Commit Graph

1088 Commits

Author SHA1 Message Date
Ingo Molnar b395fb36d5 Merge branch 'iommu-3.1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu into core/iommu 2011-07-07 12:58:28 +02:00
Alan Stern 69c843b45e PM / Runtime: Prevent runtime_resume from racing with probe
This patch (as1475) adds device_lock() and device_unlock() calls to
the store methods for the power/control and power/autosuspend_delay_ms
sysfs attribute files.  We don't want badly timed writes to these
files to cause runtime_resume callbacks to occur while a driver is
being probed for a device.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-06 10:52:23 +02:00
Rafael J. Wysocki 62052ab1d1 PM / Runtime: Replace "run-time" with "runtime" in documentation
The runtime PM documentation and kerneldoc comments sometimes spell
"runtime" with a dash (i.e. "run-time").  Replace all of those
instances with "runtime" to make the naming consistent.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-06 10:52:13 +02:00
Rafael J. Wysocki 1e2ef05bb8 PM: Limit race conditions between runtime PM and system sleep (v2)
One of the roles of the PM core is to prevent different PM callbacks
executed for the same device object from racing with each other.
Unfortunately, after commit e866500247
(PM: Allow pm_runtime_suspend() to succeed during system suspend)
runtime PM callbacks may be executed concurrently with system
suspend/resume callbacks for the same device.

The main reason for commit e866500247
was that some subsystems and device drivers wanted to use runtime PM
helpers, pm_runtime_suspend() and pm_runtime_put_sync() in
particular, for carrying out the suspend of devices in their
.suspend() callbacks.  However, as it's been determined recently,
there are multiple reasons not to do so, inlcuding:

 * The caller really doesn't control the runtime PM usage counters,
   because user space can access them through sysfs and effectively
   block runtime PM.  That means using pm_runtime_suspend() or
   pm_runtime_get_sync() to suspend devices during system suspend
   may or may not work.

 * If a driver calls pm_runtime_suspend() from its .suspend()
   callback, it causes the subsystem's .runtime_suspend() callback to
   be executed, which leads to the call sequence:

   subsys->suspend(dev)
      driver->suspend(dev)
         pm_runtime_suspend(dev)
            subsys->runtime_suspend(dev)

   recursive from the subsystem's point of view.  For some subsystems
   that may actually work (e.g. the platform bus type), but for some
   it will fail in a rather spectacular fashion (e.g. PCI).  In each
   case it means a layering violation.

 * Both the subsystem and the driver can provide .suspend_noirq()
   callbacks for system suspend that can do whatever the
   .runtime_suspend() callbacks do just fine, so it really isn't
   necessary to call pm_runtime_suspend() during system suspend.

 * The runtime PM's handling of wakeup devices is usually different
   from the system suspend's one, so .runtime_suspend() may simply be
   inappropriate for system suspend.

 * System suspend is supposed to work even if CONFIG_PM_RUNTIME is
   unset.

 * The runtime PM workqueue is frozen before system suspend, so if
   whatever the driver is going to do during system suspend depends
   on it, that simply won't work.

Still, there is a good reason to allow pm_runtime_resume() to
succeed during system suspend and resume (for instance, some
subsystems and device drivers may legitimately use it to ensure that
their devices are in full-power states before suspending them).
Moreover, there is no reason to prevent runtime PM callbacks from
being executed in parallel with the system suspend/resume .prepare()
and .complete() callbacks and the code removed by commit
e866500247 went too far in this
respect.  On the other hand, runtime PM callbacks, including
.runtime_resume(), must not be executed during system suspend's
"late" stage of suspending devices and during system resume's "early"
device resume stage.

Taking all of the above into consideration, make the PM core
acquire a runtime PM reference to every device and resume it if
there's a runtime PM resume request pending right before executing
the subsystem-level .suspend() callback for it.  Make the PM core
drop references to all devices right after executing the
subsystem-level .resume() callbacks for them.  Additionally,
make the PM core disable the runtime PM framework for all devices
during system suspend, after executing the subsystem-level .suspend()
callbacks for them, and enable the runtime PM framework for all
devices during system resume, right before executing the
subsystem-level .resume() callbacks for them.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
2011-07-06 10:51:58 +02:00
Rafael J. Wysocki 632e270e01 PM / Runtime: Return special error code if runtime PM is disabled
Some callers of pm_runtime_get_sync() and other runtime PM helper
functions, scsi_autopm_get_host() and scsi_autopm_get_device() in
particular, need to distinguish error codes returned when runtime PM
is disabled (i.e. power.disable_depth is nonzero for the given
device) from error codes returned in other situations.  For this
reason, make the runtime PM helper functions return -EACCES when
power.disable_depth is nonzero and ensure that this error code
won't be returned by them in any other circumstances.  Modify
scsi_autopm_get_host() and scsi_autopm_get_device() to check the
error code returned by pm_runtime_get_sync() and ignore -EACCES.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-02 14:30:10 +02:00
Rafael J. Wysocki 3d5c30367c PM: Rename clock management functions
The common PM clock management functions may be used for system
suspend/resume as well as for runtime PM, so rename them
accordingly.  Modify kerneldoc comments describing these functions
and kernel messages printed by them, so that they refer to power
management in general rather that to runtime PM.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Kevin Hilman <khilman@ti.com>
2011-07-02 14:29:57 +02:00
Rafael J. Wysocki b7b95920aa PM: Allow the clocks management code to be used during system suspend
The common clocks management code in drivers/base/power/clock_ops.c
is going to be used during system-wide power transitions as well as
for runtime PM, so it shouldn't depend on CONFIG_PM_RUNTIME.
However, the suspend/resume functions provided by it for
CONFIG_PM_RUNTIME unset, to be used during system-wide power
transitions, should not behave in the same way as their counterparts
defined for CONFIG_PM_RUNTIME set, because in that case the clocks
are managed differently at run time.

The names of the functions still contain the word "runtime" after
this change, but that is going to be modified by a separate patch
later.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Kevin Hilman <khilman@ti.com>
2011-07-02 14:29:56 +02:00
Rafael J. Wysocki d4f2d87a8b PM / Domains: Wakeup devices support for system sleep transitions
There is the problem how to handle devices set up to wake up the
system from sleep states during system-wide power transitions.
In some cases, those devices can be turned off entirely, because the
wakeup signals will be generated on their behalf anyway.  In some
other cases, they will generate wakeup signals if their clocks are
stopped, but only if power is not removed from them.  Finally, in
some cases, they can only generate wakeup signals if power is not
removed from them and their clocks are enabled.

To allow platform-specific code to decide whether or not to put
wakeup devices (and their PM domains) into low-power state during
system-wide transitions, such as system suspend, introduce a new
generic PM domain callback, .active_wakeup(), that will be used
during the "noirq" phase of system suspend and hibernation (after
image creation) to decide what to do with wakeup devices.
Specifically, if this callback is present and returns "true", the
generic PM domain code will not execute .stop_device() for the
given wakeup device and its PM domain won't be powered off.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
2011-07-02 14:29:56 +02:00
Rafael J. Wysocki 596ba34bcd PM / Domains: System-wide transitions support for generic domains (v5)
Make generic PM domains support system-wide power transitions
(system suspend and hibernation).  Add suspend, resume, freeze, thaw,
poweroff and restore callbacks to be associated with struct
generic_pm_domain objects and make pm_genpd_init() use them as
appropriate.

