27 Oct, 2010
1 commit
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For NUMA node systems it is important to have visibility in memory
characteristics. Two of the /proc/vmstat values "nr_written" and
"nr_dirtied" are added here.# cat /sys/devices/system/node/node20/vmstat
nr_written 0
nr_dirtied 0Signed-off-by: Michael Rubin
Reviewed-by: Wu Fengguang
Cc: Dave Chinner
Cc: Jens Axboe
Cc: KOSAKI Motohiro
Cc: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Oct, 2010
2 commits
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* 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6:
mtd/m25p80: add support to parse the partitions by OF node
of/irq: of_irq.c needs to include linux/irq.h
of/mips: Cleanup some include directives/files.
of/mips: Add device tree support to MIPS
of/flattree: Eliminate need to provide early_init_dt_scan_chosen_arch
of/device: Rework to use common platform_device_alloc() for allocating devices
of/xsysace: Fix OF probing on little-endian systems
of: use __be32 types for big-endian device tree data
of/irq: remove references to NO_IRQ in drivers/of/platform.c
of/promtree: add package-to-path support to pdt
of/promtree: add of_pdt namespace to pdt code
of/promtree: no longer call prom_ functions directly; use an ops structure
of/promtree: make drivers/of/pdt.c no longer sparc-only
sparc: break out some PROM device-tree building code out into drivers/of
of/sparc: convert various prom_* functions to use phandle
sparc: stop exporting openprom.h header
powerpc, of_serial: Endianness issues setting up the serial ports
of: MTD: Fix OF probing on little-endian systems
of: GPIO: Fix OF probing on little-endian systems -
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
Update broken web addresses in arch directory.
Update broken web addresses in the kernel.
Revert "drivers/usb: Remove unnecessary return's from void functions" for musb gadget
Revert "Fix typo: configuation => configuration" partially
ida: document IDA_BITMAP_LONGS calculation
ext2: fix a typo on comment in ext2/inode.c
drivers/scsi: Remove unnecessary casts of private_data
drivers/s390: Remove unnecessary casts of private_data
net/sunrpc/rpc_pipe.c: Remove unnecessary casts of private_data
drivers/infiniband: Remove unnecessary casts of private_data
drivers/gpu/drm: Remove unnecessary casts of private_data
kernel/pm_qos_params.c: Remove unnecessary casts of private_data
fs/ecryptfs: Remove unnecessary casts of private_data
fs/seq_file.c: Remove unnecessary casts of private_data
arm: uengine.c: remove C99 comments
arm: scoop.c: remove C99 comments
Fix typo configue => configure in comments
Fix typo: configuation => configuration
Fix typo interrest[ing|ed] => interest[ing|ed]
Fix various typos of valid in comments
...Fix up trivial conflicts in:
drivers/char/ipmi/ipmi_si_intf.c
drivers/usb/gadget/rndis.c
net/irda/irnet/irnet_ppp.c
23 Oct, 2010
16 commits
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* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (31 commits)
driver core: Display error codes when class suspend fails
Driver core: Add section count to memory_block struct
Driver core: Add mutex for adding/removing memory blocks
Driver core: Move find_memory_block routine
hpilo: Despecificate driver from iLO generation
driver core: Convert link_mem_sections to use find_memory_block_hinted.
driver core: Introduce find_memory_block_hinted which utilizes kset_find_obj_hinted.
kobject: Introduce kset_find_obj_hinted.
driver core: fix build for CONFIG_BLOCK not enabled
driver-core: base: change to new flag variable
sysfs: only access bin file vm_ops with the active lock
sysfs: Fail bin file mmap if vma close is implemented.
