_SLEEP is on. Otherwise remote wakeup won't always
be configurable for runtime power management. This patch (as1056b)
fixes the oversight.
David Brownell adds:
More accurately, fixes the "regression" ... as noted sometime
last summer, after 296699de6b
introduced CONFIG_SUSPEND. But that didn't make the regression
list for that kernel, ergo the delay in fixing it.
[rjw: rebased]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add a new PM_SYSFS_DEPRECATED config option to control whether or
not the /sys/devices/.../power/state files are provided. This will
make it easier to get rid of that mechanism when the time comes,
and to verify that userspace tools work right without it.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Updates to match current code:
- Make writes to the /sys/devices/.../power/state files fail cleanly
if the device requires the irqs-off call variants.
- Fix comments describing the /sys/devices/.../power/state file writes
to match the code; the last several releases have invalidated the
previous text.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix more include file problems that surfaced since I submitted the previous
fix-missing-includes.patch. This should now allow not to include sched.h
from module.h, which is done by a followup patch.
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is a refresh of an earlier patch to add "wakeup" support to the
PM core model. This provides per-device bus-neutral control of the
use of wakeup events.
* "struct device_pm_info" has two bits that are initialized as
part of setting up the enclosing struct device:
- "can_wakeup", reflecting hardware capabilities
- "may_wakeup", the policy setting (when CONFIG_PM)
* There's a writeable sysfs "wakeup" file, with one of two values:
- "enabled", when the policy is to allow wakeup
- "disabled", when the policy is not to allow it
- "" if the device can't currently issue wakeups
By default, wakeup is enabled on all devices that support it. If its
driver doesn't support it ... treat it as a bug. :)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds type-checking to pm_message_t, so that people can't confuse it
with int or u32. It also allows us to fix "disk yoyo" during suspend (disk
spinning down/up/down).
[We've tried that before; since that cpufreq problems were fixed and I've
tried make allyes config and fixed resulting damage.]
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Alexander Nyberg <alexn@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Alan Stern