24 Oct, 2016
1 commit
-
Commit 4bcc595ccd80 (printk: reinstate KERN_CONT for printing
continuation lines) exposed a missing KERN_CONT from one of the
messages shown on entering suspend. With v4.9-rc1, the 'done.' shown
after syncing the filesystems no longer appears as a continuation but
a new message with its own timestamp.[ 9.259566] PM: Syncing filesystems ... [ 9.264119] done.
Fix this by adding the KERN_CONT log level for the 'done.' part of the
message seen after syncing filesystems. While we are at it, convert
these suspend printks to pr_info and pr_cont, respectively.Signed-off-by: Jon Hunter
Signed-off-by: Rafael J. Wysocki
13 Sep, 2016
1 commit
-
Suspend-to-idle (aka the "freeze" sleep state) is a system sleep state
in which all of the processors enter deepest possible idle state and
wait for interrupts right after suspending all the devices.There is no hard requirement for a platform to support and register
platform specific suspend_ops to enter suspend-to-idle/freeze state.
Only deeper system sleep states like PM_SUSPEND_STANDBY and
PM_SUSPEND_MEM rely on such low level support/implementation.suspend-to-idle can be entered as along as all the devices can be
suspended. This patch enables the support for suspend-to-idle even on
systems that don't have any low level support for deeper system sleep
states and/or don't register any platform specific suspend_ops.Signed-off-by: Sudeep Holla
Tested-by: Andy Gross
Signed-off-by: Rafael J. Wysocki
28 Jun, 2016
1 commit
-
This makes pm notifier PREPARE/POST symmetrical: if PREPARE
fails, we will only undo what ever happened on PREPARE.It fixes the unbalanced CPU hotplug enable in CPU PM notifier.
Signed-off-by: Lianwei Wang
Signed-off-by: Rafael J. Wysocki
23 Mar, 2016
1 commit
-
Use the more common logging method with the eventual goal of removing
pr_warning altogether.Miscellanea:
- Realign arguments
- Coalesce formats
- Add missing space between a few coalesced formatsSigned-off-by: Joe Perches
Acked-by: Rafael J. Wysocki [kernel/power/suspend.c]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Feb, 2016
1 commit
-
replacing printk(s) with appropriate pr_info and pr_err
in order to fix checkpatch.pl warningsSigned-off-by: Saurabh Sengar
Acked-by: Pavel Machek
Signed-off-by: Rafael J. Wysocki
14 Oct, 2015
1 commit
-
There are quite a few cases in which device drivers, bus types or
even the PM core itself may benefit from knowing whether or not
the platform firmware will be involved in the upcoming system power
transition (during system suspend) or whether or not it was involved
in it (during system resume).For this reason, introduce global system suspend flags that can be
used by the platform code to expose that information for the benefit
of the other parts of the kernel and make the ACPI core set them
as appropriate.Users of the new flags will be added later.
Signed-off-by: Rafael J. Wysocki
01 Aug, 2015
1 commit
-
The Linux kernel suspend path has traditionally invoked sys_sync()
before freezing user threads.But sys_sync() can be expensive, and some user-space OS's do not want
the kernel to pay the cost of sys_sync() on every suspend -- preferring
invoke sync() from user-space if/when they want it.So make sys_sync on suspend build-time optional.
The default is unchanged.