FW_LOADER: fix kconfig dependency warning on HOTPLUG
uio: Statically allocate uio_class and use class .dev_attrs.
uio: Support 2^MINOR_BITS minors
uio: Cleanup irq handling.
uio: Don't clear driver data
uio: Fix lack of locking in init_uio_class
SYSFS: Allow boot time switching between deprecated and modern sysfs layout
driver core: remove CONFIG_SYSFS_DEPRECATED_V2 but keep it for block devices
... -
Aid diagnostics by printing the error code from failed suspends, which
doesn't otherwise seem to get displayed.Signed-off-by: Mark Brown
Signed-off-by: Greg Kroah-Hartman -
Add a section count property to the memory_block struct to track the number
of memory sections that have been added/removed from a memory block. This
allows us to know when the last memory section of a memory block has been
removed so we can remove the memory block.Signed-off-by: Nathan Fontenot
Reviewed-by: Robin Holt
Reviewed-by: KAMEZAWA Hiroyuki
Signed-off-by: Greg Kroah-Hartman -
Add a new mutex for use in adding and removing of memory blocks. This
is needed to avoid any race conditions in which the same memory block could
be added and removed at the same time.Signed-off-by: Nathan Fontenot
Reviewed-by: Robin Holt
Reviewed-By: KAMEZAWA Hiroyuki
Signed-off-by: Greg Kroah-Hartman -
Move the find_memory_block() routine up to avoid needing a forward
declaration in subsequent patches.Signed-off-by: Nathan Fontenot
Reviewed-by: Robin Holt
Reviewed-By: KAMEZAWA Hiroyuki
Signed-off-by: Greg Kroah-Hartman -
Modify link_mem_sections() to pass in the previous mem_block as a hint to
locating the next mem_block. Since they are typically added in order this
results in a massive saving in time during boot of a very large system.
For example, on a 16TB x86_64 machine, it reduced the total time spent
linking all node's memory sections from 1 hour, 27 minutes to 46 seconds.Signed-off-by: Robin Holt
To: Gary Hade
To: Badari Pulavarty
To: Ingo Molnar
Reviewed-by: KAMEZAWA Hiroyuki
Signed-off-by: Greg Kroah-Hartman -
Introduce a find_memory_block_hinted() which utilizes the
recently added kset_find_obj_hinted().Signed-off-by: Robin Holt
To: Dave Hansen
To: Matt Tolentino
Reviewed-by: KAMEZAWA Hiroyuki
Signed-off-by: Greg Kroah-Hartman -
Fix build errors when CONFIG_BLOCK is not enabled:
drivers/base/core.c: In function 'get_device_parent':
drivers/base/core.c:634: error: 'block_class' undeclared (first use in this function)
drivers/base/core.c: In function 'device_add_class_symlinks':
drivers/base/core.c:723: error: 'block_class' undeclared (first use in this function)
drivers/base/core.c: In function 'device_remove_class_symlinks':
drivers/base/core.c:751: error: 'block_class' undeclared (first use in this function)Signed-off-by: Randy Dunlap
Signed-off-by: Greg Kroah-Hartman -
Replace EXTRA_CFLAGS with ccflags-y.
Signed-off-by: matt mooney
Acked-by: WANG Cong
Signed-off-by: Greg Kroah-Hartman -
Fix kconfig dependency warning for FW_LOADER.
Lots of drivers select FW_LOADER without bothering to depend on
HOTPLUG and/or without selecting HOTPLUG. A kernel builds fine
when FW_LOADER is enabled, whether HOTPLUG is enabled or not, and
a kernel config file (make oldconfig) is not changed by this patch.
(Yes, drivers/base/firmware_class.c uses interfaces from linux/kobject.h,
which does have some CONFIG_HOTPLUG dependencies, but this patch does
not change that.)warning: (MICROCODE || MICROCODE_INTEL && MICROCODE || MICROCODE_AMD && MICROCODE || PCMCIA_LOAD_CIS && PCCARD && PCMCIA && EXPERIMENTAL || USB_IRDA && NET && IRDA && USB || BT_HCIBCM203X && NET && BT && USB || BT_HCIBFUSB && NET && BT && USB || BT_HCIBT3C && NET && BT && PCMCIA || BT_MRVL_SDIO && NET
...