The new callbacks do nothing for devices belonging to power domains
that were powered down at run time (before the transition).  For the
other devices the action carried out depends on the type of the
transition.  During system suspend the power domain .suspend()
callback executes pm_generic_suspend() for the device, while the
PM domain .suspend_noirq() callback runs pm_generic_suspend_noirq()
for it, stops it and eventually removes power from the PM domain it
belongs to (after all devices in the domain have been stopped and its
subdomains have been powered off).

During system resume the PM domain .resume_noirq() callback
restores power to the PM domain (when executed for it first time),
starts the device and executes pm_generic_resume_noirq() for it,
while the .resume() callback executes pm_generic_resume() for the
device.  Finally, the .complete() callback executes pm_runtime_idle()
for the device which should put it back into the suspended state if
its runtime PM usage count is equal to zero at that time.

The actions carried out during hibernation and resume from it are
analogous to the ones described above.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Kevin Hilman <khilman@ti.com>
2011-07-02 14:29:56 +02:00
Rafael J. Wysocki 5248051b9a PM / Domains: Move code from under #ifdef CONFIG_PM_RUNTIME (v2)
There is some code in drivers/base/power/domain.c that will be useful
for both runtime PM and system-wide power transitions, so make it
depend on CONFIG_PM instead of CONFIG_PM_RUNTIME.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Kevin Hilman <khilman@ti.com>
2011-07-02 14:29:55 +02:00
Rafael J. Wysocki e529192883 PM: Introduce generic "noirq" callback routines for subsystems (v2)
Introduce generic "noirq" power management callback routines for
subsystems in addition to the "regular" generic PM callback routines.

The new routines will be used, among other things, for implementing
system-wide PM transitions support for generic PM domains.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-02 14:29:55 +02:00
Rafael J. Wysocki f721889ff6 PM / Domains: Support for generic I/O PM domains (v8)
Introduce common headers, helper functions and callbacks allowing
platforms to use simple generic power domains for runtime power
management.

Introduce struct generic_pm_domain to be used for representing
power domains that each contain a number of devices and may be
parent domains or subdomains with respect to other power domains.
Among other things, this structure includes callbacks to be
provided by platforms for performing specific tasks related to
power management (i.e. ->stop_device() may disable a device's
clocks, while ->start_device() may enable them, ->power_off() is
supposed to remove power from the entire power domain
and ->power_on() is supposed to restore it).

Introduce functions that can be used as power domain runtime PM
callbacks, pm_genpd_runtime_suspend() and pm_genpd_runtime_resume(),
as well as helper functions for the initialization of a power
domain represented by a struct generic_power_domain object,
adding a device to or removing a device from it and adding or
removing subdomains.

Introduce configuration option CONFIG_PM_GENERIC_DOMAINS to be
selected by the platforms that want to use the new code.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: Kevin Hilman <khilman@ti.com>
2011-07-02 14:29:55 +02:00
Rafael J. Wysocki 564b905ab1 PM / Domains: Rename struct dev_power_domain to struct dev_pm_domain
The naming convention used by commit 7538e3db6e015e890825fbd9f86599b
(PM: Add support for device power domains), which introduced the
struct dev_power_domain type for representing device power domains,
evidently confuses some developers who tend to think that objects
of this type must correspond to "power domains" as defined by
hardware, which is not the case.  Namely, at the kernel level, a
struct dev_power_domain object can represent arbitrary set of devices
that are mutually dependent power management-wise and need not belong
to one hardware power domain.  To avoid that confusion, rename struct
dev_power_domain to struct dev_pm_domain and rename the related
pointers in struct device and struct pm_clk_notifier_block from
pwr_domain to pm_domain.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
2011-07-02 14:29:54 +02:00
Márton Németh 573c977439 driver core: add more help description for "path to uevent helper"
The kernel configuration UEVENT_HELPER_PATH is a string to
the uevent helper program. Add more description about how
to disable this feature and how to enable it again during
runtime.

Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-07-01 15:12:15 -07:00
matt mooney 156faf9080 driver-core: modify FIRMWARE_IN_KERNEL help message
The help message for the configuration variable was inconsistent
with the way "make firmware_install" really works.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-07-01 15:12:03 -07:00
matt mooney 113647a281 driver-core: Kconfig grammar corrections in firmware configuration
Fix some grammatical errors and reword a few sentences.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-07-01 15:12:02 -07:00
Linus Torvalds c89b857ce6 Merge branch 'driver-core-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* 'driver-core-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  Connector: Correctly set the error code in case of success when dispatching receive callbacks
  Connector: Set the CN_NETLINK_USERS correctly
  pti: PTI semantics fix in pti_tty_cleanup.
  pti: ENXIO error case memory leak PTI fix.
  pti: double-free security PTI fix
  drivers:misc: ti-st: fix skipping of change remote baud
  drivers/base/platform.c: don't mark platform_device_register_resndata() as __init_or_module
  st_kim: Handle case of no device found for ID 0
  firmware: fix GOOGLE_SMI kconfig dependency warning
2011-06-28 11:15:36 -07:00
Rafael J. Wysocki 4d1518f566 PM / Runtime: Handle clocks correctly if CONFIG_PM_RUNTIME is unset
Commit 85eb8c8d0b (PM / Runtime:
Generic clock manipulation rountines for runtime PM (v6)) converted
the shmobile platform to using generic code for runtime PM clock
management, but it changed the behavior for CONFIG_PM_RUNTIME unset
incorrectly.

Specifically, for CONFIG_PM_RUNTIME unset pm_runtime_clk_notify()
should enable clocks for action equal to BUS_NOTIFY_BIND_DRIVER and
it should disable them for action equal to BUS_NOTIFY_UNBOUND_DRIVER
(instead of BUS_NOTIFY_ADD_DEVICE and BUS_NOTIFY_DEL_DEVICE,
respectively).  Make this function behave as appropriate.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
2011-06-21 23:24:33 +02:00
Alan Stern 6d0e0e84f6 PM: Fix async resume following suspend failure
The PM core doesn't handle suspend failures correctly when it comes to
asynchronously suspended devices.  These devices are moved onto the
dpm_suspended_list as soon as the corresponding async thread is
started up, and they remain on the list even if they fail to suspend
or the sleep transition is cancelled before they get suspended.  As a
result, when the PM core unwinds the transition, it tries to resume
the devices even though they were never suspended.

This patch (as1474) fixes the problem by adding a new "is_suspended"
flag to dev_pm_info.  Devices are resumed only if the flag is set.

[rjw:
 * Moved the dev->power.is_suspended check into device_resume(),
   because we need to complete dev->power.completion and clear
   dev->power.is_prepared too for devices whose
   dev->power.is_suspended flags are unset.
 * Fixed __device_suspend() to avoid setting dev->power.is_suspended
   if async_error is different from zero.]

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@kernel.org
2011-06-21 23:20:20 +02:00
Alan Stern f76b168b6f PM: Rename dev_pm_info.in_suspend to is_prepared
This patch (as1473) renames the "in_suspend" field in struct
dev_pm_info to "is_prepared", in preparation for an upcoming change.
The new name is more descriptive of what the field really means.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@kernel.org
2011-06-21 23:19:50 +02:00
Ohad Ben-Cohen ab493a0f0f drivers: iommu: move to a dedicated folder
Create a dedicated folder for iommu drivers, and move the base
iommu implementation over there.