Signed-off-by: Len Brown
Signed-off-by: Rafael J. Wysocki
19 May, 2015
1 commit
-
If a wakeup source is found to be pending in the last stage of
suspend after syscore suspend, then the machine won't suspend, but
suspend_enter() will return 0. That is confusing, as wakeup detection
elsewhere causes -EBUSY to be returned from suspend_enter().To avoid the confusion, make suspend_enter() return -EBUSY in that
case too.Signed-off-by: Ruchi Kandoi
[ rjw: Subject and changelog ]
Signed-off-by: Rafael J. Wysocki
13 May, 2015
1 commit
-
Some of the system suspend diagnostic messages related to
suspend-to-idle refer to it as "freeze sleep" or "freeze state"
while the others say "suspend-to-idle". To reduce the possible
confusion that may result from that, refine the former either to
say "suspend to idle" too or to make it clearer that what is printed
is a state string written to /sys/power/state ("mem", "standby",
or "freeze").Signed-off-by: Rafael J. Wysocki
26 Feb, 2015
1 commit
-
When CONFIG_PM_DEBUG=y, we provide a sysfs file (/sys/power/pm_test) for
selecting one of a few suspend test modes, where rather than entering a
full suspend state, the kernel will perform some subset of suspend
steps, wait 5 seconds, and then resume back to normal operation.This mode is useful for (among other things) observing the state of the
system just before entering a sleep mode, for debugging or analysis
purposes. However, a constant 5 second wait is not sufficient for some
sorts of analysis; for example, on an SoC, one might want to use
external tools to probe the power states of various on-chip controllers
or clocks.This patch turns this 5 second delay into a configurable module
parameter, so users can determine how long to wait in this
pseudo-suspend state before resuming the system.Example (wait 30 seconds);
# echo 30 > /sys/module/suspend/parameters/pm_test_delay
# echo core > /sys/power/pm_test
# time echo mem > /sys/power/state
...
[ 17.583625] suspend debug: Waiting for 30 second(s).
...
real 0m30.381s
user 0m0.017s
sys 0m0.080sSigned-off-by: Brian Norris
Acked-by: Pavel Machek
Reviewed-by: Kevin Cernekee
Acked-by: Florian Fainelli
Signed-off-by: Rafael J. Wysocki
14 Feb, 2015
1 commit
-
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)
09 Nov, 2014
1 commit
-
If no freeze_ops is set, trying to enter suspend-to-IDLE will cause a
nice oops in platform_suspend_prepare_late(). Add respective checks to
platform_suspend_prepare_late() and platform_resume_early() functions.Fixes: a8d46b9e4e48 (ACPI / sleep: Rework the handling of ACPI GPE wakeup ...)
Signed-off-by: Dmitry Eremin-Solenikov
Signed-off-by: Rafael J. Wysocki
01 Oct, 2014
3 commits
-
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
-
Rename several local functions related to platform handling during
system suspend resume in suspend.c so that their names better
reflect their roles.Signed-off-by: Rafael J. Wysocki
-
Subsequent change sets will add platform-related operations between
dpm_suspend_late() and dpm_suspend_noirq() as well as between
dpm_resume_noirq() and dpm_resume_early() in suspend_enter(), so
export these functions for suspend_enter() to be able to call them
separately and split the invocations of dpm_suspend_end() and
dpm_resume_start() in there accordingly.Signed-off-by: Rafael J. Wysocki
22 Sep, 2014
1 commit
-
This patch adds another suspend_resume trace event for analyze_suspend
to capture. The resume_console call can take several hundred milliseconds
if the printk buffer is full of debug info. The tool will now inform
testers of the wasted time and encourage them to disable it in
production builds.Signed-off-by: Todd Brandt
Signed-off-by: Rafael J. Wysocki
03 Sep, 2014
1 commit
-
After commit d431cbc53cb7 (PM / sleep: Simplify sleep states sysfs
interface code) the pm_states[] array is not populated initially,
which causes setup_test_suspend() to always fail and the suspend
testing during boot doesn't work any more.Fix the problem by using pm_labels[] instead of pm_states[] in
setup_test_suspend() and storing a pointer to the label of the
sleep state to test rather than the number representing it,
because the connection between the state numbers and labels is
only established by suspend_set_ops().Fixes: d431cbc53cb7 (PM / sleep: Simplify sleep states sysfs interface code)
Reported-by: Srinivas Pandruvada
Signed-off-by: Rafael J. Wysocki
07 Aug, 2014
1 commit
-
Pull ACPI and power management updates from Rafael Wysocki:
"Again, ACPICA leads the pack (47 commits), followed by cpufreq (18
commits) and system suspend/hibernation (9 commits).From the new code perspective, the ACPICA update brings ACPI 5.1 to
the table, including a new device configuration object called _DSD
(Device Specific Data) that will hopefully help us to operate device
properties like Device Trees do (at least to some extent) and changes
related to supporting ACPI on ARM.Apart from that we have hibernation changes making it use radix trees
to store memory bitmaps which should speed up some operations carried
out by it quite significantly. We also have some power management
changes related to suspend-to-idle (the "freeze" sleep state) support
and more preliminary changes needed to support ACPI on ARM (outside of
ACPICA).The rest is fixes and cleanups pretty much everywhere.