!STAGING_EXCLUDE_BUILD && USB && (X86 || ARM) && WLAN || DRM_NOUVEAU && STAGING && !STAGING_EXCLUDE_BUILD && DRM && PCI || TI_ST && STAGING && !STAGING_EXCLUDE_BUILD && RFKILL || DELL_RBU && X86) selects FW_LOADER which has unmet direct dependencies (HOTPLUG)
(5200 byte line reduced a lot)Signed-off-by: Randy Dunlap
Signed-off-by: Greg Kroah-Hartman -
I have some systems which need legacy sysfs due to old tools that are
making assumptions that a directory can never be a symlink to another
directory, and it's a big hazzle to compile separate kernels for them.This patch turns CONFIG_SYSFS_DEPRECATED into a run time option
that can be switched on/off the kernel command line. This way
the same binary can be used in both cases with just a option
on the command line.The old CONFIG_SYSFS_DEPRECATED_V2 option is still there to set
the default. I kept the weird name to not break existing
config files.Also the compat code can be still completely disabled by undefining
CONFIG_SYSFS_DEPRECATED_SWITCH -- just the optimizer takes
care of this now instead of lots of ifdefs. This makes the code
look nicer.v2: This is an updated version on top of Kay's patch to only
handle the block devices. I tested it on my old systems
and that seems to work.Cc: axboe@kernel.dk
Signed-off-by: Andi Kleen
Cc: Kay Sievers
Signed-off-by: Greg Kroah-Hartman -
This patch removes the old CONFIG_SYSFS_DEPRECATED_V2 config option,
but it keeps the logic around to handle block devices in the old manner
as some people like to run new kernel versions on old (pre 2007/2008)
distros.Signed-off-by: Kay Sievers
Cc: Jens Axboe
Cc: Stephen Hemminger
Cc: "Eric W. Biederman"
Cc: Alan Stern
Cc: "James E.J. Bottomley"
Cc: Andrew Morton
Cc: Alexey Kuznetsov
Cc: Randy Dunlap
Cc: Tejun Heo
Cc: "David S. Miller"
Cc: Jaroslav Kysela
Cc: Takashi Iwai
Cc: Ingo Molnar
Cc: Peter Zijlstra
Cc: David Howells
Signed-off-by: Greg Kroah-Hartman -
There's no need to explicitly check for data and resources being NULL,
as platform_device_add_{data,resources}() do this internally nowadays.This makes the code more linear and less indented.
Signed-off-by: Anton Vorontsov
Signed-off-by: Greg Kroah-Hartman -
Some users of platform_device_add_{data,resources}() assume that
NULL data and resources will be handled specially, i.e. just ignored.But the platform core ends up calling kmemdup(NULL, 0, ...), which
returns a non-NULL result (i.e. ZERO_SIZE_PTR), which causes drivers
to oops on a valid code, something like:if (platform_data)
stuff = platform_data->stuff;This patch makes the platform core a bit more safe for such cases.
Signed-off-by: Anton Vorontsov
Signed-off-by: Greg Kroah-Hartman -
Currently, the platform_bus allows customization of several of the
busses dev_pm_ops methods by using weak symbols so that platform code
can override them. The weak-symbol approach is not scalable when
wanting to support multiple platforms in a single kernel binary.Instead, provide __init methods for platform code to customize the
dev_pm_ops methods at runtime.NOTE: after these dynamic methods are merged, the weak symbols should
be removed from drivers/base/platform.c. AFAIK, this will only
affect SH and sh-mobile which should be converted to use this
runtime approach instead of the weak symbols. After SH &
sh-mobile are converted, the weak symobols could be removed.Tested on OMAP3.
