linux/kernel/power/Kconfig, branch v3.16

PM / OPP: Make OPP invisible to users in Kconfig

2014-05-19T21:03:31Z

The OPP code is an in kernel library selected by its users, there is no no architecture code required to implement it and enabling it without a user just increases the kernel size. Since the users select rather than depend on it just remove the ability to directly set the option from Kconfig. Signed-off-by: Mark Brown Acked-by: Nishanth Menon Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

PM / Sleep: Detect device suspend/resume lockup and log event

2013-10-18T11:33:08Z

Rather than hard-lock the kernel, dump the suspend/resume thread stack and panic() to capture a message in pstore when a driver takes too long to suspend/resume. Default suspend/resume watchdog timeout is set to 12 seconds to be longer than the usbhid 10 second timeout, but could be changed at compile time. Exclude from the watchdog the time spent waiting for children that are resumed asynchronously and time every device, whether or not they resumed synchronously. This patch is targeted for mobile devices where a suspend/resume lockup could cause a system reboot. Information about failing device can be retrieved in subsequent boot session by mounting pstore and inspecting the log. Laptops with EFI-enabled pstore could also benefit from this feature. The hardware watchdog timer is likely suspended during this time and couldn't be relied upon. The soft-lockup detector would eventually tell that tasks are not scheduled, but would provide little context as to why. The patch hence uses system timer and assumes it is still active while the devices are suspended/resumed. This feature can be enabled/disabled during kernel configuration. This change is based on earlier work by San Mehat. Signed-off-by: Benoit Goby Signed-off-by: Zoran Markovic Acked-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

Merge branch 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

2013-07-03T02:53:30Z

Pull workqueue changes from Tejun Heo: "Surprisingly, Lai and I didn't break too many things implementing custom pools and stuff last time around and there aren't any follow-up changes necessary at this point. The only change in this pull request is Viresh's patches to make some per-cpu workqueues to behave as unbound workqueues dependent on a boot param whose default can be configured via a config option. This leads to higher processing overhead / lower bandwidth as more work items are bounced across CPUs; however, it can lead to noticeable powersave in certain configurations - ~10% w/ idlish constant workload on a big.LITTLE configuration according to Viresh. This is because per-cpu workqueues interfere with how the scheduler perceives whether or not each CPU is idle by forcing pinned tasks on them, which makes the scheduler's power-aware scheduling decisions less effective. Its effectiveness is likely less pronounced on homogenous configurations and this type of optimization can probably be made automatic; however, the changes are pretty minimal and the affected workqueues are clearly marked, so it's an easy gain for some configurations for the time being with pretty unintrusive changes." * 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: fbcon: queue work on power efficient wq block: queue work on power efficient wq PHYLIB: queue work on system_power_efficient_wq workqueue: Add system wide power_efficient workqueues workqueues: Introduce new flag WQ_POWER_EFFICIENT for power oriented workqueues

Finally eradicate CONFIG_HOTPLUG

2013-06-03T21:20:18Z

Ever since commit 45f035ab9b8f ("CONFIG_HOTPLUG should be always on"), it has been basically impossible to build a kernel with CONFIG_HOTPLUG turned off. Remove all the remaining references to it. Cc: Russell King Cc: Doug Thompson Cc: Bjorn Helgaas Cc: Steven Whitehouse Cc: Arnd Bergmann Cc: Pavel Machek Cc: "Rafael J. Wysocki" Cc: Andrew Morton Signed-off-by: Stephen Rothwell Acked-by: Mauro Carvalho Chehab Acked-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman

workqueues: Introduce new flag WQ_POWER_EFFICIENT for power oriented workqueues

2013-05-14T17:50:06Z

Workqueues can be performance or power-oriented. Currently, most workqueues are bound to the CPU they were created on. This gives good performance (due to cache effects) at the cost of potentially waking up otherwise idle cores (Idle from scheduler's perspective. Which may or may not be physically idle) just to process some work. To save power, we can allow the work to be rescheduled on a core that is already awake. Workqueues created with the WQ_UNBOUND flag will allow some power savings. However, we don't change the default behaviour of the system. To enable power-saving behaviour, a new config option CONFIG_WQ_POWER_EFFICIENT needs to be turned on. This option can also be overridden by the workqueue.power_efficient boot parameter. tj: Updated config description and comments. Renamed CONFIG_WQ_POWER_EFFICIENT to CONFIG_WQ_POWER_EFFICIENT_DEFAULT. Signed-off-by: Viresh Kumar Reviewed-by: Amit Kucheria Signed-off-by: Tejun Heo

PM / Domains: Add power off/on function for system core suspend stage

2012-09-03T23:36:01Z

Introduce function pm_genpd_syscore_switch() and two wrappers around it, pm_genpd_syscore_poweroff() and pm_genpd_syscore_poweron(), allowing the callers to let the generic PM domains framework know that the given device is not necessary any more and its PM domain can be turned off (the former) or that the given device will be required immediately, so its PM domain has to be turned on (the latter) during the system core (syscore) stage of system suspend (or hibernation) and resume. These functions will be used for handling devices registered as clock sources and clock event devices that belong to PM domains. Signed-off-by: Rafael J. Wysocki

PM / Sleep: Separate printing suspend times from initcall_debug

2012-07-01T11:31:23Z

Change the behavior of the newly introduced /sys/power/pm_print_times attribute so that its initial value depends on initcall_debug, but setting it to 0 will cause device suspend/resume times not to be printed, even if initcall_debug has been set. This way, the people who use initcall_debug for reasons other than PM debugging will be able to switch the suspend/resume times printing off, if need be. Signed-off-by: Rafael J. Wysocki Reviewed-by: Srivatsa S. Bhat Acked-by: Greg Kroah-Hartman

PM / Sleep: User space wakeup sources garbage collector Kconfig option

2012-05-11T19:11:16Z

Make it possible to configure out the user space wakeup sources garbage collector for debugging and default Android builds. Signed-off-by: Rafael J. Wysocki Acked-by: Arve Hjønnevåg

PM / Sleep: Make the limit of user space wakeup sources configurable

2012-05-11T19:11:02Z

Make it possible to configure out the check against the limit of user space wakeup sources for debugging and default Android builds. Signed-off-by: Rafael J. Wysocki Acked-by: Arve Hjønnevåg

PM / Sleep: Add user space interface for manipulating wakeup sources, v3

2012-05-01T19:26:05Z

Android allows user space to manipulate wakelocks using two sysfs file located in /sys/power/, wake_lock and wake_unlock. Writing a wakelock name and optionally a timeout to the wake_lock file causes the wakelock whose name was written to be acquired (it is created before is necessary), optionally with the given timeout. Writing the name of a wakelock to wake_unlock causes that wakelock to be released. Implement an analogous interface for user space using wakeup sources. Add the /sys/power/wake_lock and /sys/power/wake_unlock files allowing user space to create, activate and deactivate wakeup sources, such that writing a name and optionally a timeout to wake_lock causes the wakeup source of that name to be activated, optionally with the given timeout. If that wakeup source doesn't exist, it will be created and then activated. Writing a name to wake_unlock causes the wakeup source of that name, if there is one, to be deactivated. Wakeup sources created with the help of wake_lock that haven't been used for more than 5 minutes are garbage collected and destroyed. Moreover, there can be only WL_NUMBER_LIMIT wakeup sources created with the help of wake_lock present at a time. The data type used to track wakeup sources created by user space is called "struct wakelock" to indicate the origins of this feature. This version of the patch includes an rbtree manipulation fix from John Stultz. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Reviewed-by: NeilBrown