Specifics:
- ACPICA update to upstream version 20140724. That includes ACPI 5.1
material (support for the _CCA and _DSD predefined names, changes
related to the DMAR and PCCT tables and ARM support among other
things) and cleanups related to using ACPICA's header files. A
major part of it is related to acpidump and the core code used by
that utility. Changes from Bob Moore, David E Box, Lv Zheng,
Sascha Wildner, Tomasz Nowicki, Hanjun Guo.- Radix trees for memory bitmaps used by the hibernation core from
Joerg Roedel.- Support for waking up the system from suspend-to-idle (also known
as the "freeze" sleep state) using ACPI-based PCI wakeup signaling
(Rafael J Wysocki).- Fixes for issues related to ACPI button events (Rafael J Wysocki).
- New device ID for an ACPI-enumerated device included into the
Wildcat Point PCH from Jie Yang.- ACPI video updates related to backlight handling from Hans de Goede
and Linus Torvalds.- Preliminary changes needed to support ACPI on ARM from Hanjun Guo
and Graeme Gregory.- ACPI PNP core cleanups from Arjun Sreedharan and Zhang Rui.
- Cleanups related to ACPI_COMPANION() and ACPI_HANDLE() macros
(Rafael J Wysocki).- ACPI-based device hotplug cleanups from Wei Yongjun and Rafael J
Wysocki.- Cleanups and improvements related to system suspend from Lan
Tianyu, Randy Dunlap and Rafael J Wysocki.- ACPI battery cleanup from Wei Yongjun.
- cpufreq core fixes from Viresh Kumar.
- Elimination of a deadband effect from the cpufreq ondemand governor
and intel_pstate driver cleanups from Stratos Karafotis.- 350MHz CPU support for the powernow-k6 cpufreq driver from Mikulas
Patocka.- Fix for the imx6 cpufreq driver from Anson Huang.
- cpuidle core and governor cleanups from Daniel Lezcano, Sandeep
Tripathy and Mohammad Merajul Islam Molla.- Build fix for the big_little cpuidle driver from Sachin Kamat.
- Configuration fix for the Operation Performance Points (OPP)
framework from Mark Brown.- APM cleanup from Jean Delvare.
- cpupower utility fixes and cleanups from Peter Senna Tschudin,
Andrey Utkin, Himangi Saraogi, Rickard Strandqvist, Thomas
Renninger"* tag 'pm+acpi-3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (118 commits)
ACPI / LPSS: add LPSS device for Wildcat Point PCH
ACPI / PNP: Replace faulty is_hex_digit() by isxdigit()
ACPICA: Update version to 20140724.
ACPICA: ACPI 5.1: Update for PCCT table changes.
ACPICA/ARM: ACPI 5.1: Update for GTDT table changes.
ACPICA/ARM: ACPI 5.1: Update for MADT changes.
ACPICA/ARM: ACPI 5.1: Update for FADT changes.
ACPICA: ACPI 5.1: Support for the _CCA predifined name.
ACPICA: ACPI 5.1: New notify value for System Affinity Update.
ACPICA: ACPI 5.1: Support for the _DSD predefined name.
ACPICA: Debug object: Add current value of Timer() to debug line prefix.
ACPICA: acpihelp: Add UUID support, restructure some existing files.
ACPICA: Utilities: Fix local printf issue.
ACPICA: Tables: Update for DMAR table changes.
ACPICA: Remove some extraneous printf arguments.
ACPICA: Update for comments/formatting. No functional changes.
