Pull thermal management updates from Zhang Rui:
"This time we only have a few changes as there are no soc thermal
changes from Eduardo. The only big change is the introduction of
TMON, a tool to help visualize, tune, and test the thermal subsystem.
The rest is mostly cleanups and fixes all over.
Specifics:
- introduce TMON, a tool base on thermal sysfs I/F. It can be used
to visualize, tune and test the thermal subsystem.
- fix a zone/cooling device binding problem, when both thermal zone
bind parameters and .bind() callback are available"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
tools/thermal: Introduce tmon, a tool for thermal subsystem
thermal: Fix binding problem when there is thermal zone params
thermal: cpu_cooling: fix return value check in cpufreq_cooling_register()
Thermal: Check for validity before doing kfree
thermal/intel_powerclamp: Add newer CPU models
Thermal: Tidy up error handling in powerclamp_init
thermal: Kconfig: cosmetic fixes
ACPI/thermal : Remove zone disabled warning
typo in drivers/thermal/Kconfig: lpatform instead of platform
CONFIG_CPU_FREQ_TABLE will be always enabled when cpufreq framework is used, as
cpufreq core depends on it. So, we don't need this CONFIG option anymore as it
is not configurable. Remove CONFIG_CPU_FREQ_TABLE and update its users.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In order to improve code organization, this patch
moves the hwmon sysfs support to a file named
thermal_hwmon. This helps to add extra support
for hwmon without scrambling the code.
In order to do this move, the hwmon list head is now
using its own locking. Before, the list used
the global thermal locking. Also, some minor changes
in the code were required, as recommended by checkpatch.pl.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
This movement of files is done for easy maintenance and adding more
new sensor's support for exynos platform easily . This will also help in
bifurcating exynos common, sensor driver and sensor data related parts.
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
This is based on the initial imx thermal work done by
Rob Lee <rob.lee@linaro.org> (Not sure if the email address is still
valid). Since he is no longer interested in the work and I have
rewritten a significant amount of the code, I just took the authorship
over from him.
It adds the imx thermal support using Temperature Monitor (TEMPMON)
block found on some Freescale i.MX SoCs. The driver uses syscon regmap
interface to access TEMPMON control registers and calibration data, and
supports cpufreq as the cooling device.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Fix build error in x86_pkg_temp_thermal.c. It requires that
X86_MCE & X86_THERMAL_VECTOR be enabled, so depend on the latter symbol,
since it depends on X86_MCE (indirectly).
Also, X86_PKG_TEMP_THERMAL is already inside an "if THERMAL" block,
so remove that duplicated dependency.
ERROR: "platform_thermal_package_rate_control" [drivers/thermal/x86_pkg_temp_thermal.ko] undefined!
ERROR: "platform_thermal_package_notify" [drivers/thermal/x86_pkg_temp_thermal.ko] undefined!
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This driver register CPU digital temperature sensor as a thermal
zone at package level.
Each package will show up as one zone with at max two trip points.
These trip points can be both read and updated. Once a non zero
value is set in the trip point, if the package package temperature
goes above or below this setting, a thermal notification is
generated.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
There is no support for hotplug or any other means of reducing
temperature. So, this patch removes these references from Kconfig.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Acked-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Because this feature is for debuging purposes, it is highly
recommended to do not enable this on production systems.
This patch adds warnings for system integrators, so that
people are aware of this potential security issue.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This removes the driver specific sysfs support of the temperature
emulation and uses the newly added core thermal framework for thermal
emulation. An exynos platform specific handler is added to support this.
In this patch, the exynos senor(tmu) related code and exynos framework
related (thermal zone, cooling devices) code are intentionally kept separate.
So an emulated function pointer is passed from sensor to framework. This is
beneficial in adding more sensor support using the same framework code
which is an ongoing work. The goal is to finally split them totally. Even
the existing read_temperature also follows the same execution method.
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This driver supports both Armada 370 and Armada XP SoC
thermal management controllers.
