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  1. 08 Dec, 2011 1 commit
  3. 23 Nov, 2011 1 commit
  5. 19 Nov, 2011 1 commit
  7. 31 Oct, 2011 1 commit
  9. 16 Oct, 2011 2 commits
    • Rafael J. Wysocki's avatar
      PM: Fix build issue in main.c for CONFIG_PM_SLEEP unset · ca123102
      Rafael J. Wysocki authored 
      Suspend statistics should depend on CONFIG_PM_SLEEP, so make that
happen.
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
      ca123102
    • ShuoX Liu's avatar
      PM / Suspend: Add statistics debugfs file for suspend to RAM · 2a77c46d
      ShuoX Liu authored 
      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: default avatarShuoX Liu <shuox.liu@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
      2a77c46d
  11. 15 Jul, 2011 1 commit
  13. 17 May, 2011 1 commit
    • Rafael J. Wysocki's avatar
      PM / Hibernate: Add sysfs knob to control size of memory for drivers · ddeb6487
      Rafael J. Wysocki authored 
      Martin reports that on his system hibernation occasionally fails due
to the lack of memory, because the radeon driver apparently allocates
too much of it during the device freeze stage.  It turns out that the
amount of memory allocated by radeon during hibernation (and
presumably during system suspend too) depends on the utilization of
the GPU (e.g. hibernating while there are two KDE 4 sessions with
compositing enabled causes radeon to allocate more memory than for
one KDE 4 session).

In principle it should be possible to use image_size to make the
memory preallocation mechanism free enough memory for the radeon
driver, but in practice it is not easy to guess the right value
because of the way the preallocation code uses image_size.  For this
reason, it seems reasonable to allow users to control the amount of
memory reserved for driver allocations made after the hibernate
preallocation, which currently is constant and amounts to 1 MB.

Introduce a new sysfs file, /sys/power/reserved_size, whose value
will be used as the amount of memory to reserve for the
post-preallocation reservations made by device drivers, in bytes.
For backwards compatibility, set its default (and initial) value to
the currently used number (1 MB).

References: https://bugzilla.kernel.org/show_bug.cgi?id=34102Reported-and-tested-by: default avatarMartin Steigerwald <Martin@Lichtvoll.de>
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
      ddeb6487
  15. 31 Mar, 2011 1 commit
  17. 14 Mar, 2011 2 commits
  19. 16 Feb, 2011 1 commit
  21. 16 Oct, 2010 4 commits
    • James Hogan's avatar
      PM: Add sysfs attr for rechecking dev hash from PM trace · d33ac60b
      James Hogan authored 
      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: default avatarJames Hogan <james@albanarts.com>
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
      d33ac60b
    • Rafael J. Wysocki's avatar
      PM / Wakeup: Introduce wakeup source objects and event statistics (v3) · 074037ec
      Rafael J. Wysocki authored 
      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: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      074037ec
    • Rafael J. Wysocki's avatar
      PM / Hibernate: Make default image size depend on total RAM size · ac5c24ec
      Rafael J. Wysocki authored 
      The default hibernation image size is currently hard coded and euqal
to 500 MB, which is not a reasonable default on many contemporary
systems.  Make it equal 2/5 of the total RAM size (this is slightly
below the maximum, i.e. 1/2 of the total RAM size, and seems to be
generally suitable).
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Tested-by: default avatarM. Vefa Bicakci <bicave@superonline.com>
      ac5c24ec
    • Rafael J. Wysocki's avatar
      PM / Runtime: Use alloc_workqueue() for creating the PM workqueue · bcb5ba8b
      Rafael J. Wysocki authored 
      Although we need the PM workqueue to be freezable, we don't need it
to be singlethread.  Also, the number of concurrent work items
running on a single CPU need not be constrained.  For these reasons
use alloc_workqueue() directly, with suitable arguments, instead of
create_freezeable_workqueue(), to create the runtime PM workqueue.
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarTejun Heo <tj@kernel.org>
      bcb5ba8b
  23. 18 Jul, 2010 1 commit
    • Rafael J. Wysocki's avatar
      PM: Make it possible to avoid races between wakeup and system sleep · c125e96f
      Rafael J. Wysocki authored 
      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: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Acked-by: default avatarmarkgross <markgross@thegnar.org>
Reviewed-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      c125e96f
  25. 26 Feb, 2010 1 commit
  27. 06 Dec, 2009 1 commit
  29. 22 Aug, 2009 1 commit
    • Rafael J. Wysocki's avatar
      PM: Introduce core framework for run-time PM of I/O devices (rev. 17) · 5e928f77
      Rafael J. Wysocki authored 
      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: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarMagnus Damm <damm@igel.co.jp>
      5e928f77
  31. 12 Jun, 2009 4 commits
  33. 24 May, 2009 1 commit
    • Rafael J. Wysocki's avatar
      PM: Do not hold dpm_list_mtx while disabling/enabling nonboot CPUs · 32bdfac5
      Rafael J. Wysocki authored 
      We shouldn't hold dpm_list_mtx while executing
[disable|enable]_nonboot_cpus(), because theoretically this may lead
to a deadlock as shown by the following example (provided by Johannes
Berg):