ACPICA: Disassembler: Add support for the ToUUID opererator (macro).
ACPICA: Remove a redundant cast to acpi_size for ACPI_OFFSET() macro.
ACPICA: Work around an ancient GCC bug.
ACPI / processor: Make it possible to get local x2apic id via _MAT
...
05 Aug, 2014
1 commit
-
Pull tracing updates from Steven Rostedt:
"This pull request has a lot of work done. The main thing is the
changes to the ftrace function callback infrastructure. It's
introducing a way to allow different functions to call directly
different trampolines instead of all calling the same "mcount" one.The only user of this for now is the function graph tracer, which
always had a different trampoline, but the function tracer trampoline
was called and did basically nothing, and then the function graph
tracer trampoline was called. The difference now, is that the
function graph tracer trampoline can be called directly if a function
is only being traced by the function graph trampoline. If function
tracing is also happening on the same function, the old way is still
done.The accounting for this takes up more memory when function graph
tracing is activated, as it needs to keep track of which functions it
uses. I have a new way that wont take as much memory, but it's not
ready yet for this merge window, and will have to wait for the next
one.Another big change was the removal of the ftrace_start/stop() calls
that were used by the suspend/resume code that stopped function
tracing when entering into suspend and resume paths. The stop of
ftrace was done because there was some function that would crash the
system if one called smp_processor_id()! The stop/start was a big
hammer to solve the issue at the time, which was when ftrace was first
introduced into Linux. Now ftrace has better infrastructure to debug
such issues, and I found the problem function and labeled it with
"notrace" and function tracing can now safely be activated all the way
down into the guts of suspend and resumeOther changes include clean ups of uprobe code, clean up of the
trace_seq() code, and other various small fixes and clean ups to
ftrace and tracing"* tag 'trace-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits)
ftrace: Add warning if tramp hash does not match nr_trampolines
ftrace: Fix trampoline hash update check on rec->flags
ring-buffer: Use rb_page_size() instead of open coded head_page size
ftrace: Rename ftrace_ops field from trampolines to nr_trampolines
tracing: Convert local function_graph functions to static
ftrace: Do not copy old hash when resetting
tracing: let user specify tracing_thresh after selecting function_graph
ring-buffer: Always run per-cpu ring buffer resize with schedule_work_on()
tracing: Remove function_trace_stop and HAVE_FUNCTION_TRACE_MCOUNT_TEST
s390/ftrace: remove check of obsolete variable function_trace_stop
arm64, ftrace: Remove check of obsolete variable function_trace_stop
Blackfin: ftrace: Remove check of obsolete variable function_trace_stop
metag: ftrace: Remove check of obsolete variable function_trace_stop
microblaze: ftrace: Remove check of obsolete variable function_trace_stop
MIPS: ftrace: Remove check of obsolete variable function_trace_stop
parisc: ftrace: Remove check of obsolete variable function_trace_stop
sh: ftrace: Remove check of obsolete variable function_trace_stop
sparc64,ftrace: Remove check of obsolete variable function_trace_stop
tile: ftrace: Remove check of obsolete variable function_trace_stop
ftrace: x86: Remove check of obsolete variable function_trace_stop
...
