Commit 0998d06310 (device-core: Ensure drvdata = NULL when no
driver is bound) removes the need to set driver data field to
NULL.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This patch fixes the pointer position in r8192U_dm.c
to meet the kernel coding style conventions.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes the pointer position in r8192U_core.c
to meet the kernel coding style conventions.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes the following checkpatch warning:
WARNING: Prefer seq_puts to seq_printf
Signed-off-by: Hema Prathaban <hemaklnce@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes the following checkpatch warning:
WARNING: braces {} are not necessary for single statement blocks
Signed-off-by: Hema Prathaban <hemaklnce@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes the warning about switch case found by checkpatch.pl
in driver asus_oled.
Signed-off-by: Tülin İzer <tulinizer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A register write to hardware is reasonably unlikely to cause locking
dependency issues, the reason we're tainting is that unexpected changes
in the hardware configuration may confuse drivers.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
If range information has been provided then when we allocate a rbnode
within a range allocate the entire range. The goal is to minimise the
number of reallocations done when combining or extending blocks. At
present only readability and yes_ranges are taken into account, this is
expected to cover most cases efficiently.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
In preparation for being slightly smarter about how we allocate memory
factor out the node allocation.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Allow drivers to discard parts of the register cache, for example if part
of the hardware has been reset.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
All the drivers that need delay for the regulator voltage output voltage to
stabilize after being enabled or after being set to a new value has been
converted to implement enable_time and set_voltage_time_sel callbacks.
Then regulator core will take care of the necessary delay.
This patch removes the unneeded include of linux/delay.h in regulator drivers.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Cc: Daniel Jeong <daniel.jeong@ti.com>
Cc: Sangbeom Kim <sbkim73@samsung.com>
Cc: Chiwoong Byun <woong.byun@samsung.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
init_data is a pointer. Use NULL instead of 0.
Silences the following sparse warning:
drivers/regulator/isl6271a-regulator.c:133:44:
warning: Using plain integer as NULL pointer
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Since 0998d06310 "device-core: Ensure drvdata = NULL when no driver is bound",
this is done by driver core after device_release or on probe failure.
Thus we can remove all platform_set_drvdata(pdev, NULL) in drivers.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
abb->current_info_idx is used as array subscript to access volt_table,
thus the valid value range should be 0 ... desc->n_voltages - 1.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Adaptive Body Biasing (ABB) modulates transistor bias voltages
dynamically in order to optimize switching speed versus leakage.
Texas Instruments' SmartReflex 2 technology provides support for this
power management technique with Forward Body Biasing (FBB) and Reverse
Body Biasing (RBB). These modulate the body voltage of transistor
cells or blocks dynamically to gain performance and reduce leakage.
TI's SmartReflex white paper[1] has further information for usage in
conjunction with other power management techniques.
The application of FBB/RBB technique is determined for each unique
device in some process nodes, whereas, they are mandated on other
process nodes.
In a nutshell, ABB technique is implemented on TI SoC as an on-chip
LDO which has ABB module controlling the bias voltage. However, the
voltage is unique per device. These vary per SoC family and the manner
in which these techniques are used may vary depending on the Operating
Performance Point (OPP) voltage targeted. For example:
OMAP3630/OMAP4430: certain OPPs mandate usage of FBB independent of
devices.
OMAP4460/OMAP4470: certain OPPs mandate usage of FBB, while others may
optionally use FBB or optimization with RBB.
OMAP5: ALL OPPs may optionally use ABB, and ABB biasing voltage is
influenced by vset fused in s/w and requiring s/w override of
default values.
Further, two generations of ABB module are used in various TI SoCs.
They have remained mostly register field compatible, however the
register offset had switched between versions.
We introduce ABB LDO support in the form of a regulator which is
controlled by voltages denoting the desired Operating Performance
Point which is targeted. However, since ABB transition is part of OPP
change sequence, the sequencing required to ensure sane operation
w.r.t OPP change is left to the controlling driver (example: cpufreq
SoC driver) using standard regulator operations.
The driver supports all ABB modes and ability to override ABB LDO vset
control efuse based ABB mode detection etc.
Current implementation is heavily influenced by the original patch
series [2][3] from Mike Turquette. However, the current implementation
supports only device tree based information.
[1] http://www.ti.com/pdfs/wtbu/smartreflex_whitepaper.pdf
[2] http://marc.info/?l=linux-omap&m=134931341818379&w=2
[3] http://marc.info/?l=linux-arm-kernel&m=134931402406853&w=2
[nm@ti.com: co-developer]
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Andrii.Tseglytskyi <andrii.tseglytskyi@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
There is no clock pll2_pfd9_720m. Instead it should be pll3_pfd0_720m.