Cc: Magnus Damm
Acked-by: Grant Likely
Signed-off-by: Kevin Hilman
Signed-off-by: Greg Kroah-Hartman -
In theory (although not *yet* in practice), a driver being passed
to platform_driver_probe might have driver.bus set to something
other than platform_bus_type. Locking drv->driver.bus is always
correct.Signed-off-by: Patrick Pannuto
Signed-off-by: Greg Kroah-Hartman
22 Oct, 2010
2 commits
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* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: (26 commits)
PM / Wakeup: Show wakeup sources statistics in debugfs
PM: Introduce library for device-specific OPPs (v7)
PM: Add sysfs attr for rechecking dev hash from PM trace
PM: Lock PM device list mutex in show_dev_hash()
PM / Runtime: Remove idle notification after failing suspend
PM / Hibernate: Modify signature used to mark swap
PM / Runtime: Reduce code duplication in core helper functions
PM: Allow wakeup events to abort freezing of tasks
PM: runtime: add missed pm_request_autosuspend
PM / Hibernate: Make some boot messages look less scary
PM / Runtime: Implement autosuspend support
PM / Runtime: Add no_callbacks flag
PM / Runtime: Combine runtime PM entry points
PM / Runtime: Merge synchronous and async runtime routines
PM / Runtime: Replace boolean arguments with bitflags
PM / Runtime: Move code in drivers/base/power/runtime.c
sysfs: Add sysfs_merge_group() and sysfs_unmerge_group()
PM: Fix potential issue with failing asynchronous suspend
PM / Wakeup: Introduce wakeup source objects and event statistics (v3)
PM: Fix signed/unsigned warning in dpm_show_time()
... -
The current code allocates and manages platform_devices created from
the device tree manually. It also uses an unsafe shortcut for
allocating the platform_device and the resource table at the same
time. (which I added in the last rework; sorry).This patch refactors the code to use platform_device_alloc() for
allocating new devices. This reduces the amount of custom code
implemented by of_platform, eliminates the unsafe alloc trick, and has
the side benefit of letting the platform_bus code manage freeing the
device data and resources when the device is freed.Signed-off-by: Grant Likely
Cc: Benjamin Herrenschmidt
Cc: Greg Kroah-Hartman
Cc: "David S. Miller"
Cc: Michal Simek
20 Oct, 2010
1 commit
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There may be wakeup sources that aren't associated with any devices
and their statistics information won't be available from sysfs. Also,
for debugging purposes it is convenient to have all of the wakeup
sources statistics available from one place. For these reasons,
introduce new file "wakeup_sources" in debugfs containing those
statistics.Signed-off-by: Rafael J. Wysocki
Acked-by: Greg Kroah-Hartman
17 Oct, 2010
15 commits
-
SoCs have a standard set of tuples consisting of frequency and
voltage pairs that the device will support per voltage domain. These
are called Operating Performance Points or OPPs. The actual
definitions of OPP varies over silicon versions. For a specific domain,
we can have a set of {frequency, voltage} pairs. As the kernel boots
and more information is available, a default set of these are activated
based on the precise nature of device. Further on operation, based on
conditions prevailing in the system (such as temperature), some OPP
availability may be temporarily controlled by the SoC frameworks.To implement an OPP, some sort of power management support is necessary
hence this library depends on CONFIG_PM.Contributions include:
Sanjeev Premi for the initial concept:
http://patchwork.kernel.org/patch/50998/
Kevin Hilman for converting original design to device-based.
Kevin Hilman and Paul Walmsey for cleaning up many of the function
abstractions, improvements and data structure handling.
Romit Dasgupta for using enums instead of opp pointers.
Thara Gopinath, Eduardo Valentin and Vishwanath BS for fixes and
cleanups.
Linus Walleij for recommending this layer be made generic for usage
in other architectures beyond OMAP and ARM.
Mark Brown, Andrew Morton, Rafael J. Wysocki, Paul E. McKenney for
valuable improvements.Discussions and comments from:
http://marc.info/?l=linux-omap&m=126033945313269&w=2
http://marc.info/?l=linux-omap&m=125482970102327&w=2
http://marc.info/?t=125809247500002&r=1&w=2
http://marc.info/?l=linux-omap&m=126025973426007&w=2
http://marc.info/?t=128152609200064&r=1&w=2
http://marc.info/?t=128468723000002&r=1&w=2
incorporated.v1: http://marc.info/?t=128468723000002&r=1&w=2
Signed-off-by: Nishanth Menon
Signed-off-by: Kevin Hilman