Grouping the various iommu drivers in a single location will help
finding similar problems shared by different platforms, so they
could be solved once, in the iommu framework, instead of solved
differently (or duplicated) in each driver.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2011-06-14 14:47:41 +02:00
Rafael J. Wysocki 3b3eca3116 PM / Runtime: Fix loops in pm_runtime_clk_notify()
The loops over connection ID strings in pm_runtime_clk_notify()
should actually iterate over the strings and not over the elements
of the first of them, so make them behave as appropriate.

This fixes a regression introduced by commit 600b776eb3
(OMAP1 / PM: Use generic clock manipulation routines for runtime PM).

Reported-and-tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-06-07 23:34:58 +02:00
Andrew Morton bb2b43fefa drivers/base/platform.c: don't mark platform_device_register_resndata() as __init_or_module
This reverts 737a3bb941 ("Driver core: move platform device
creation helpers to .init.text (if MODULE=n)").  That patch assumed that
platform_device_register_resndata() is only ever called from __init code
but that isn't true in the case ioctl->drm_ioctl->radeon_cp_init().

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=35192

Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reported-by: Anthony Basile <blueness@gentoo.org>
Cc: Greg KH <gregkh@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-06-07 10:01:17 -07:00
KOSAKI Motohiro fa25c503df mm: per-node vmstat: show proper vmstats
commit 2ac390370a ("writeback: add
/sys/devices/system/node/<node>/vmstat") added vmstat entry.  But
strangely it only show nr_written and nr_dirtied.

        # cat /sys/devices/system/node/node20/vmstat
        nr_written 0
        nr_dirtied 0

Of course, It's not adequate.  With this patch, the vmstat show all vm
stastics as /proc/vmstat.

        # cat /sys/devices/system/node/node0/vmstat
	nr_free_pages 899224
	nr_inactive_anon 201
	nr_active_anon 17380
	nr_inactive_file 31572
	nr_active_file 28277
	nr_unevictable 0
	nr_mlock 0
	nr_anon_pages 17321
	nr_mapped 8640
	nr_file_pages 60107
	nr_dirty 33
	nr_writeback 0
	nr_slab_reclaimable 6850
	nr_slab_unreclaimable 7604
	nr_page_table_pages 3105
	nr_kernel_stack 175
	nr_unstable 0
	nr_bounce 0
	nr_vmscan_write 0
	nr_writeback_temp 0
	nr_isolated_anon 0
	nr_isolated_file 0
	nr_shmem 260
	nr_dirtied 1050
	nr_written 938
	numa_hit 962872
	numa_miss 0
	numa_foreign 0
	numa_interleave 8617
	numa_local 962872
	numa_other 0
	nr_anon_transparent_hugepages 0

[akpm@linux-foundation.org: no externs in .c files]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michael Rubin <mrubin@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:07 -07:00
Linus Torvalds 57d19e80f4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  b43: fix comment typo reqest -> request
  Haavard Skinnemoen has left Atmel
  cris: typo in mach-fs Makefile
  Kconfig: fix copy/paste-ism for dell-wmi-aio driver
  doc: timers-howto: fix a typo ("unsgined")
  perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c
  md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course').
  treewide: fix a few typos in comments
  regulator: change debug statement be consistent with the style of the rest
  Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations"
  audit: acquire creds selectively to reduce atomic op overhead
  rtlwifi: don't touch with treewide double semicolon removal
  treewide: cleanup continuations and remove logging message whitespace
  ath9k_hw: don't touch with treewide double semicolon removal
  include/linux/leds-regulator.h: fix syntax in example code
  tty: fix typo in descripton of tty_termios_encode_baud_rate
  xtensa: remove obsolete BKL kernel option from defconfig
  m68k: fix comment typo 'occcured'
  arch:Kconfig.locks Remove unused config option.
  treewide: remove extra semicolons
  ...
2011-05-23 09:12:26 -07:00
Linus Torvalds 39ab05c8e0 Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (44 commits)
  debugfs: Silence DEBUG_STRICT_USER_COPY_CHECKS=y warning
  sysfs: remove "last sysfs file:" line from the oops messages
  drivers/base/memory.c: fix warning due to "memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION"
  memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION
  SYSFS: Fix erroneous comments for sysfs_update_group().
  driver core: remove the driver-model structures from the documentation
  driver core: Add the device driver-model structures to kerneldoc
  Translated Documentation/email-clients.txt
  RAW driver: Remove call to kobject_put().
  reboot: disable usermodehelper to prevent fs access
  efivars: prevent oops on unload when efi is not enabled
  Allow setting of number of raw devices as a module parameter
  Introduce CONFIG_GOOGLE_FIRMWARE
  driver: Google Memory Console
  driver: Google EFI SMI
  x86: Better comments for get_bios_ebda()
  x86: get_bios_ebda_length()
  misc: fix ti-st build issues
  params.c: Use new strtobool function to process boolean inputs
  debugfs: move to new strtobool
  ...

Fix up trivial conflicts in fs/debugfs/file.c due to the same patch
being applied twice, and an unrelated cleanup nearby.
2011-05-19 18:24:11 -07:00
Rafael J. Wysocki 6538df8019 PM: Introduce generic prepare and complete callbacks for subsystems
Introduce generic .prepare() and .complete() power management
callbacks, currently missing, that can be used by subsystems and
power domains and export them.  Provide NULL definitions of all
the generic system sleep callbacks for CONFIG_PM_SLEEP unset.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-17 23:26:21 +02:00
Rafael J. Wysocki 91e7c75ba9 PM: Allow drivers to allocate memory from .prepare() callbacks safely
If device drivers allocate substantial amounts of memory (above 1 MB)
in their hibernate .freeze() callbacks (or in their legacy suspend
callbcks during hibernation), the subsequent creation of hibernate
image may fail due to the lack of memory.  This is the case, because
the drivers' .freeze() callbacks are executed after the hibernate
memory preallocation has been carried out and the preallocated amount
of memory may be too small to cover the new driver allocations.
Unfortunately, the drivers' .prepare() callbacks also are executed
after the hibernate memory preallocation has completed, so they are
not suitable for allocating additional memory either.  Thus the only
way a driver can safely allocate memory during hibernation is to use
a hibernate/suspend notifier.  However, the notifiers are called
before the freezing of user space and the drivers wanting to use them
for allocating additional memory may not know how much memory needs
to be allocated at that point.

To let device drivers overcome this difficulty rework the hibernation
sequence so that the memory preallocation is carried out after the
drivers' .prepare() callbacks have been executed, so that the
.prepare() callbacks can be used for allocating additional memory
to be used by the drivers' .freeze() callbacks.  Update documentation
to match the new behavior of the code.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-17 23:26:00 +02:00
Rafael J. Wysocki c650da23d5 PM: Remove CONFIG_PM_VERBOSE
Now that we have CONFIG_DYNAMIC_DEBUG there is no need for yet
another flag causing dev_dbg() and pr_debug() statements in the
core PM code to produce output.  Moreover, CONFIG_PM_VERBOSE
causes so much output to be generated that it's not really useful
and almost no one sets it.