23 Jul, 2014
1 commit
-
After the introduction of freeze_ops it makes more sense to move
all of the platform suspend operations to separate functions that
each will do all of the necessary checks and choose the right
callback to execute istead of doing all that in the core code
which makes it generally harder to follow.Signed-off-by: Rafael J. Wysocki
21 Jul, 2014
1 commit
-
Simplify the sleep states sysfs interface /sys/power/state code by
redefining pm_states[] as an array of pointers to constant strings
such that only the entries corresponding to valid states are set.Signed-off-by: Rafael J. Wysocki
17 Jul, 2014
1 commit
-
ftrace_stop() and ftrace_start() were added to the suspend and hibernate
process because there was some function within the work flow that caused
the system to reboot if it was traced. This function has recently been
found (restore_processor_state()). Now there's no reason to disable
function tracing while we are going into suspend or hibernate, which means
that being able to trace this will help tremendously in debugging any
issues with suspend or hibernate.This also means that the ftrace_stop/start() functions can be removed
and simplify the function tracing code a bit.Link: http://lkml.kernel.org/r/1518201.VD9cU33jRU@vostro.rjw.lan
Acked-by: "Rafael J. Wysocki"
Reviewed-by: Masami Hiramatsu
Signed-off-by: Steven Rostedt
15 Jul, 2014
1 commit
-
This patch fixes a NULL pointer dereference issue introduced by
commit 1f0b63866fc1 (ACPI / PM: Hold ACPI scan lock over the "freeze"
sleep state).Fixes: 1f0b63866fc1 (ACPI / PM: Hold ACPI scan lock over the "freeze" sleep state)
Link: http://marc.info/?l=linux-pm&m=140541182017443&w=2
Reported-and-tested-by: Alexander Stein
Signed-off-by: Zhang Rui
Signed-off-by: Rafael J. Wysocki
07 Jun, 2014
2 commits
-
Adds trace events that give finer resolution into suspend/resume. These
events are graphed in the timelines generated by the analyze_suspend.py
script. They represent large areas of time consumed that are typical to
suspend and resume.The event is triggered by calling the function "trace_suspend_resume"
with three arguments: a string (the name of the event to be displayed
in the timeline), an integer (case specific number, such as the power
state or cpu number), and a boolean (where true is used to denote the start
of the timeline event, and false to denote the end).The suspend_resume trace event reproduces the data that the machine_suspend
trace event did, so the latter has been removed.Signed-off-by: Todd Brandt
Acked-by: Steven Rostedt
Signed-off-by: Rafael J. Wysocki
26 May, 2014
3 commits
-
On some systems the platform doesn't support neither
PM_SUSPEND_MEM nor PM_SUSPEND_STANDBY, so PM_SUSPEND_FREEZE is the
only available system sleep state. However, some user space frameworks
only use the "mem" and (sometimes) "standby" sleep state labels, so
the users of those systems need to modify user space in order to be
able to use system suspend at all and that is not always possible.For this reason, add a new kernel command line argument,
relative_sleep_states, allowing the users of those systems to change
the way in which the kernel assigns labels to system sleep states.
Namely, for relative_sleep_states=1, the "mem", "standby" and "freeze"
labels will enumerate the available system sleem states from the
deepest to the shallowest, respectively, so that "mem" is always
present in /sys/power/state and the other state strings may or may
not be presend depending on what is supported by the platform.Update system sleep states documentation to reflect this change.
Signed-off-by: Rafael J. Wysocki
-
Use the observation that, for platform-dependent sleep states
(PM_SUSPEND_STANDBY, PM_SUSPEND_MEM), a given state is either
always supported or always unsupported and store that information
in pm_states[] instead of calling valid_state() every time we
need to check it.Also do not use valid_state() for PM_SUSPEND_FREEZE, which is always
valid, and move the pm_test_level validity check for PM_SUSPEND_FREEZE
directly into enter_state().Signed-off-by: Rafael J. Wysocki
-
To allow sleep states corresponding to the "mem", "standby" and
"freeze" lables to be different from the pm_states[] indexes of
those strings, introduce struct pm_sleep_state, consisting of
a string label and a state number, and turn pm_states[] into an
array of objects of that type.This modification should not lead to any functional changes.