Armada 370 has a register to check a valid temperature, whereas
Armada XP does not. Each has a different initialization (i.e. calibration)
function. The temperature conversion formula is the same for both.
The controller present in each SoC have a very similar feature set,
so it corresponds to have one driver to support both of them.
Although this driver may present similarities to Dove and Kirkwood
thermal driver, the exact differences and coincidences are not fully
known. For this reason, support is given through a separate driver.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Currently, we have three Kconfig options for thermal governors, aka,
CONFIG_FAIR_SHARE, CONFIG_USER_SPACE and CONFIG_STEP_WISE.
But these names are too generic that may bring confusion to users.
Rename them to CONFIG_THERMAL_GOV_FAIR_SHARE,
CONFIG_THERMAL_GOV_USER_SPACE, CONFIG_THERMAL_GOV_STEP_WISE
to avoid the generic naming.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
The Marvell Dove SoC has a thermal sensor. Add a driver using the
thermal framework.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This patch adds support for Kirkwood 88F6282 and 88F6283 thermal sensor.
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This patch adds support to set the emulated temperature method in
thermal zone (sensor). After setting this feature thermal zone may
report this temperature and not the actual temperature. The emulation
implementation may be based on sensor capability through platform
specific handler or pure software emulation if no platform handler defined.
This is useful in debugging different temperature threshold and its
associated cooling action. Critical threshold's cannot be emulated.
Writing 0 on this node should disable emulation.
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Intel PowerClamp driver performs synchronized idle injection across
all online CPUs. The goal is to maintain a given package level C-state
ratio.
Compared to other throttling methods already exist in the kernel,
such as ACPI PAD (taking CPUs offline) and clock modulation, this is often
more efficient in terms of performance per watt.
Please refer to Documentation/thermal/intel_powerclamp.txt for more details.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This patch supports exynos's emulation mode with newly created sysfs node.
Exynos 4x12 (4212, 4412) and 5 series provide emulation mode for thermal
management unit. Thermal emulation mode supports software debug for TMU's
operation. User can set temperature manually with software code and TMU
will read current temperature from user value not from sensor's value.
This patch includes also documentary placed under Documentation/thermal/.
Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Pull trivial branch from Jiri Kosina:
"Usual stuff -- comment/printk typo fixes, documentation updates, dead
code elimination."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
HOWTO: fix double words typo
x86 mtrr: fix comment typo in mtrr_bp_init
propagate name change to comments in kernel source
doc: Update the name of profiling based on sysfs
treewide: Fix typos in various drivers
treewide: Fix typos in various Kconfig
wireless: mwifiex: Fix typo in wireless/mwifiex driver
messages: i2o: Fix typo in messages/i2o
scripts/kernel-doc: check that non-void fcts describe their return value
Kernel-doc: Convention: Use a "Return" section to describe return values
radeon: Fix typo and copy/paste error in comments
doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c
various: Fix spelling of "asynchronous" in comments.
Fix misspellings of "whether" in comments.
eisa: Fix spelling of "asynchronous".
various: Fix spelling of "registered" in comments.
doc: fix quite a few typos within Documentation
target: iscsi: fix comment typos in target/iscsi drivers
treewide: fix typo of "suport" in various comments and Kconfig
treewide: fix typo of "suppport" in various comments
...
As thermal drivers can be built as modules and also
the thermal framework itself, building cpu cooling
only as built-in can cause linking errors. For instance:
* Generic Thermal sysfs driver
*
Generic Thermal sysfs driver (THERMAL) [M/n/y/?] m
generic cpu cooling support (CPU_THERMAL) [N/y/?] (NEW) y
with the following drive:
CONFIG_OMAP_BANDGAP=m
generates:
ERROR: "cpufreq_cooling_unregister" [drivers/staging/omap-thermal/omap-thermal.ko] undefined!
ERROR: "cpufreq_cooling_register" [drivers/staging/omap-thermal/omap-thermal.ko] undefined!
This patch changes cpu cooling driver to allow it
to be built as module.
