user/sven/linux.git/include/linux/suspend.h, branch v4.2.4

PM / sleep: Re-implement suspend-to-idle handling

2015-02-13T22:49:36Z

In preparation for adding support for quiescing timers in the final stage of suspend-to-idle transitions, rework the freeze_enter() function making the system wait on a wakeup event, the freeze_wake() function terminating the suspend-to-idle loop and the mechanism by which deep idle states are entered during suspend-to-idle. First of all, introduce a simple state machine for suspend-to-idle and make the code in question use it. Second, prevent freeze_enter() from losing wakeup events due to race conditions and ensure that the number of online CPUs won't change while it is being executed. In addition to that, make it force all of the CPUs re-enter the idle loop in case they are in idle states already (so they can enter deeper idle states if possible). Next, drop cpuidle_use_deepest_state() and replace use_deepest_state checks in cpuidle_select() and cpuidle_reflect() with a single suspend-to-idle state check in cpuidle_idle_call(). Finally, introduce cpuidle_enter_freeze() that will simply find the deepest idle state available to the given CPU and enter it using cpuidle_enter(). Signed-off-by: Rafael J. Wysocki Acked-by: Peter Zijlstra (Intel)

ACPI / sleep: Rework the handling of ACPI GPE wakeup from suspend-to-idle

2014-09-30T19:06:07Z

The ACPI GPE wakeup from suspend-to-idle is currently based on using the IRQF_NO_SUSPEND flag for the ACPI SCI, but that is problematic for a couple of reasons. First, in principle the ACPI SCI may be shared and IRQF_NO_SUSPEND does not really work well with shared interrupts. Second, it may require the ACPI subsystem to special-case the handling of device notifications depending on whether or not they are received during suspend-to-idle in some places which would lead to fragile code. Finally, it's better the handle ACPI wakeup interrupts consistently with wakeup interrupts from other sources. For this reason, remove the IRQF_NO_SUSPEND flag from the ACPI SCI and use enable_irq_wake()/disable_irq_wake() with it instead, which requires two additional platform hooks to be added to struct platform_freeze_ops. Signed-off-by: Rafael J. Wysocki

PM / sleep: Mechanism for aborting system suspends unconditionally

2014-09-01T11:47:49Z

It sometimes may be necessary to abort a system suspend in progress or wake up the system from suspend-to-idle even if the pm_wakeup_event()/pm_stay_awake() mechanism is not enabled. For this purpose, introduce a new global variable pm_abort_suspend and make pm_wakeup_pending() check its value. Also add routines for manipulating that variable. Signed-off-by: Rafael J. Wysocki

PM / hibernate: introduce "nohibernate" boot parameter

2014-06-16T21:29:39Z

To support using kernel features that are not compatible with hibernation, this creates the "nohibernate" kernel boot parameter to disable both hibernation and resume. This allows hibernation support to be a boot-time choice instead of only a compile-time choice. Signed-off-by: Kees Cook Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki

Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm into next

2014-06-05T22:57:04Z

Pull ARM updates from Russell King: - Major clean-up of the L2 cache support code. The existing mess was becoming rather unmaintainable through all the additions that others have done over time. This turns it into a much nicer structure, and implements a few performance improvements as well. - Clean up some of the CP15 control register tweaks for alignment support, moving some code and data into alignment.c - DMA properties for ARM, from Santosh and reviewed by DT people. This adds DT properties to specify bus translations we can't discover automatically, and to indicate whether devices are coherent. - Hibernation support for ARM - Make ftrace work with read-only text in modules - add suspend support for PJ4B CPUs - rework interrupt masking for undefined instruction handling, which allows us to enable interrupts earlier in the handling of these exceptions. - support for big endian page tables - fix stacktrace support to exclude stacktrace functions from the trace, and add save_stack_trace_regs() implementation so that kprobes can record stack traces. - Add support for the Cortex-A17 CPU. - Remove last vestiges of ARM710 support. - Removal of ARM "meminfo" structure, finally converting us solely to memblock to handle the early memory initialisation. * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (142 commits) ARM: ensure C page table setup code follows assembly code (part II) ARM: ensure C page table setup code follows assembly code ARM: consolidate last remaining open-coded alignment trap enable ARM: remove global cr_no_alignment ARM: remove CPU_CP15 conditional from alignment.c ARM: remove unused adjust_cr() function ARM: move "noalign" command line option to alignment.c ARM: provide common method to clear bits in CPU control register ARM: 8025/1: Get rid of meminfo ARM: 8060/1: mm: allow sub-architectures to override PCI I/O memory type ARM: 8066/1: correction for ARM patch 8031/2 ARM: 8049/1: ftrace/add save_stack_trace_regs() implementation ARM: 8065/1: remove last use of CONFIG_CPU_ARM710 ARM: 8062/1: Modify ldrt fixup handler to re-execute the userspace instruction ARM: 8047/1: rwsem: use asm-generic rwsem implementation ARM: l2c: trial at enabling some Cortex-A9 optimisations ARM: l2c: add warnings for stuff modifying aux_ctrl register values ARM: l2c: print a warning with L2C-310 caches if the cache size is modified ARM: l2c: remove old .set_debug method ARM: l2c: kill L2X0_AUX_CTRL_MASK before anyone else makes use of this ...