Fix the typo in gpu3d_shader_sels.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>
The diagnostic register holds the errata bits. Mostly bootloader
does not bring up secondary cores, so that when errata bits are set
in bootloader, they are set only for boot cpu. But on a SMP
configuration, it should be equally done on every single core.
Set up the diagnostic register for secondary cores by replicating
the register from boot cpu.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>
According to the i.MX6 Dual/Quad technical reference manual
(Figure 18-2. Clock Tree - Part 1) the MLB clock is directly
feed by the AXI_CLK_ROOT. This is called 'axi' in our code.
Note that the clock of the MLB IP block on the i.MX6 is completely
independent of the PLL8 (MLB PLL). The MLB PLL isn't responsible
for feeding the MLB IP block with a clock. Instead, it's used
internally by the MLB module to sync the bus clock in case the MLB
6-pin interface is enabled:
MediaLB Control 0 Register, MLB150_MLBC0[5], MLBPEN:
1 MediaLB 6-pin interface enabled. MLB PLL and MLB PHY is enabled in this case.
I.e. the PLL8 MLB PLL has to be handled by the MLB driver and isn't needed
for clocking the MLB module itself.
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
CC: Jiada Wang <Jiada_Wang@mentor.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
The periph_clk2_sel mux can be set to pll3, osc/pll1_ref_clk, or osc/
pll2_burn_in_clk. The periph2_clk2_sel mux can be set to pll3 or pll2.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Avoid waking up every thread sleeping in read call on an AF_UNIX
socket during suspend and resume by calling a freezable blocking
call. Previous patches modified the freezer to avoid sending
wakeups to threads that are blocked in freezable blocking calls.
This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Avoid waking up every thread sleeping in a sigtimedwait call during
suspend and resume by calling a freezable blocking call. Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.
This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Avoid waking up every thread sleeping in a nanosleep call during
suspend and resume by calling a freezable blocking call. Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.
This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Avoid waking up every thread sleeping in a futex_wait call during
suspend and resume by calling a freezable blocking call. Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.
This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Avoid waking up every thread sleeping in a select call during
suspend and resume by calling a freezable blocking call. Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.
This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Avoid waking up every thread sleeping in an epoll_wait call during
suspend and resume by calling a freezable blocking call. Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.
This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Avoid waking up every thread sleeping in a binder call during
suspend and resume by calling a freezable blocking call. Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.
This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Freezing tasks will wake up almost every userspace task from
where it is blocking and force it to run until it hits a
call to try_to_sleep(), generally on the exit path from the syscall
it is blocking in. On resume each task will run again, usually
restarting the syscall and running until it hits the same
blocking call as it was originally blocked in.
To allow tasks to avoid running on every suspend/resume cycle,
this patch adds additional freezable wrappers around blocking calls
that call freezer_do_not_count(). Combined with the previous patch,
these tasks will not run during suspend or resume unless they wake
up for another reason, in which case they will run until they hit
the try_to_freeze() in freezer_count(), and then continue processing
the wakeup after tasks are thawed.
Additional patches will convert the most common locations that
userspace blocks in to use freezable helpers.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Some of the freezable helpers have to be macros because their
condition argument needs to get evaluated every time through
the wait loop. Convert the others to static inline to make
future changes easier.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Freezing tasks will wake up almost every userspace task from
where it is blocking and force it to run until it hits a
call to try_to_sleep(), generally on the exit path from the syscall
it is blocking in. On resume each task will run again, usually
restarting the syscall and running until it hits the same
blocking call as it was originally blocked in.
Convert the existing wait_event_freezable* wrappers to use
freezer_do_not_count(). Combined with a previous patch,
these tasks will not run during suspend or resume unless they wake
up for another reason, in which case they will run until they hit
the try_to_freeze() in freezer_count(), and then continue processing
the wakeup after tasks are thawed.
This results in a small change in behavior, previously a race
between freezing and a normal wakeup would be won by the wakeup,
now the task will freeze and then handle the wakeup after thawing.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Android goes through suspend/resume very often (every few seconds when
on a busy wifi network with the screen off), and a significant portion
of the energy used to go in and out of suspend is spent in the
freezer. If a task has called freezer_do_not_count(), don't bother
waking it up. If it happens to wake up later it will call
freezer_count() and immediately enter the refrigerator.
Combined with patches to convert freezable helpers to use
freezer_do_not_count() and convert common sites where idle userspace
tasks are blocked to use the freezable helpers, this reduces the
time and energy required to suspend and resume.