Reported-by: Enric Balletbo i Serra <eballetbo@gmail.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Reviewed-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This driver is based on the thermal management framework in thermal_sys.c. A
thermal zone device is created with the trip points to which cooling devices
can be bound, the current cooling device is cpufreq, e.g. CPU frequency is
clipped down to cool the CPU, and other cooling devices can be added and bound
to the trip points dynamically. The platform specific PRCMU interrupts are
used to active thermal update when trip points are reached.
Signed-off-by: hongbo.zhang <hongbo.zhang@linaro.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Francesco Lavra <francescolavra.fl@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This patch provides option to choose the default thermal
governor. If no option is provided, the step_wise
governor is selected by default.
Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This patch registers a governor which will let the
user land manage the platform thermals. Whenever a
trip happens, this governor just notifies the user
space using kobj_uevent().
Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This patch adds a simple step_wise governor to the
generic thermal layer. This algorithm throttles the
cooling devices in a linear fashion. If the 'trend'
is heating, it throttles by one step. And if the
thermal trend is cooling it de-throttles by one step.
This actually moves the throttling logic from thermal_sys.c
and puts inside step_wise.c, without any change.
Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This patch introduces a simple 'weight' based
governor named fair_share governor. Whenever the
thermal framework gets notified of the trip point
violation, this governor (if configured), throttles
the cooling devices associated with a thermal zone.
This mapping between a thermal zone and a cooling device
and the effectiveness of cooling are provided in the
platform layer.
Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Commit 0236141837 ("thermal: add generic cpufreq cooling
implementation") requires cpufreq_frequency_get_table(), but that
function is only defined for CONFIG_CPU_FREQ_TABLE resulting in the
following build error:
drivers/built-in.o: In function `cpufreq_get_max_state':
drivers/thermal/cpu_cooling.c:259: undefined reference to `cpufreq_frequency_get_table'
drivers/built-in.o: In function `get_cpu_frequency':
drivers/thermal/cpu_cooling.c:129: undefined reference to `cpufreq_frequency_get_table'
Fix it by selecting CONFIG_CPU_FREQ_TABLE for such a configuration.
It turns out CONFIG_EXYNOS_THERMAL also needs CONFIG_CPU_FREQ_TABLE, so
select it there as well.
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Insert exynos5 TMU sensor changes into the thermal driver. Some exynos4
changes are made generic for exynos series.
[akpm@linux-foundation.org: fix comment layout]
Signed-off-by: SangWook Ju <sw.ju@samsung.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@linaro.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Durgadoss <durgadoss.r@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This movement is needed because the hwmon entries and corresponding sysfs
interface is a duplicate of utilities already provided by
driver/thermal/thermal_sys.c. The goal is to place it in thermal folder
and add necessary functions to use the in-kernel thermal interfaces.
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@linaro.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: SangWook Ju <sw.ju@samsung.com>
Cc: Durgadoss <durgadoss.r@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This patchset introduces a new generic cooling device based on cpufreq
that can be used on non-ACPI platforms. As a proof of concept, we have
drivers for the following platforms using this mechanism now:
* Samsung Exynos (Exynos4 and Exynos5) in the current patchset.
* Freescale i.MX (git://git.linaro.org/people/amitdanielk/linux.git imx6q_thermal)
There is a small change in cpufreq cooling registration APIs, so a minor
change is needed for Freescale platforms.
Brief Description:
1) The generic cooling devices code is placed inside driver/thermal/*
as placing inside acpi folder will need un-necessary enabling of acpi
code. This code is architecture independent.
2) This patchset adds generic cpu cooling low level implementation
through frequency clipping. In future, other cpu related cooling
devices may be added here. An ACPI version of this already exists
(drivers/acpi/processor_thermal.c) .But this will be useful for
platforms like ARM using the generic thermal interface along with the
generic cpu cooling devices. The cooling device registration API's
return cooling device pointers which can be easily binded with the
thermal zone trip points. The important APIs exposed are,
a) struct thermal_cooling_device *cpufreq_cooling_register(
struct cpumask *clip_cpus)
b) void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
3) Samsung exynos platform thermal implementation is done using the
generic cpu cooling APIs and the new trip type. The temperature sensor
driver present in the hwmon folder(registered as hwmon driver) is moved
to thermal folder and registered as a thermal driver.