ACPI / PM: Hold ACPI scan lock over the "freeze" sleep state

2014-05-16T10:18:27Z

The "freeze" sleep state suffers from the same issue that was addressed by commit ad07277e82de (ACPI / PM: Hold acpi_scan_lock over system PM transitions) for ACPI sleep states, that is, things break if ->remove() is called for devices whose system resume callbacks haven't been executed yet. It also can be addressed in the same way, by holding the ACPI scan lock over the "freeze" sleep state and PM transitions to and from that state, but ->begin() and ->end() platform operations for the "freeze" sleep state are needed for this purpose. This change has been tested on Acer Aspire S5 with Thunderbolt. Signed-off-by: Rafael J. Wysocki

ARM: 8011/1: ARM hibernation / suspend-to-disk

2014-04-23T00:24:14Z

Enable hibernation for ARM architectures and provide ARM architecture specific calls used during hibernation. The swsusp hibernation framework depends on the platform first having functional suspend/resume. Then, in order to enable hibernation on a given platform, a platform_hibernation_ops structure may need to be registered with the system in order to save/restore any SoC-specific / cpu specific state needing (re)init over a suspend-to-disk/resume-from-disk cycle. For example: - "secure" SoCs that have different sets of control registers and/or different CR reg access patterns. - SoCs with L2 caches as the activation sequence there is SoC-dependent; a full off-on cycle for L2 is not done by the hibernation support code. - SoCs requiring steps on wakeup _before_ the "generic" parts done by cpu_suspend / cpu_resume can work correctly. - SoCs having persistent state which is maintained during suspend and resume, but will be lost during the power off cycle after suspend-to-disk. This is a rebase/rework of Frank Hofmann's v5 hibernation patchset. Acked-by: Russ Dill Cc: "Rafael J. Wysocki" Signed-off-by: Sebastian Capella Acked-by: Pavel Machek Reviewed-by: Lorenzo Pieralisi [fixed duplicate virt_to_pfn() definition --rmk] Signed-off-by: Russell King

PM / Sleep: Print last wakeup source on failed wakeup_count write

2013-06-20T22:35:12Z

Commit a938da06 introduced a useful little log message to tell users/debuggers which wakeup source aborted a suspend. However, this message is only printed if the abort happens during the in-kernel suspend path (after writing /sys/power/state). The full specification of the /sys/power/wakeup_count facility allows user-space power managers to double-check if wakeups have already happened before it actually tries to suspend (e.g. while it was running user-space pre-suspend hooks), by writing the last known wakeup_count value to /sys/power/wakeup_count. This patch changes the sysfs handler for that node to also print said log message if that write fails, so that we can figure out the offending wakeup source for both kinds of suspend aborts. Signed-off-by: Julius Werner Signed-off-by: Rafael J. Wysocki

PM: Introduce suspend state PM_SUSPEND_FREEZE

2013-02-09T21:30:44Z

PM_SUSPEND_FREEZE state is a general state that does not need any platform specific support, it equals frozen processes + suspended devices + idle processors. Compared with PM_SUSPEND_MEMORY, PM_SUSPEND_FREEZE saves less power because the system is still in a running state. PM_SUSPEND_FREEZE has less resume latency because it does not touch BIOS, and the processors are in idle state. Compared with RTPM/idle, PM_SUSPEND_FREEZE saves more power as 1. the processor has longer sleep time because processes are frozen. The deeper c-state the processor supports, more power saving we can get. 2. PM_SUSPEND_FREEZE uses system suspend code path, thus we can get more power saving from the devices that does not have good RTPM support. This state is useful for 1) platforms that do not have STR, or have a broken STR. 2) platforms that have an extremely low power idle state, which can be used to replace STR. The following describes how PM_SUSPEND_FREEZE state works. 1. echo freeze > /sys/power/state 2. the processes are frozen. 3. all the devices are suspended. 4. all the processors are blocked by a wait queue 5. all the processors idles and enters (Deep) c-state. 6. an interrupt fires. 7. a processor is woken up and handles the irq. 8. if it is a general event, a) the irq handler runs and quites. b) goto step 4. 9. if it is a real wake event, say, power button pressing, keyboard touch, mouse moving, a) the irq handler runs and activate the wakeup source b) wakeup_source_activate() notifies the wait queue. c) system starts resuming from PM_SUSPEND_FREEZE 10. all the devices are resumed. 11. all the processes are unfrozen. 12. system is back to working. Known Issue: The wakeup of this new PM_SUSPEND_FREEZE state may behave differently from the previous suspend state. Take ACPI platform for example, there are some GPEs that only enabled when the system is in sleep state, to wake the system backk from S3/S4. But we are not touching these GPEs during transition to PM_SUSPEND_FREEZE. This means we may lose some wake event. But on the other hand, as we do not disable all the Interrupts during PM_SUSPEND_FREEZE, we may get some extra "wakeup" Interrupts, that are not available for S3/S4. The patches has been tested on an old Sony laptop, and here are the results: Average Power: 1. RPTM/idle for half an hour: 14.8W, 12.6W, 14.1W, 12.5W, 14.4W, 13.2W, 12.9W 2. Freeze for half an hour: 11W, 10.4W, 9.4W, 11.3W 10.5W 3. RTPM/idle for three hours: 11.6W 4. Freeze for three hours: 10W 5. Suspend to Memory: 0.5~0.9W Average Resume Latency: 1. RTPM/idle with a black screen: (From pressing keyboard to screen back) Less than 0.2s 2. Freeze: (From pressing power button to screen back) 2.50s 3. Suspend to Memory: (From pressing power button to screen back) 4.33s >From the results, we can see that all the platforms should benefit from this patch, even if it does not have Low Power S0. Signed-off-by: Zhang Rui 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