References: https://bugzilla.kernel.org/show_bug.cgi?id=23182
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-17 23:25:10 +02:00
Rafael J. Wysocki 290c748725 Merge branch 'power-domains' into for-linus
* power-domains:
  PM: Fix build issue in clock_ops.c for CONFIG_PM_RUNTIME unset
  PM: Revert "driver core: platform_bus: allow runtime override of dev_pm_ops"
  OMAP1 / PM: Use generic clock manipulation routines for runtime PM
  PM / Runtime: Generic clock manipulation rountines for runtime PM (v6)
  PM / Runtime: Add subsystem data field to struct dev_pm_info
  OMAP2+ / PM: move runtime PM implementation to use device power domains
  PM / Platform: Use generic runtime PM callbacks directly
  shmobile: Use power domains for platform runtime PM
  PM: Export platform bus type's default PM callbacks
  PM: Make power domain callbacks take precedence over subsystem ones
2011-05-17 23:23:46 +02:00
Rafael J. Wysocki 2d2a9163bd Merge branch 'syscore' into for-linus
* syscore:
  PM: Remove sysdev suspend, resume and shutdown operations
  PM / PowerPC: Use struct syscore_ops instead of sysdevs for PM
  PM / UNICORE32: Use struct syscore_ops instead of sysdevs for PM
  PM / AVR32: Use struct syscore_ops instead of sysdevs for PM
  PM / Blackfin: Use struct syscore_ops instead of sysdevs for PM
  ARM / Samsung: Use struct syscore_ops for "core" power management
  ARM / PXA: Use struct syscore_ops for "core" power management
  ARM / SA1100: Use struct syscore_ops for "core" power management
  ARM / Integrator: Use struct syscore_ops for core PM
  ARM / OMAP: Use struct syscore_ops for "core" power management
  ARM: Use struct syscore_ops instead of sysdevs for PM in common code
2011-05-17 23:23:40 +02:00
Eric Dumazet 13e3813656 PM / Wakeup: Remove useless synchronize_rcu() call
wakeup_source_add() adds an item into wakeup_sources list.

There is no need to call synchronize_rcu() at this point.

Its only needed in wakeup_source_remove()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-17 23:19:19 +02:00
Rafael J. Wysocki e762318baa PM / Wakeup: Fix build warning related to the "wakeup" sysfs file
The "wakeup" device sysfs file is only created if CONFIG_PM_SLEEP
is set, so put it under CONFIG_PM_SLEEP and make a build warning
related to it go away.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-17 23:19:18 +02:00
Rafael J. Wysocki a144c6a6c9 PM: Print a warning if firmware is requested when tasks are frozen
Some drivers erroneously use request_firmware() from their ->resume()
(or ->thaw(), or ->restore()) callbacks, which is not going to work
unless the firmware has been built in.  This causes system resume to
stall until the firmware-loading timeout expires, which makes users
think that the resume has failed and reboot their machines
unnecessarily.  For this reason, make _request_firmware() print a
warning and return immediately with error code if it has been called
when tasks are frozen and it's impossible to start any new usermode
helpers.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
2011-05-17 23:19:17 +02:00
Rafael J. Wysocki e1866b33b1 PM / Runtime: Rework runtime PM handling during driver removal
The driver core tries to prevent race conditions between runtime PM
and driver removal from happening by incrementing the runtime PM
usage counter of the device and executing pm_runtime_barrier() before
running the bus notifier and the ->remove() callbacks provided by the
device's subsystem or driver.  This guarantees that, if a future
runtime suspend of the device has been scheduled or a runtime resume
or idle request has been queued up right before the driver removal,
it will be canceled or waited for to complete and no other
asynchronous runtime suspend or idle requests for the device will be
put into the PM workqueue until the ->remove() callback returns.
However, it doesn't prevent resume requests from being queued up
after pm_runtime_barrier() has been called and it doesn't prevent
pm_runtime_resume() from executing the device subsystem's runtime
resume callback.  Morever, it prevents the device's subsystem or
driver from putting the device into the suspended state by calling
pm_runtime_suspend() from its ->remove() routine.  This turns out to
be a major inconvenience for some subsystems and drivers that want to
leave the devices they handle in the suspended state.

To really prevent runtime PM callbacks from racing with the bus
notifier callback in __device_release_driver(), which is necessary,
because the notifier is used by some subsystems to carry out
operations affecting the runtime PM functionality, use
pm_runtime_get_sync() instead of the combination of
pm_runtime_get_noresume() and pm_runtime_barrier().  This will resume
the device if it's in the suspended state and will prevent it from
being suspended again until pm_runtime_put_*() is called.

To allow subsystems and drivers to put devices into the suspended
state by calling pm_runtime_suspend() from their ->remove() routines,
execute pm_runtime_put_sync() after running the bus notifier in
__device_release_driver().  This will require subsystems and drivers
to make their ->remove() callbacks avoid races with runtime PM
directly, but it will allow of more flexibility in the handling of
devices during the removal of their drivers.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-17 23:19:17 +02:00
Rafael J. Wysocki 72874daa5e PM: Fix build issue in clock_ops.c for CONFIG_PM_RUNTIME unset
Fix a build issue in drivers/base/power/clock_ops.c occuring when
CONFIG_PM_RUNTIME is not set.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-16 20:17:48 +02:00
Kevin Hilman 2064af917b PM: Revert "driver core: platform_bus: allow runtime override of dev_pm_ops"
The platform_bus_set_pm_ops() operation is deprecated in favor of the
new device power domain infrastructre implemented in commit
7538e3db6e (PM: add support for device
power domains)

Signed-off-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-16 20:17:47 +02:00
Andrew Morton a236c71766 drivers/base/memory.c: fix warning due to "memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION"
drivers/base/memory.c: In function 'memory_block_change_state':
drivers/base/memory.c:281: warning: unused variable 'i'

less beer, more testing

Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-12 13:27:19 -07:00
Anton Blanchard 5409d2cd84 memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION
On ppc64 the minimum memory section for hotplug is 16MB but most
recent machines have a memory block size of 256MB. This means
memory_block_change_state does 16 separate calls to
memory_section_action.

This also means we call the notifiers 16 times and the hook
in the ehea network driver is quite costly. To offline one 256MB
region takes:

# time echo offline > /sys/devices/system/memory/memory32/state
7.9s

This patch removes the loop and calls online_pages or
remove_memory once for the entire region and in doing so makes
the logic simpler since we don't have to back out if things fail
part way through.

The same test to offline one region now takes:

# time echo online > /sys/devices/system/memory/memory32/state
0.67s

Over 11 times faster.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-11 15:19:27 -07:00
Rafael J. Wysocki 2e711c04db PM: Remove sysdev suspend, resume and shutdown operations
Since suspend, resume and shutdown operations in struct sysdev_class
and struct sysdev_driver are not used any more, remove them.  Also
drop sysdev_suspend(), sysdev_resume() and sysdev_shutdown() used
for executing those operations and modify all of their users
accordingly.  This reduces kernel code size quite a bit and reduces
its complexity.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-11 21:37:15 +02:00
Rafael J. Wysocki 85eb8c8d0b PM / Runtime: Generic clock manipulation rountines for runtime PM (v6)
Many different platforms and subsystems may want to disable device
clocks during suspend and enable them during resume which is going to
be done in a very similar way in all those cases.  For this reason,
provide generic routines for the manipulation of device clocks during
suspend and resume.

Convert the ARM shmobile platform to using the new routines.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-04-30 00:25:44 +02:00
Rafael J. Wysocki 8b313a38ec PM / Platform: Use generic runtime PM callbacks directly
Once shmobile platforms have been converted to using power domains
for overriding the platform bus type's PM callbacks, it isn't
necessary to use the __weakly defined wrappers around the generinc
runtime PM callbacks in the platform bus type any more.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-04-29 00:36:32 +02:00
Rafael J. Wysocki 69c9dd1ecf PM: Export platform bus type's default PM callbacks
Export the default PM callbacks defined for the platform bus type so
that they can be used by power domains for suspending and resuming
platform devices in the future.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-04-29 00:36:05 +02:00
Rafael J. Wysocki 4d27e9dcff PM: Make power domain callbacks take precedence over subsystem ones
Change the PM core's behavior related to power domains in such a way
that, if a power domain is defined for a given device, its callbacks
will be executed instead of and not in addition to the device
subsystem's PM callbacks.