Signed-off-by: Rafael J. Wysocki -
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: James Hogan
Signed-off-by: Rafael J. Wysocki -
Lock the PM device list mutex using device_pm_lock() and
device_pm_unlock() around the list iteration in show_dev_hash().show_dev_hash() was reverse iterating dpm_list without first locking the
mutex that the functions in drivers/base/power/main.c lock. I assume
this was unintentional since there is no comment suggesting why the lock
might not be necessary.Signed-off-by: James Hogan
Signed-off-by: Rafael J. Wysocki -
If runtime suspend of a device fails returning -EAGAIN or -EBUSY,
which means that it's safe to try to suspend it again, the PM core
runs the runtime idle helper function for it. Unfortunately this may
lead to problems, for example for PCI devices whose drivers don't
implement the ->runtime_idle() callback, because in that case the
PCI bus type's ->runtime_idle() always calls pm_runtime_suspend()
for the given device. Then, if there's an automatic idle
notification after the driver's ->runtime_suspend() returning -EAGAIN
or -EBUSY, it will make the suspend happen again possibly causing a
busy loop to appear. To avoid that, remove the idle notification
after failing runtime suspend of a device altogether and let the
callers of pm_runtime_suspend() repeat the operation if need be.Signed-off-by: Rafael J. Wysocki
Acked-by: Alan Stern -
Reduce code duplication in rpm_idle(), rpm_suspend() and rpm_resume()
by using local pointers to store callback addresses and moving some
duplicated code into a separate function.Signed-off-by: Rafael J. Wysocki
Reviewed-by: Alan Stern -
This patch (as1427) implements the "autosuspend" facility for runtime
PM. A few new fields are added to the dev_pm_info structure and
several new PM helper functions are defined, for telling the PM core
whether or not a device uses autosuspend, for setting the autosuspend
delay, and for marking periods of device activity.Drivers that do not want to use autosuspend can continue using the
same helper functions as before; their behavior will not change. In
addition, drivers supporting autosuspend can also call the old helper
functions to get the old behavior.The details are all explained in Documentation/power/runtime_pm.txt
and Documentation/ABI/testing/sysfs-devices-power.Signed-off-by: Alan Stern
Signed-off-by: Rafael J. Wysocki -
Some devices, such as USB interfaces, cannot be power-managed
independently of their parents, i.e., they cannot be put in low power
while the parent remains at full power. This patch (as1425) creates a
new "no_callbacks" flag, which tells the PM core not to invoke the
runtime-PM callback routines for the such devices but instead to
assume that the callbacks always succeed. In addition, the
non-debugging runtime-PM sysfs attributes for the devices are removed,
since they are pretty much meaningless.The advantage of this scheme comes not so much from avoiding the
callbacks themselves, but rather from the fact that without the need
for a process context in which to run the callbacks, more work can be
done in interrupt context.Signed-off-by: Alan Stern
Signed-off-by: Rafael J. Wysocki -
This patch (as1424) combines the various public entry points for the
runtime PM routines into three simple functions: one for idle, one for
suspend, and one for resume. A new bitflag specifies whether or not
to increment or decrement the usage_count field.The new entry points are named __pm_runtime_idle,
__pm_runtime_suspend, and __pm_runtime_resume, to reflect that they
are trampolines. Simultaneously, the corresponding internal routines
are renamed to rpm_idle, rpm_suspend, and rpm_resume.Signed-off-by: Alan Stern
Signed-off-by: Rafael J. Wysocki -
This patch (as1423) merges the asynchronous routines
__pm_request_idle(), __pm_request_suspend(), and __pm_request_resume()
with their synchronous counterparts. The RPM_ASYNC bitflag argument
serves to indicate what sort of operation to perform.In the course of performing this merger, it became apparent that the
various functions don't all behave consistenly with regard to error
reporting and cancellation of outstanding requests. A new routine,
rpm_check_suspend_allowed(), was written to centralize much of the
testing, and the other functions were revised to follow a simple
algorithm:If the operation is disallowed because of the device's
settings or current state, return an error.Cancel pending or scheduled requests of lower priority.
Schedule, queue, or perform the desired operation.
A few special cases and exceptions are noted in comments.