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
All tasks can easily be frozen in under 10 ms, switch to using
an initial 1 ms sleep followed by exponential backoff until
8 ms. Also convert the printed time to ms instead of centiseconds.
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We shouldn't try_to_freeze if locks are held. Holding a lock can cause a
deadlock if the lock is later acquired in the suspend or hibernate path
(e.g. by dpm). Holding a lock can also cause a deadlock in the case of
cgroup_freezer if a lock is held inside a frozen cgroup that is later
acquired by a process outside that group.
History:
This patch was originally applied as 6aa9707099 and reverted in
dbf520a9d7 because NFS was freezing with locks held. It was
deemed better to keep the bad freeze point in NFS to allow laptops
to suspend consistently. The previous patch in this series converts
NFS to call _unsafe versions of the freezable helpers so that
lockdep doesn't complain about them until a more correct fix
can be applied.
[akpm@linux-foundation.org: export debug_check_no_locks_held]
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The only existing caller to debug_check_no_locks_held calls it
with 'current' as the task, and the freezer needs to call
debug_check_no_locks_held but doesn't already have a current
task pointer, so remove the argument. It is already assuming
that the current task is relevant by dumping the current stack
trace as part of the warning.
This was originally part of 6aa9707099 (lockdep: check that
no locks held at freeze time) which was reverted in
dbf520a9d7.
Original-author: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
CIFS calls wait_event_freezekillable_unsafe with a VFS lock held,
which is unsafe and will cause lockdep warnings when 6aa9707
"lockdep: check that no locks held at freeze time" is reapplied
(it was reverted in dbf520a). CIFS shouldn't be doing this, but
it has long-running syscalls that must hold a lock but also
shouldn't block suspend. Until CIFS freeze handling is rewritten
to use a signal to exit out of the critical section, add a new
wait_event_freezekillable_unsafe helper that will not run the
lockdep test when 6aa9707 is reapplied, and call it from CIFS.
In practice the likley result of holding the lock while freezing
is that a second task blocked on the lock will never freeze,
aborting suspend, but it is possible to manufacture a case using
the cgroup freezer, the lock, and the suspend freezer to create
a deadlock. Silencing the lockdep warning here will allow
problems to be found in other drivers that may have a more
serious deadlock risk, and prevent new problems from being added.
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
NFS calls the freezable helpers with locks held, which is unsafe
and will cause lockdep warnings when 6aa9707 "lockdep: check
that no locks held at freeze time" is reapplied (it was reverted
in dbf520a). NFS shouldn't be doing this, but it has
long-running syscalls that must hold a lock but also shouldn't
block suspend. Until NFS freeze handling is rewritten to use a
signal to exit out of the critical section, add new *_unsafe
versions of the helpers that will not run the lockdep test when
6aa9707 is reapplied, and call them from NFS.
In practice the likley result of holding the lock while freezing
is that a second task blocked on the lock will never freeze,
aborting suspend, but it is possible to manufacture a case using
the cgroup freezer, the lock, and the suspend freezer to create
a deadlock. Silencing the lockdep warning here will allow
problems to be found in other drivers that may have a more
serious deadlock risk, and prevent new problems from being added.
Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Introduce .offline() and .online() callbacks for memory_subsys
that will allow the generic device_offline() and device_online()
to be used with device objects representing memory blocks. That,
in turn, allows the ACPI subsystem to use device_offline() to put
removable memory blocks offline, if possible, before removing
memory modules holding them.
The 'online' sysfs attribute of memory block devices will attempt to
put them offline if 0 is written to it and will attempt to apply the
previously used online type when onlining them (i.e. when 1 is
written to it).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
During ACPI memory hotplug configuration bind memory blocks residing
in modules removable through the standard ACPI mechanism to struct
acpi_device objects associated with ACPI namespace objects
representing those modules. Accordingly, unbind those memory blocks
from the struct acpi_device objects when the memory modules in
question are being removed.
When "offline" operation for devices representing memory blocks is
introduced, this will allow the ACPI core's device hot-remove code to
use it to carry out remove_memory() for those memory blocks and check
the results of that before it actually removes the modules holding
them from the system.
Since walk_memory_range() is used for accessing all memory blocks
corresponding to a given ACPI namespace object, it is exported from
memory_hotplug.c so that the code in acpi_memhotplug.c can use it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Split the ACPI processor driver into two parts, one that is
non-modular, resides in the ACPI core and handles the enumeration
and hotplug of processors and one that implements the rest of the
existing processor driver functionality.