The idea behind the initial implementation of power domains handling
by the PM core was that power domain callbacks would be executed in
addition to subsystem callbacks, so that it would be possible to
extend the subsystem callbacks by using power domains.  It turns out,
however, that this wouldn't be really convenient in some important
situations.

For example, there are systems in which power can only be removed
from entire power domains.  On those systems it is not desirable to
execute device drivers' PM callbacks until it is known that power is
going to be removed from the devices in question, which means that
they should be executed by power domain callbacks rather then by
subsystem (e.g. bus type) PM callbacks, because subsystems generally
have no information about what devices belong to which power domain.
Thus, for instance, if the bus type in question is the platform bus
type, its PM callbacks generally should not be called in addition to
power domain callbacks, because they run device drivers' callbacks
unconditionally if defined.

While in principle the default subsystem PM callbacks, or a subset of
them, may be replaced with different functions, it doesn't seem
correct to do so, because that would change the subsystem's behavior
with respect to all devices in the system, regardless of whether or
not they belong to any power domains.  Thus, the only remaining
option is to make power domain callbacks take precedence over
subsystem callbacks.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Kevin Hilman <khilman@ti.com>
2011-04-29 00:35:50 +02:00
Rafael J. Wysocki 22110faf8c PM / Wakeup: Fix initialization of wakeup-related device sysfs files
It turns out that some PCI devices are only found to be
wakeup-capable during registration, in which case, when
device_set_wakeup_capable() is called, device_is_registered() already
returns 'true' for the given device, but dpm_sysfs_add() hasn't been
called for it yet.  This leads to situations in which the device's
power.can_wakeup flag is not set as requested because of failing
wakeup_sysfs_add() and its wakeup-related sysfs files are not
created, although they should be present.  This is a post-2.6.38
regression introduced by commit cb8f51bdad
(PM: Do not create wakeup sysfs files for devices that cannot wake
up).

To work around this problem initialize the device's power.entry
field to an empty list head and make device_set_wakeup_capable()
check if it is still empty before attempting to add the devices
wakeup-related sysfs files with wakeup_sysfs_add().  Namely, if
power.entry is still empty at this point, device_pm_add() hasn't been
called yet for the device and its wakeup-related files will be
created later, so device_set_wakeup_capable() doesn't have to create
them.

Reported-and-tested-by: Tino Keitel <tino.keitel@tikei.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-26 11:33:09 +02:00
Jiri Kosina 07f9479a40 Merge branch 'master' into for-next
Fast-forwarded to current state of Linus' tree as there are patches to be
applied for files that didn't exist on the old branch.
2011-04-26 10:22:59 +02:00
Wanlong Gao 8572394353 drivers:base:fix the coding format of memory.c
Fix the line longer than 80 of memory_uevent function .

Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-25 15:52:40 -07:00
Uwe Kleine-König c870508240 driver core: let dev_set_drvdata return int instead of void as it can fail
Before commit

	b402843 (Driver core: move dev_get/set_drvdata to drivers/base/dd.c)

calling dev_set_drvdata with dev=NULL was an unchecked error. After some
discussion about what to return in this case removing the check (and so
producing a null pointer exception) seems fine.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-22 17:09:13 -07:00
Uwe Kleine-König 4a03d6f7c8 driver core/platform_device_add_resources: free resource before overwriting
Reviewed-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-22 17:09:13 -07:00
Uwe Kleine-König cea896238f driver core/platform_device_add_resources: set resource to NULL if !res
This makes the res = NULL case more consistant to the res != NULL case
as now both overwrite pdev->resource.

Reviewed-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-22 17:09:13 -07:00
Uwe Kleine-König 251e031d13 driver core/platform_device_add_data: free platform data before overwriting
Reviewed-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-22 17:09:12 -07:00
Uwe Kleine-König 27a33f9e8f driver core/platform_device_add_data: set platform_data to NULL if !data
This makes the data = NULL case more consistent to the data != NULL case.
The functional change is that now

	platform_device_add_data(somepdev, NULL, somesize)

sets pdev->dev.platform_data to NULL instead of not touching it.

Reviewed-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-22 17:09:11 -07:00
Karthigan Srinivasan 7f100d1566 drivers/base/core.c: Fixed brace coding style issue.
Fixed brace coding style issue.

Signed-off-by: Karthigan Srinivasan <karthigan.srinivasan@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-22 17:06:30 -07:00
Sebastian Ott 8497d6a21c driver-core: fix race between device_register and driver_register
When a device is registered to a bus it will be a) added to the list
of devices of the bus and b) bind to a driver (if one matches). As a
result of a driver being registered at this bus between a) and b) this
device could already be bound to a driver. This leads to a warning
and incorrect refcounting.
To fix this add a check to device_attach to identify an already bound
device.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-22 17:06:29 -07:00
Stephen Hemminger aed65af1cc drivers: make device_type const
The device_type structure does not contain data that changes
during usage and should be const. This allows devices to declare
the struct const.

I have patches to change all the subsystems, but need the infra
structure change first.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:45:51 -07:00
Rafael J. Wysocki 19234c0819 PM: Add missing syscore_suspend() and syscore_resume() calls
Device suspend/resume infrastructure is used not only by the suspend
and hibernate code in kernel/power, but also by APM, Xen and the
kexec jump feature.  However, commit 40dc166cb5
(PM / Core: Introduce struct syscore_ops for core subsystems PM)
failed to add syscore_suspend() and syscore_resume() calls to that
code, which generally leads to breakage when the features in question
are used.

To fix this problem, add the missing syscore_suspend() and
syscore_resume() calls to arch/x86/kernel/apm_32.c, kernel/kexec.c
and drivers/xen/manage.c.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2011-04-20 00:36:11 +02:00
Linus Torvalds aaa119a3d4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  fix XEN_SAVE_RESTORE Kconfig dependencies
  PM / Hibernate: Introduce CONFIG_HIBERNATE_CALLBACKS
2011-04-12 17:18:05 -07:00
Samuel Ortiz e710d7d5a9 mfd: Fetch cell pointer from platform_device->mfd_cell
In order for MFD drivers to fetch their cell pointer but also their
platform data one, an mfd cell pointer is added to the platform_device
structure.
That allows all MFD sub devices drivers to be MFD agnostic, unless
they really need to access their MFD cell data. Most of them don't,
especially the ones for IPs used by both MFD and non MFD SoCs.

Cc: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Greg KH <gregkh@suse.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2011-04-12 11:13:00 +02:00
Rafael J. Wysocki 1f112cee07 PM / Hibernate: Introduce CONFIG_HIBERNATE_CALLBACKS
Xen save/restore is going to use hibernate device callbacks for
quiescing devices and putting them back to normal operations and it
would need to select CONFIG_HIBERNATION for this purpose.  However,
that also would cause the hibernate interfaces for user space to be
enabled, which might confuse user space, because the Xen kernels
don't support hibernation.  Moreover, it would be wasteful, as it
would make the Xen kernels include a substantial amount of code that
they would never use.