Signed-off-by: Alan Stern
Signed-off-by: Rafael J. Wysocki -
The "from_wq" argument in __pm_runtime_suspend() and
__pm_runtime_resume() supposedly indicates whether or not the function
was called by the PM workqueue thread, but in fact it isn't always
used this way. It really indicates whether or not the function should
return early if the requested operation is already in progress.Along with this badly-named boolean argument, later patches in this
series will add several other boolean arguments to these functions and
others. Therefore this patch (as1422) begins the conversion process
by replacing from_wq with a bitflag argument. The same bitflags are
also used in __pm_runtime_get() and __pm_runtime_put(), where they
indicate whether or not the operation should be asynchronous.Signed-off-by: Alan Stern
Signed-off-by: Rafael J. Wysocki -
This patch (as1421) moves the PM runtime accounting subroutines up to
the beginning of runtime.c, taking them out of the middle of the
functions that do the actual work. No operational changes.Signed-off-by: Alan Stern
Signed-off-by: Rafael J. Wysocki -
There is a potential issue with the asynchronous suspend code that
a device driver suspending asynchronously may not notice that it
should back off. There are two failing scenarions, (1) when the
driver is waiting for a driver suspending synchronously to complete
and that second driver returns error code, in which case async_error
won't be set and the waiting driver will continue suspending and (2)
after the driver has called device_pm_wait_for_dev() and the waited
for driver returns error code, in which case the caller of
device_pm_wait_for_dev() will not know that there was an error and
will continue suspending.To fix this issue make __device_suspend() set async_error, so
async_suspend() doesn't need to set it any more, and make
device_pm_wait_for_dev() return async_error, so that its callers
can check whether or not they should continue suspending.No more changes are necessary, since device_pm_wait_for_dev() is
not used by any drivers' suspend routines.Reported-by: Colin Cross
Signed-off-by: Rafael J. Wysocki
Acked-by: Greg Kroah-Hartman -
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: Rafael J. Wysocki
Acked-by: Greg Kroah-Hartman -
Seen on MIPS32, gcc 4.4.3, 2.6.36-rc4:
drivers/base/power/main.c: In function 'dpm_show_time':
drivers/base/power/main.c:415: warning: comparison of distinct pointer types lacks a castdo_div() takes unsigned parameters:
uint32_t do_div(uint64_t *n, uint32_t base);
Using an unsigned variable for usecs64 should not cause any problems,
because calltime >= starttime .Signed-off-by: Kevin Cernekee
Signed-off-by: Rafael J. Wysocki -
Allow drivers, that belong to subsystems which use the generic
runtime pm callbacks, not to define runtime pm suspend/resume handlers,
by implicitly assuming success in such cases.This is needed to eliminate nop handlers that would otherwise be
necessary by drivers which enable runtime pm, but don't need
to do anything when their devices are runtime-suspended/resumed.Signed-off-by: Ohad Ben-Cohen
Acked-by: Kevin Hilman
Acked-by: Mark Brown
Signed-off-by: Rafael J. Wysocki
21 Sep, 2010
1 commit
-
Merge reason: Pick up the latest fixes in -rc5.
Signed-off-by: Ingo Molnar
10 Sep, 2010
1 commit
-
Create attributes:
/sys/devices/system/cpu/cpuX/topology/book_id
/sys/devices/system/cpu/cpuX/topology/book_siblingswhich show the book id and the book siblings of a cpu.
Unlike the attributes for SMT and MC these attributes are only present if
CONFIG_SCHED_BOOK is set. There is no reason to pollute sysfs for every
architecture with unused attributes.Signed-off-by: Heiko Carstens
Signed-off-by: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar
09 Sep, 2010
1 commit
-
During suspend, the power.completion is expected to be set when a
device has not yet started suspending. Set it on init to fix a
corner case where a device is resumed when its parent has never
suspended.Consider three drivers, A, B, and C. The parent of A is C, and C
has async_suspend set. On boot, C->power.completion is initialized
to 0.During the first suspend:
suspend_devices_and_enter(...)
dpm_resume(...)
device_suspend(A)
device_suspend(B) returns error, aborts suspend
dpm_resume_end(...)
dpm_resume(...)
device_resume(A)
dpm_wait(A->parent == C)
wait_for_completion(C->power.completion)The wait_for_completion will never complete, because
complete_all(C->power.completion) will only be called from
device_suspend(C) or device_resume(C), neither of which is called
if suspend is aborted before C.After a successful suspend->resume cycle, where B doesn't abort
suspend, C->power.completion is left in the completed state by the
call to device_resume(C), and the same call path will work if B
aborts suspend.Signed-off-by: Colin Cross
Signed-off-by: Rafael J. Wysocki