A simple data/control flow diagrams is shown below,
Core Linux thermal <-----> Exynos thermal interface <----- Temperature Sensor
| |
\|/ |
Cpufreq cooling device <---------------
TODO:
*Will send the DT enablement patches later after the driver is merged.
This patch:
Add support for generic cpu thermal cooling low level implementations
using frequency scaling up/down based on the registration parameters.
Different cpu related cooling devices can be registered by the user and
the binding of these cooling devices to the corresponding trip points can
be easily done as the registration APIs return the cooling device pointer.
The user of these APIs are responsible for passing clipping frequency .
The drivers can also register to recieve notification about any cooling
action called.
[akpm@linux-foundation.org: fix comment layout]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@linaro.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: SangWook Ju <sw.ju@samsung.com>
Cc: Durgadoss <durgadoss.r@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This patch add basic Renesas R-Car thermal sensor support.
It was tested on R-Car H1 Marzen board.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
SPEAr platforms now support DT and so must convert all drivers to support
DT. This patch adds DT probing support for SPEAr thermal sensor driver
and updates its documentation too.
Also, as SPEAr is the only user of this driver and is only available with
DT, make this an only DT driver. So, platform_data is completely removed
and passed via DT now.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@st.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
ST's SPEAr13xx machines are based on CortexA9 ARM processors. These
machines contain a thermal sensor for junction temperature monitoring.
This patch adds support for this thermal sensor in existing thermal
framework.
[akpm@linux-foundation.org: little code cleanup]
[akpm@linux-foundation.org: print the pointer correctly]
[viresh.kumar@st.com: thermal/spear_thermal: add compilation dependency on PLAT_SPEAR]
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
It's about time to revert 16d7523973 ("thermal: Create
CONFIG_THERMAL_HWMON=n"). Anybody running a kernel >= 2.6.40 would also
be running a recent enough version of lm-sensors.
Actually having CONFIG_THERMAL_HWMON is pretty convenient so instead of
dropping it, we keep it but hide it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Rene Herman <rene.herman@gmail.com>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Several ACPI drivers fail to build if CONFIG_NET is unset, because
they refer to things depending on CONFIG_THERMAL that in turn depends
on CONFIG_NET. However, CONFIG_THERMAL doesn't really need to depend
on CONFIG_NET, because the only part of it requiring CONFIG_NET is
the netlink interface in thermal_sys.c.
Put the netlink interface in thermal_sys.c under #ifdef CONFIG_NET
and remove the dependency of CONFIG_THERMAL on CONFIG_NET from
drivers/thermal/Kconfig.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Len Brown <lenb@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Luming Yu <luming.yu@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds event notification support to the generic
thermal sysfs framework in the kernel. The notification is in the
form of a netlink event.
Signed-off-by: R.Durgadoss <durgadoss.r@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Otherwise THERMAL_HWMON can be selected when HWMON=n and THERMAL=n, which
fails to build.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
A bug in libsensors <= 2.10.6 is exposed
when this new hwmon I/F is enabled.
Create CONFIG_THERMAL_HWMON=n
until some time after libsensors 2.10.7 ships
so those users can run the latest kernel.
libsensors 3.x is already fixed -- those users
can use CONFIG_THERMAL_HWMON=y now.
Signed-off-by: Rene Herman <rene.herman@gmail.com>
Acked-by: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Build the generic thermal driver as module "thermal_sys".
Make ACPI thermal, video, processor and fan SELECT the generic
thermal driver, as these drivers rely on it to build the sysfs I/F.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Len Brown <len.brown@intel.com>
The generic thermal I/F gets selected by ACPI_THERMAL --
its only current customer.
it doesn't need to clutter other configs by default.
Signed-off-by: Len Brown <len.brown@intel.com>
This reverts commit 3152fb9f11.
This broke libsensors.
Acked-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Linus Torvalds