To address this issue introduce new power management Kconfig option
CONFIG_HIBERNATE_CALLBACKS, such that it will only select the code
that is necessary for the hibernate device callbacks to work and make
CONFIG_HIBERNATION select it.  Then, Xen save/restore will be able to
select CONFIG_HIBERNATE_CALLBACKS without dragging the entire
hibernate code along with it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
2011-04-11 22:54:42 +02:00
Nikanth Karthikesan 9f0af69b2d sysfs-memory: fix uninitialized variable warning and clean-up code.
sysfs-memory: Fix uninitialized variable warning and clean-up code.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-04-10 17:01:05 +02:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Rafael J. Wysocki d47d81c0e9 Introduce ARCH_NO_SYSDEV_OPS config option (v2)
Introduce Kconfig option allowing architectures where sysdev
operations used during system suspend, resume and shutdown have been
completely replaced with struct sycore_ops operations to avoid
building sysdev code that will never be used.

Make callbacks in struct sys_device and struct sysdev_driver depend
on ARCH_NO_SYSDEV_OPS to allows us to verify if all of the references
have been actually removed from the code the given architecture
depends on.

Make x86 select ARCH_NO_SYSDEV_OPS.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-23 22:16:41 +01:00
Linus Torvalds a5e6b135bd Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (50 commits)
  printk: do not mangle valid userspace syslog prefixes
  efivars: Add Documentation
  efivars: Expose efivars functionality to external drivers.
  efivars: Parameterize operations.
  efivars: Split out variable registration
  efivars: parameterize efivars
  efivars: Make efivars bin_attributes dynamic
  efivars: move efivars globals into struct efivars
  drivers:misc: ti-st: fix debugging code
  kref: Fix typo in kref documentation
  UIO: add PRUSS UIO driver support
  Fix spelling mistakes in Documentation/zh_CN/SubmittingPatches
  firmware: Fix unaligned memory accesses in dmi-sysfs
  firmware: Add documentation for /sys/firmware/dmi
  firmware: Expose DMI type 15 System Event Log
  firmware: Break out system_event_log in dmi-sysfs
  firmware: Basic dmi-sysfs support
  firmware: Add DMI entry types to the headers
  Driver core: convert platform_{get,set}_drvdata to static inline functions
  Translate linux-2.6/Documentation/magic-number.txt into Chinese
  ...
2011-03-16 15:05:40 -07:00
Rafael J. Wysocki 40dc166cb5 PM / Core: Introduce struct syscore_ops for core subsystems PM
Some subsystems need to carry out suspend/resume and shutdown
operations with one CPU on-line and interrupts disabled.  The only
way to register such operations is to define a sysdev class and
a sysdev specifically for this purpose which is cumbersome and
inefficient.  Moreover, the arguments taken by sysdev suspend,
resume and shutdown callbacks are practically never necessary.

For this reason, introduce a simpler interface allowing subsystems
to register operations to be executed very late during system suspend
and shutdown and very early during resume in the form of
strcut syscore_ops objects.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-15 00:43:46 +01:00
Nishanth Menon 7ae4961878 PM / OPP: opp_find_freq_exact() documentation fix
opp_find_freq_exact() documentation has is_available instead
of available. This also fixes warning with the kernel-doc:
scripts/kernel-doc drivers/base/power/opp.c >/dev/null
Warning(drivers/base/power/opp.c:246): No description found for parameter 'available'
Warning(drivers/base/power/opp.c:246): Excess function parameter 'is_available' description in 'opp_find_freq_exact'

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:17 +01:00
Rafael J. Wysocki 9659cc0678 PM: Make system-wide PM and runtime PM treat subsystems consistently
The code handling system-wide power transitions (eg. suspend-to-RAM)
can in theory execute callbacks provided by the device's bus type,
device type and class in each phase of the power transition.  In
turn, the runtime PM core code only calls one of those callbacks at
a time, preferring bus type callbacks to device type or class
callbacks and device type callbacks to class callbacks.

It seems reasonable to make them both behave in the same way in that
respect.  Moreover, even though a device may belong to two subsystems
(eg. bus type and device class) simultaneously, in practice power
management callbacks for system-wide power transitions are always
provided by only one of them (ie. if the bus type callbacks are
defined, the device class ones are not and vice versa).  Thus it is
possible to modify the code handling system-wide power transitions
so that it follows the core runtime PM code (ie. treats the
subsystem callbacks as mutually exclusive).

On the other hand, the core runtime PM code will choose to execute,
for example, a runtime suspend callback provided by the device type
even if the bus type's struct dev_pm_ops object exists, but the
runtime_suspend pointer in it happens to be NULL.  This is confusing,
because it may lead to the execution of callbacks from different
subsystems during different operations (eg. the bus type suspend
callback may be executed during runtime suspend of the device, while
the device type callback will be executed during system suspend).

Make all of the power management code treat subsystem callbacks in
a consistent way, such that:
(1) If the device's type is defined (eg. dev->type is not NULL)
    and its pm pointer is not NULL, the callbacks from dev->type->pm
    will be used.
(2) If dev->type is NULL or dev->type->pm is NULL, but the device's
    class is defined (eg. dev->class is not NULL) and its pm pointer
    is not NULL, the callbacks from dev->class->pm will be used.
(3) If dev->type is NULL or dev->type->pm is NULL and dev->class is
    NULL or dev->class->pm is NULL, the callbacks from dev->bus->pm
    will be used provided that both dev->bus and dev->bus->pm are
    not NULL.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
Reasoning-sounds-sane-to: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-15 00:43:17 +01:00
Rafael J. Wysocki 7538e3db6e PM: Add support for device power domains
The platform bus type is often used to handle Systems-on-a-Chip (SoC)
where all devices are represented by objects of type struct
platform_device.  In those cases the same "platform" device driver
may be used with multiple different system configurations, but the
actions needed to put the devices it handles into a low-power state
and back into the full-power state may depend on the design of the
given SoC.  The driver, however, cannot possibly include all the
information necessary for the power management of its device on all
the systems it is used with.  Moreover, the device hierarchy in its
current form also is not suitable for representing this kind of
information.

The patch below attempts to address this problem by introducing
objects of type struct dev_power_domain that can be used for
representing power domains within a SoC.  Every struct
dev_power_domain object provides a sets of device power
management callbacks that can be used to perform what's needed for
device power management in addition to the operations carried out by
the device's driver and subsystem.

Namely, if a struct dev_power_domain object is pointed to by the
pwr_domain field in a struct device, the callbacks provided by its
ops member will be executed in addition to the corresponding
callbacks provided by the device's subsystem and driver during all
power transitions.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-and-acked-by: Kevin Hilman <khilman@ti.com>
2011-03-15 00:43:16 +01:00
Rafael J. Wysocki e866500247 PM: Allow pm_runtime_suspend() to succeed during system suspend
The dpm_prepare() function increments the runtime PM reference
counters of all devices to prevent pm_runtime_suspend() from
executing subsystem-level callbacks.  However, this was supposed to
guard against a specific race condition that cannot happen, because
the power management workqueue is freezable, so pm_runtime_suspend()
can only be called synchronously during system suspend and we can
rely on subsystems and device drivers to avoid doing that
unnecessarily.

Make dpm_prepare() drop the runtime PM reference to each device
after making sure that runtime resume is not pending for it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
2011-03-15 00:43:16 +01:00
Rafael J. Wysocki aa33860158 PM: Remove CONFIG_PM_OPS
After redefining CONFIG_PM to depend on (CONFIG_PM_SLEEP ||
CONFIG_PM_RUNTIME) the CONFIG_PM_OPS option is redundant and can be
replaced with CONFIG_PM.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:15 +01:00
Rafael J. Wysocki cb8f51bdad PM: Do not create wakeup sysfs files for devices that cannot wake up
Currently, wakeup sysfs attributes are created for all devices,
regardless of whether or not they are wakeup-capable.  This is
excessive and complicates wakeup device identification from user
space (i.e. to identify wakeup-capable devices user space has to read
/sys/devices/.../power/wakeup for all devices and see if they are not
empty).