The non-modular part uses an ACPI scan handler object to enumerate
processors on the basis of information provided by the ACPI namespace
and to hook up with the common ACPI hotplug infrastructure. It also
populates the ACPI handle of each processor device having a
corresponding object in the ACPI namespace, which allows the driver
proper to bind to those devices, and makes the driver bind to them
if it is readily available (i.e. loaded) when the scan handler's
.attach() routine is running.
There are a few reasons to make this change.
First, switching the ACPI processor driver to using the common ACPI
hotplug infrastructure reduces code duplication and size considerably,
even though a new file is created along with a header comment etc.
Second, since the common hotplug code attempts to offline devices
before starting the (non-reversible) removal procedure, it will abort
(and possibly roll back) hot-remove operations involving processors
if cpu_down() returns an error code for one of them instead of
continuing them blindly (if /sys/firmware/acpi/hotplug/force_remove
is unset). That is a more desirable behavior than what the current
code does.
Finally, the separation of the scan/hotplug part from the driver
proper makes it possible to simplify the driver's .remove() routine,
because it doesn't need to worry about the possible cleanup related
to processor removal any more (the scan/hotplug part is responsible
for that now) and can handle device removal and driver removal
symmetricaly (i.e. as appropriate).
Some user-visible changes in sysfs are made (for example, the
'sysdev' link from the ACPI device node to the processor device's
directory is gone and a 'physical_node' link is present instead
and a corresponding 'firmware_node' is present in the processor
device's directory, the processor driver is now visible under
/sys/bus/cpu/drivers/ and bound to the processor device), but
that shouldn't affect the functionality that users care about
(frequency scaling, C-states and thermal management).
Tested on my venerable Toshiba Portege R500.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Modify the generic ACPI hotplug code to be able to check if devices
scheduled for hot-removal may be gracefully removed from the system
using the device offline/online mechanism introduced previously.
Namely, make acpi_scan_hot_remove() handling device hot-removal call
device_offline() for all physical companions of the ACPI device nodes
involved in the operation and check the results. If any of the
device_offline() calls fails, the function will not progress to the
removal phase (which cannot be aborted), unless its (new) force
argument is set (in case of a failing offline it will put the devices
offlined by it back online).
In support of 'forced' device hot-removal, add a new sysfs attribute
'force_remove' that will reside under /sys/firmware/acpi/hotplug/.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Rework the CPU hotplug code in drivers/base/cpu.c to use the
generic offline/online support introduced previously instead of
its own CPU-specific code.
For this purpose, modify cpu_subsys to provide offline and online
callbacks for CONFIG_HOTPLUG_CPU set and remove the code handling
the CPU-specific 'online' sysfs attribute.
This modification is not supposed to change the user-observable
behavior of the kernel (i.e. the 'online' attribute will be present
in exactly the same place in sysfs and should trigger exactly the
same actions as before).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
In some cases, graceful hot-removal of devices is not possible,
although in principle the devices in question support hotplug.
For example, that may happen for the last CPU in the system or
for memory modules holding kernel memory.
In those cases it is nice to be able to check if the given device
can be gracefully hot-removed before triggering a removal procedure
that cannot be aborted or reversed. Unfortunately, however, the
kernel currently doesn't provide any support for that.
To address that deficiency, introduce support for offline and
online operations that can be performed on devices, respectively,
before a hot-removal and in case when it is necessary (or convenient)
to put a device back online after a successful offline (that has not
been followed by removal). The idea is that the offline will fail
whenever the given device cannot be gracefully removed from the
system and it will not be allowed to use the device after a
successful offline (until a subsequent online) in analogy with the
existing CPU offline/online mechanism.
For now, the offline and online operations are introduced at the
bus type level, as that should be sufficient for the most urgent use
cases (CPUs and memory modules). In the future, however, the
approach may be extended to cover some more complicated device
offline/online scenarios involving device drivers etc.
The lock_device_hotplug() and unlock_device_hotplug() functions are
introduced because subsequent patches need to put larger pieces of
code under device_hotplug_lock to prevent race conditions between
device offline and removal from happening.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
* acpi-fixes:
ACPI / AC: Add sleep quirk for Thinkpad e530
ACPI / EC: Restart transaction even when the IBF flag set
ACPI video: ignore BIOS initial backlight value for HP 1000
ACPI: Fix section to __init. Align with usage in acpixf.h
ACPI / PM: Move processor suspend/resume to syscore_ops
Fix dev_pm_put_subsys_data() so that it doesn't call kfree() under
a spinlock and make it return 1 whenever it leaves NULL
power.subsys_data (regardless of the reason).
Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The driver can no longer be built as a module remove the compile fence
around cpufreq tracing call.
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