Signed-off-by: Rafael J. Wysocki
20 May, 2014
1 commit
16 May, 2014
1 commit
-
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
07 May, 2014
1 commit
-
If freeze_enter() is called, we want to bypass the current cpuidle
governor and always use the deepest available (that is, not disabled)
C-state, because we want to save as much energy as reasonably possible
then and runtime latency constraints don't matter at that point, since
the system is in a sleep state anyway.Signed-off-by: Rafael J. Wysocki
Tested-by: Aubrey Li
22 Apr, 2014
1 commit
-
The "freeze" system sleep state introduced by commit 7e73c5ae6e79
(PM: Introduce suspend state PM_SUSPEND_FREEZE) requires cpuidle
to be functional when freeze_enter() is executed to work correctly
(that is, to be able to save any more energy than runtime idle),
but that is impossible after commit 8651f97bd951d (PM / cpuidle:
System resume hang fix with cpuidle) which caused cpuidle to be
paused in dpm_suspend_noirq() and resumed in dpm_resume_noirq().To avoid that problem, add cpuidle_resume() and cpuidle_pause()
to the beginning and the end of freeze_enter(), respectively.Reported-by: Zhang Rui
Signed-off-by: Rafael J. Wysocki
Reviewed-by: Preeti U Murthy
08 Apr, 2014
1 commit
-
To increase compiler portability there is which
provides convenience macros for various gcc constructs. Eg: __weak for
__attribute__((weak)). I've replaced all instances of gcc attributes
with the right macro in the kernel subsystem.Signed-off-by: Gideon Israel Dsouza
Cc: "Rafael J. Wysocki"
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Mar, 2014
1 commit
-
Double ! or !! are normally required to get 0 or 1 out of a expression. A
comparision always returns 0 or 1 and hence there is no need to apply double !
over it again.Signed-off-by: Viresh Kumar
Signed-off-by: Rafael J. Wysocki
26 Jul, 2013
1 commit
-
Change where ftrace is disabled and re-enabled during system
suspend/resume to allow tracing of device driver pm callbacks.
Ftrace will now be turned off when suspend reaches
disable_nonboot_cpus() instead of at the very beginning of system
suspend.Ftrace was disabled during suspend/resume back in 2008 by
Steven Rostedt as he discovered there was a conflict in the
enable_nonboot_cpus() call (see commit f42ac38 "ftrace: disable
tracing for suspend to ram"). This change preserves his fix by
disabling ftrace, but only at the function where it is known
to cause problems.The new change allows tracing of the device level code for better
debug.[rjw: Changelog]
Signed-off-by: Todd Brandt
Signed-off-by: Rafael J. Wysocki
12 Jun, 2013
1 commit
-
This adds in a new message to the wakeup code which adds an
indication to the log that suspend was cancelled due to a wake event
occouring during the suspend sequence. It also adjusts the message
printed in suspend.c to reflect the potential that a suspend was
aborted, as opposed to a device failing to suspend.Without these message adjustments one can end up with a kernel log
that says that a device failed to suspend with no actual device
suspend failures, which can be confusing to the log examiner.Signed-off-by: Bernie Thompson
Signed-off-by: Rafael J. Wysocki
05 Apr, 2013
2 commits
-
freeze state is a software suspend state that does not run into
low-level platform callbacks which may interact with BIOS.
And freeze state does not need to disable the processors.But the current pm_test support misleads users because users
can enter freeze state with pm_test set to TEST_CPUS/TEST_CORE,
while this pm_test setting never takes actions.So, invalidate TEST_CPUS/TEST_CORE for freeze state in this patch.
Then users will get an error instead, when trying to
enter freeze state with pm_test mode set to TEST_CPUS/TEST_CORE.Signed-off-by: Zhang Rui
Signed-off-by: Rafael J. Wysocki -
Invoke freeze_enter() after suspend_test(TEST_PLATFORM) being invoked.
So when setting /sys/power/pm_test to "platform", it can be used to
check if freeze state is working well after all devices are suspended
and before processors are blocked,Signed-off-by: Zhang Rui
Signed-off-by: Rafael J. Wysocki
10 Feb, 2013
1 commit
-
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:
0.5~0.9WAverage 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
09 Aug, 2012
1 commit
-
Revert commit 45226e9 (NMI watchdog: fix for lockup detector breakage
on resume) which breaks resume from system suspend on my SH7372
Mackerel board (by causing a NULL pointer dereference to happen) and
is generally wrong, because it abuses the CPU hotplug functionality
in a shamelessly blatant way.The original issue should be addressed through appropriate syscore
resume callback instead.Signed-off-by: Rafael J. Wysocki