Fix this issue by avoiding to create wakeup sysfs files for devices
that cannot wake up the system from sleep states (i.e. whose
power.can_wakeup flags are unset during registration) and modify
device_set_wakeup_capable() so that it adds (or removes) the relevant
sysfs attributes if a device's wakeup capability status is changed.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:14 +01:00
Mandeep Singh Baines 0295a34d61 PM: Use appropriate printk() priority level in trace.c
printk()s without a priority level default to KERN_WARNING. To reduce
noise at KERN_WARNING, this patch sets the priority level appriopriately
for unleveled printks()s. This should be useful to folks that look at
dmesg warnings closely.

Changed these messages to pr_info().

Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:14 +01:00
Rafael J. Wysocki 790c7885a4 PM / Wakeup: Don't update events_check_enabled in pm_get_wakeup_count()
Since pm_save_wakeup_count() has just been changed to clear
events_check_enabled unconditionally before checking if there are
any new wakeup events registered since the last read from
/sys/power/wakeup_count, the detection of wakeup events during
suspend may be disabled, after it's been enabled, by writing a
"wrong" value back to /sys/power/wakeup_count.  For this reason,
it is not necessary to update events_check_enabled in
pm_get_wakeup_count() any more.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:14 +01:00
Rafael J. Wysocki 378eef99ad PM / Wakeup: Make pm_save_wakeup_count() work as documented
According to Documentation/ABI/testing/sysfs-power, the
/sys/power/wakeup_count interface should only make the kernel react
to wakeup events during suspend if the last write to it has been
successful.  However, if /sys/power/wakeup_count is written to two
times in a row, where the first write is successful and the second
is not, the kernel will still react to wakeup events during suspend
due to a bug in pm_save_wakeup_count().

Fix the bug by making pm_save_wakeup_count() clear
events_check_enabled unconditionally before checking if there are
any new wakeup events registered since the previous read from
/sys/power/wakeup_count.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:13 +01:00
Rafael J. Wysocki 023d377914 PM / Wakeup: Combine atomic counters to avoid reordering issues
The memory barrier in wakeup_source_deactivate() is supposed to
prevent the callers of pm_wakeup_pending() and pm_get_wakeup_count()
from seeing the new value of events_in_progress (0, in particular)
and the old value of event_count at the same time.  However, if
wakeup_source_deactivate() is executed by CPU0 and, for instance,
pm_wakeup_pending() is executed by CPU1, where both processors can
reorder operations, the memory barrier in wakeup_source_deactivate()
doesn't affect CPU1 which can reorder reads.  In that case CPU1 may
very well decide to fetch event_count before it's modified and
events_in_progress after it's been updated, so pm_wakeup_pending()
may fail to detect a wakeup event.  This issue can be addressed by
using a single atomic variable to store both events_in_progress
and event_count, so that they can be updated together in a single
atomic operation.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:13 +01:00
Ferenc Wagner 481e20799b driver core: Replace the dangerous to_root_device macro with an inline function
The original macro worked only when applied to variables named 'dev'.
While this could have been fixed by simply renaming the macro argument,
a more type-safe replacement by an inline function is preferred.

Signed-off-by: Ferenc Wagner <wferi@niif.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 16:36:40 -08:00
Nathan Fontenot 6add7cd618 memory hotplug: sysfs probe routine should add all memory sections
As a follow-on to the recent patches I submitted that allowed for a sysfs
memory block to span multiple memory sections, we should also update the
probe routine to online all of the memory sections in a memory block.  Without
this patch the current code will only add a single memory section.  I think
the probe routine should add all of the memory sections in the specified memory
block so that its behavior is in line with memory hotplug actions through
the sysfs interfaces.

This patch applies on top of the previous sysfs memory updates to allow
a sysfs directory o span multiple memory sections.

https://lkml.org/lkml/2011/1/20/245

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 16:08:58 -08:00
Nathan Fontenot d33601644c memory hotplug: Update phys_index to [start|end]_section_nr
Update the 'phys_index' property of a the memory_block struct to be
called start_section_nr, and add a end_section_nr property.  The
data tracked here is the same but the updated naming is more in line
with what is stored here, namely the first and last section number
that the memory block spans.

The names presented to userspace remain the same, phys_index for
start_section_nr and end_phys_index for end_section_nr, to avoid breaking
anything in userspace.

This also updates the node sysfs code to be aware of the new capability for
a memory block to contain multiple memory sections and be aware of the memory
block structure name changes (start_section_nr).  This requires an additional
parameter to unregister_mem_sect_under_nodes so that we know which memory
section of the memory block to unregister.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Reviewed-by: Robin Holt <holt@sgi.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 16:08:57 -08:00
Nathan Fontenot 0c2c99b1b8 memory hotplug: Allow memory blocks to span multiple memory sections
Update the memory sysfs code such that each sysfs memory directory is now
considered a memory block that can span multiple memory sections per
memory block.  The default size of each memory block is SECTION_SIZE_BITS
to maintain the current behavior of having a single memory section per
memory block (i.e. one sysfs directory per memory section).

For architectures that want to have memory blocks span multiple
memory sections they need only define their own memory_block_size_bytes()
routine.

Update the memory hotplug documentation to reflect the new behaviors of
memory blocks reflected in sysfs.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Reviewed-by: Robin Holt <holt@sgi.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 16:08:57 -08:00
Borislav Petkov f4203e3032 sysdev: Do not register with sysdev when erroring on add
When encountering an error while executing the driver's ->add method, we
should cancel registration and unwind what we've regged so far. The low
level ->add methods do return proper error codes but those aren't looked
at in sysdev_driver_register(). Fix that by sharing the unregistering
code.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 15:41:03 -08:00
Borislav Petkov 345279bc10 sysdev: Fixup warning message
Use gcc's __func__ instead of the function name.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 15:39:17 -08:00
Bob Liu 072fc8f0a8 firmware_classs: change val uevent's type to bool
Some place in firmware_class.c using "int uevent" define, but others use "bool
uevent".
This patch replace all int uevent define to bool.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 15:39:17 -08:00
Timur Tabi a5462516aa driver-core: document restrictions on device_rename()
Add text, courtesy of Kay Sievers, that provides some background on
device_rename() and why it shouldn't be used.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 15:10:18 -08:00
Alan Stern c3810c8878 PM / Runtime: Don't enable interrupts while running in_interrupt
This patch (as1445) fixes a bug in the runtime PM core left over from
the addition of the no_callbacks flag.  If this flag is set then it is
possible for rpm_suspend() to be called in_interrupt, so when
releasing spinlocks it's important not to re-enable interrupts.

To avoid an unnecessary save-and-restore of the interrupt flag, the
patch also inlines a pm_request_idle() call.

This fixes Bugzilla #27482.

(The offending code was added in 2.6.37, so it's not necessary to apply
this to any earlier stable kernels.)

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: tim blechmann <tim@klingt.org>
CC: <stable@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-01-25 20:50:07 +01:00
David Rientjes 6a108a14fa kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT
The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
only small devices.