CPU 3       CPU 2                     CPU 1
                                      suspend/hibernate
            something:
            rtnl_lock()               device_pm_lock()
                                       -> mutex_lock(&dpm_list_mtx)

            mutex_lock(&dpm_list_mtx)

linkwatch_work
 -> rtnl_lock()
                                      disable_nonboot_cpus()
                                       -> flush CPU 3 workqueue

Fortunately, device drivers are supposed to stop any activities that
might lead to the registration of new device objects way before
disable_nonboot_cpus() is called, so it shouldn't be necessary to
hold dpm_list_mtx over the entire late part of device suspend and
early part of device resume.

Thus, during the late suspend and the early resume of devices acquire
dpm_list_mtx only when dpm_list is going to be traversed and release
it right after that.

This patch is reported to fix the regressions tracked as
http://bugzilla.kernel.org/show_bug.cgi?id=13245.
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Reported-by: default avatarMiles Lane <miles.lane@gmail.com>
Tested-by: default avatarMing Lei <tom.leiming@gmail.com>
      32bdfac5
  35. 19 Apr, 2009 1 commit
    • Rafael J. Wysocki's avatar
      PM/Suspend: Introduce two new platform callbacks to avoid breakage · 6a7c7eaf
      Rafael J. Wysocki authored 
      Commit 900af0d9 (PM: Change suspend
code ordering) changed the ordering of suspend code in such a way
that the platform .prepare() callback is now executed after the
device drivers' late suspend callbacks have run.  Unfortunately, this
turns out to break ARM platforms that need to talk via I2C to power
control devices during the .prepare() callback.

For this reason introduce two new platform suspend callbacks,
.prepare_late() and .wake(), that will be called just prior to
disabling non-boot CPUs and right after bringing them back on line,
respectively, and use them instead of .prepare() and .finish() for
ACPI suspend.  Make the PM core execute the .prepare() and .finish()
platform suspend callbacks where they were executed previously (that
is, right after calling the regular suspend methods provided by
device drivers and right before executing their regular resume
methods, respectively).

It is not necessary to make analogous changes to the hibernation
code and data structures at the moment, because they are only used
by ACPI platforms.
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Reported-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: default avatarLen Brown <len.brown@intel.com>
      6a7c7eaf
  37. 30 Mar, 2009 2 commits
    • Rafael J. Wysocki's avatar
      PM: Change suspend code ordering · 900af0d9
      Rafael J. Wysocki authored 
      Change the ordering of the suspend core code so that the platform
"prepare" callback is executed and the nonboot CPUs are disabled
after calling device drivers' "late suspend" methods.

This change will allow us to rework the PCI PM core so that the power
state of devices is changed in the "late" phase of suspend (and
analogously in the "early" phase of resume), which in turn will allow
us to avoid the race condition where a device using shared interrupts
is put into a low power state with interrupts enabled and then an
interrupt (for another device) comes in and confuses its driver.
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
      900af0d9
    • Rafael J. Wysocki's avatar
      PM: Rework handling of interrupts during suspend-resume · 2ed8d2b3
      Rafael J. Wysocki authored 
      Use the functions introduced in by the previous patch,
suspend_device_irqs(), resume_device_irqs() and check_wakeup_irqs(),
to rework the handling of interrupts during suspend (hibernation) and
resume.  Namely, interrupts will only be disabled on the CPU right
before suspending sysdevs, while device drivers will be prevented
from receiving interrupts, with the help of the new helper function,
before their "late" suspend callbacks run (and analogously during
resume).

In addition, since the device interrups are now disabled before the
CPU has turned all interrupts off and the CPU will ACK the interrupts
setting the IRQ_PENDING bit for them, check in sysdev_suspend() if
any wake-up interrupts are pending and abort suspend if that's the
case.
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
      2ed8d2b3
  39. 22 Feb, 2009 1 commit
  41. 16 Jan, 2009 1 commit
  43. 06 Jan, 2009 1 commit
  45. 23 Nov, 2008 1 commit
  47. 18 Nov, 2008 1 commit
  49. 16 Oct, 2008 1 commit
  51. 27 Aug, 2008 1 commit
    • Steven Rostedt's avatar
      ftrace: disable tracing for suspend to ram · f42ac38c
      Steven Rostedt authored 
      I've been painstakingly debugging the issue with suspend to ram and
ftraced. The 2.6.28 code does not have this issue, but since the mcount
recording is not going to be in 27, this must be solved for the ftrace
daemon version.