This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
references to the option throughout the kernel.  A new CONFIG_EMBEDDED
option is added that automatically selects CONFIG_EXPERT when enabled and
can be used in the future to isolate options that should only be
considered for embedded systems (RISC architectures, SLOB, etc).

Calling the option "EXPERT" more accurately represents its intention: only
expert users who understand the impact of the configuration changes they
are making should enable it.

Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: David Woodhouse <david.woodhouse@intel.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Greg KH <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-20 17:02:05 -08:00
David Rientjes 05b258e997 thp: transparent hugepage sysfs meminfo
Add hugepage statistics to per-node sysfs meminfo

Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:46 -08:00
Linus Torvalds 008d23e485 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
  Documentation/trace/events.txt: Remove obsolete sched_signal_send.
  writeback: fix global_dirty_limits comment runtime -> real-time
  ppc: fix comment typo singal -> signal
  drivers: fix comment typo diable -> disable.
  m68k: fix comment typo diable -> disable.
  wireless: comment typo fix diable -> disable.
  media: comment typo fix diable -> disable.
  remove doc for obsolete dynamic-printk kernel-parameter
  remove extraneous 'is' from Documentation/iostats.txt
  Fix spelling milisec -> ms in snd_ps3 module parameter description
  Fix spelling mistakes in comments
  Revert conflicting V4L changes
  i7core_edac: fix typos in comments
  mm/rmap.c: fix comment
  sound, ca0106: Fix assignment to 'channel'.
  hrtimer: fix a typo in comment
  init/Kconfig: fix typo
  anon_inodes: fix wrong function name in comment
  fix comment typos concerning "consistent"
  poll: fix a typo in comment
  ...

Fix up trivial conflicts in:
 - drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c)
 - fs/ext4/ext4.h

Also fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.
2011-01-13 10:05:56 -08:00
Linus Torvalds e54be894ea Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  driver core: Document that device_rename() is only for networking
  sysfs: remove useless test from sysfs_merge_group
  driver-core: merge private parts of class and bus
  driver core: fix whitespace in class_attr_string
2011-01-10 16:10:33 -08:00
Linus Torvalds facc7a96d4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (34 commits)
  HID: roccat: Update sysfs attribute doc
  HID: roccat: don't use #pragma pack
  HID: roccat: Add support for Roccat Kone[+] v2
  HID: roccat: reduce number of functions in kone and pyra drivers
  HID: roccat: declare meaning of pack pragma usage in driver headers
  HID: roccat: use class for char device for sysfs attribute creation
  sysfs: Introducing binary attributes for struct class
  HID: hidraw: add compatibility ioctl() for 32-bit applications.
  HID: hid-picolcd: Fix memory leak in picolcd_debug_out_report()
  HID: picolcd: fix misuse of logical operation in place of bitop
  HID: usbhid: base runtime PM on modern API
  HID: replace offsets values with their corresponding BTN_* defines
  HID: hid-mosart: support suspend/resume
  HID: hid-mosart: ignore buttons report
  HID: hid-picolcd: don't use flush_scheduled_work()
  HID: simplify an index check in hid_lookup_collection
  HID: Hoist assigns from ifs
  HID: Remove superfluous __inline__
  HID: Use vzalloc for vmalloc/memset(,0...)
  HID: Add and use hid_<level>: dev_<level> equivalents
  ...
2011-01-10 08:15:37 -08:00
Stefan Achatz c97415a725 sysfs: Introducing binary attributes for struct class
Added dev_bin_attrs to struct class similar to existing dev_attrs.

Signed-off-by: Stefan Achatz <erazor_de@users.sourceforge.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-01-08 01:09:21 +01:00
Rafael J. Wysocki 4b31db8a16 PM / Runtime: Generic resume shouldn't set RPM_ACTIVE unconditionally
The __pm_generic_resume() function changes the given device's runtime
PM status to RPM_ACTIVE if its driver's callback returns 0, but it
only should do that if the rumtime PM is enabled for the device.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24 15:04:06 +01:00
Rafael J. Wysocki 5c1a07ab3e PM: Use dev_name() in core device suspend and resume routines
Use dev_name() wherever applicable in drivers/base/power/main.c.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24 15:03:34 +01:00
Rafael J. Wysocki b64959e615 PM: Permit registration of parentless devices during system suspend
The registration of a new parentless device during system suspend
will not lead to any complications affecting the PM core (the device
will be effectively seen after the subsequent resume has completed),
so remove the code used for detection of such events.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24 15:02:44 +01:00
Rafael J. Wysocki b8c76f6aed PM: Replace the device power.status field with a bit field
The device power.status field is too complicated for its purpose
(storing the information about whether or not the device is in the
"active" state from the PM core's point of view), so replace it with
a bit field and modify all of its users accordingly.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24 15:02:44 +01:00
Rafael J. Wysocki 5b219a51fd PM: Remove redundant checks from core device resume routines
Since a separate list of devices is used to link devices that have
completed each stage of suspend (or resume), it is not necessary to
check dev->power.status in the core device resume routines any more.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24 15:02:43 +01:00
Rafael J. Wysocki 8a43a9ab7b PM: Use a different list of devices for each stage of device suspend
Instead of keeping all devices in the same list during system suspend
and resume, regardless of what suspend-resume callbacks have been
executed for them already, use separate lists of devices that have
had their ->prepare(), ->suspend() and ->suspend_noirq() callbacks
executed.  This will allow us to simplify the core device suspend and
resume routines.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24 15:02:43 +01:00
Rafael J. Wysocki 2cbb3ce1ad PM: Avoid compiler warning in pm_noirq_op()
The compiler complains that calltime may be uninitialized in
pm_noirq_op(), so add extra initialization for that variable to
avoid the warning.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24 15:02:42 +01:00
Rafael J. Wysocki d83f905e12 PM: Use pm_wakeup_pending() in __device_suspend()
Before starting to suspend a device in __device_suspend() check if
there's a request to abort the power transition and return -EBUSY
in that case.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24 15:02:42 +01:00
Rafael J. Wysocki a2867e08c8 PM / Wakeup: Replace pm_check_wakeup_events() with pm_wakeup_pending()
To avoid confusion with the meaning and return value of
pm_check_wakeup_events() replace it with pm_wakeup_pending() that
will work the other way around (ie. return true when system-wide
power transition should be aborted).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24 15:02:42 +01:00
Rafael J. Wysocki 1e75227ef0 PM: Prevent dpm_prepare() from returning errors unnecessarily
Currently dpm_prepare() returns error code if it finds that a device
being suspended has a pending runtime resume request.  However, it
should not do that if the checking for wakeup events is not enabled.
On the other hand, if the checking for wakeup events is enabled, it
can return error when a wakeup event is detected, regardless of its
source.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24 15:02:41 +01:00
Alan Stern c7b61de5b7 PM / Runtime: Add synchronous runtime interface for interrupt handlers (v3)
This patch (as1431c) makes the synchronous runtime-PM interface
suitable for use in interrupt handlers.  Subsystems can call the new
pm_runtime_irq_safe() function to tell the PM core that a device's
runtime_suspend and runtime_resume callbacks should be invoked with
interrupts disabled and the spinlock held.  This permits the
pm_runtime_get_sync() and the new pm_runtime_put_sync_suspend()
routines to be called from within interrupt handlers.

When a device is declared irq-safe in this way, the PM core increments
the parent's usage count, so the parent will never be runtime
suspended.  This prevents difficult situations in which an irq-safe
device can't resume because it is forced to wait for its non-irq-safe
parent.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24 15:02:41 +01:00