The resume from suspend to ram would reboot because it was triple
faulting. Debugging further, I found that calling the mcount function
itself was not an issue, but it would fault when it incremented
preempt_count. preempt_count is on the tasks info structure that is on the
low memory address of the task's stack.  For some reason, it could not
write to it. Resuming out of suspend to ram does quite a lot of funny
tricks to get to work, so it is not surprising at all that simply doing a
preempt_disable() would cause a fault.

Thanks to Rafael for suggesting to add a "while (1);" to find the place in
resuming that is causing the fault. I would place the loop somewhere in
the code, compile and reboot and see if it would either reboot (hit the
fault) or simply hang (hit the loop).  Doing this over and over again, I
narrowed it down that it was happening in enable_nonboot_cpus.

At this point, I found that it is easier to simply disable tracing around
the suspend code, instead of searching for the particular function that
can not handle doing a preempt_disable.

This patch disables the tracer as it suspends and reenables it on resume.

I tested this patch on my Laptop, and it can resume fine with the patch.
Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Acked-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f42ac38c
  53. 26 Jul, 2008 1 commit
  55. 24 Jul, 2008 1 commit
    • David Brownell's avatar
      pm: boot time suspend selftest · 77437fd4
      David Brownell authored 
      Boot-time test for system suspend states (STR or standby).  The generic
RTC framework triggers wakeup alarms, which are used to exit those states.

  - Measures some aspects of suspend time ... this uses "jiffies" until
    someone converts it to use a timebase that works properly even while
    timer IRQs are disabled.

  - Triggered by a command line parameter.  By default nothing even
    vaguely troublesome will happen, but "test_suspend=mem" will give
    you a brief STR test during system boot.  (Or you may need to use
    "test_suspend=standby" instead, if your hardware needs that.)

This isn't without problems.  It fires early enough during boot that for
example both PCMCIA and MMC stacks have misbehaved.  The workaround in
those cases was to boot without such media cards inserted.

[matthltc@us.ibm.com: fix compile failure in boot time suspend selftest]
Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Machek <pavel@suse.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: default avatarMatt Helsley <matthltc@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      77437fd4
  57. 12 Jun, 2008 1 commit
    • Rafael J. Wysocki's avatar
      Suspend-related patches for 2.6.27 · d8f3de0d
      Rafael J. Wysocki authored 
      ACPI PM: Add possibility to change suspend sequence

There are some systems out there that don't work correctly with
our current suspend/hibernation code ordering.  Provide a workaround
for these systems allowing them to pass 'acpi_sleep=old_ordering' in
the kernel command line so that it will use the pre-ACPI 2.0 ("old")
suspend code ordering.

Unfortunately, this requires us to add a platform hook to the
resuming of devices for recovering the platform in case one of the
device drivers' .suspend() routines returns error code.  Namely,
ACPI 1.0 specifies that _PTS should be called before suspending
devices, but _WAK still should be called before resuming them in
order to undo the changes made by _PTS.  However, if there is an
error during suspending devices, they are automatically resumed
without returning control to the PM core, so the _WAK has to be
called from within device_resume() in that cases.

The patch also reorders and refactors the ACPI suspend/hibernation
code to avoid duplication as far as reasonably possible.
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarPavel Machek <pavel@suse.cz>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
      d8f3de0d
  59. 10 Jun, 2008 1 commit
    • Rafael J. Wysocki's avatar
      Introduce new top level suspend and hibernation callbacks · 1eede070
      Rafael J. Wysocki authored 
      Introduce 'struct pm_ops' and 'struct pm_ext_ops' ('ext' meaning
'extended') representing suspend and hibernation operations for bus
types, device classes, device types and device drivers.

Modify the PM core to use 'struct pm_ops' and 'struct pm_ext_ops'
objects, if defined, instead of the ->suspend(), ->resume(),
->suspend_late(), and ->resume_early() callbacks (the old callbacks
will be considered as legacy and gradually phased out).

The main purpose of doing this is to separate suspend (aka S2RAM and
standby) callbacks from hibernation callbacks in such a way that the
new callbacks won't take arguments and the semantics of each of them
will be clearly specified.  This has been requested for multiple
times by many people, including Linus himself, and the reason is that
within the current scheme if ->resume() is called, for example, it's
difficult to say why it's been called (ie. is it a resume from RAM or
from hibernation or a suspend/hibernation failure etc.?).

The second purpose is to make the suspend/hibernation callbacks more
flexible so that device drivers can handle more than they can within
the current scheme.  For example, some drivers may need to prevent
new children of the device from being registered before their
->suspend() callbacks are executed or they may want to carry out some
operations requiring the availability of some other devices, not
directly bound via the parent-child relationship, in order to prepare
for the execution of ->suspend(), etc.

Ultimately, we'd like to stop using the freezing of tasks for suspend
and therefore the drivers' suspend/hibernation code will have to take
care of the handling of the user space during suspend/hibernation.
That, in turn, would be difficult within the current scheme, without
the new ->prepare() and ->complete() callbacks.
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
      1eede070
  61. 01 Feb, 2008 1 commit
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