The Energy Model (EM) can be registered in two ways:
1) Using a helper function, which under the hood relies on OPP framework
and DT entry in CPU node: 'dynamic-power-coefficient'. This is
a 'simple' EM because it's tied to the math formula:
Power = dynamic-power-coefficient * V^2 * f
2) Using em_dev_register_perf_domain() API function with a driver
custom callback which provides power for each performance state.
This is 'advanced' EM, since it can better reflect real power
measurements for each performance state. It's not limited to any
math formula and can better reflect real physics of the device.
Add description of these two methods to the documentation, so developers
could choose the suitable registration method (option).
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The Energy Model (EM) registration for CPUs should now be done using
a dedicated callback added recently into CPUFreq framework and drivers.
Commit c17495b01b ("cpufreq: Add callback to register with energy model")
The callback guaranties that the EM registration is called at the right
time during driver setup. To avoid mistakes update the documentation
to align with the existing code implementation.
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Improve the existing documentation of the Energy Model and add kernel-doc
comments. This extends an API description and helps better understanding
the usage.
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Recent changes to the PM core allows ->runtime_suspend|resume callbacks to
be unassigned.
In the earlier behaviour the PM core would return -ENOSYS, when trying to
runtime resume a device, for example. Let's update the documentation to
clarify this.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
pm_runtime_get_sync(), contradictory to intuition, does not drop the
runtime PM usage counter on errors which lead to several wrong usages in
drivers (missing the put). pm_runtime_resume_and_get() was added as a
better implementation so document the preference of using it, hoping it
will stop bad patterns.
Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
[ rjw: Documentation change edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull power supply and reset updates from Sebastian Reichel:
"battery/charger driver changes:
- core:
- provide function stubs if CONFIG_POWER_SUPPLY=n
- reduce loglevel for probe defer info
- surface:
- new battery and charger drivers for Surface
- bq27xxx:
- add bq78z100 support
- fix current_now/power_avg for newer chips
- cw2015:
- add CHARGE_NOW support
- ab8500:
- drop pdata support
- convert most DT bindings to YAML
- lots of minor fixes and cleanups
reset drivers:
- ltc2952-poweroff:
- make trigger delay configurable from DT
- minor fixes and cleanups"
* tag 'for-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply: (97 commits)
power: supply: cpcap-battery: fix invalid usage of list cursor
power: supply: bq256xx: add kerneldoc for structure members
power: supply: act8945a: correct kerneldoc
power: supply: max17040: remove unneeded double cast
power: supply: max17040: handle device_property_read_u8_array() failure
power: supply: max14577: remove unneeded variable initialization
power: supply: surface-charger: Make symbol 'surface_ac_pm_ops' static
power: supply: surface-battery: Make some symbols static
power: reset: restart-poweroff: Add missing MODULE_DEVICE_TABLE
power: reset: hisi-reboot: add missing MODULE_DEVICE_TABLE
power: supply: s3c_adc_battery: fix possible use-after-free in s3c_adc_bat_remove()
power: supply: generic-adc-battery: fix possible use-after-free in gab_remove()
power: supply: Add AC driver for Surface Aggregator Module
power: supply: Add battery driver for Surface Aggregator Module
power: supply: bq25980: Move props from battery node
power: supply: core: Use true and false for bool variable
power: supply: goldfish: Remove the GOLDFISH dependency
power: reset: ltc2952: make trigger delay configurable
power: supply: cpcap-charger: Simplify bool conversion
power: supply: cpcap-charger: Add usleep to cpcap charger to avoid usb plug bounce
...
Commit dd8088d5a8 ("PM: runtime: Add pm_runtime_resume_and_get to
deal with usage counter") added a new runtime-PM API function without
updating the documentation in runtime_pm.rst.
Add the missing documentation.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Fixes: dd8088d5a8 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull documentation updates from Jonathan Corbet:
"It has been a relatively quiet cycle in docsland.
- As promised, the minimum Sphinx version to build the docs is now
1.7, and we have dropped support for Python 2 entirely. That
allowed the removal of a bunch of compatibility code.
- A set of treewide warning fixups from Mauro that I applied after it
became clear nobody else was going to deal with them.
- The automarkup mechanism can now create cross-references from
relative paths to RST files.
- More translations, typo fixes, and warning fixes"
* tag 'docs-5.12' of git://git.lwn.net/linux: (75 commits)
docs: kernel-hacking: be more civil
docs: Remove the Microsoft rhetoric
Documentation/admin-guide: kernel-parameters: Update nohlt section
doc/admin-guide: fix spelling mistake: "perfomance" -> "performance"
docs: Document cross-referencing using relative path
docs: Enable usage of relative paths to docs on automarkup
docs: thermal: fix spelling mistakes
Documentation: admin-guide: Update kvm/xen config option
docs: Make syscalls' helpers naming consistent
coding-style.rst: Avoid comma statements
Documentation: /proc/loadavg: add 3 more field descriptions
Documentation/submitting-patches: Add blurb about backtraces in commit messages
Docs: drop Python 2 support
Move our minimum Sphinx version to 1.7
Documentation: input: define ABS_PRESSURE/ABS_MT_PRESSURE resolution as grams
scripts/kernel-doc: add internal hyperlink to DOC: sections
Update Documentation/admin-guide/sysctl/fs.rst
docs: Update DTB format references
docs: zh_CN: add iio index.rst translation
docs/zh_CN: add iio ep93xx_adc.rst translation
...
* powercap:
powercap: intel_rapl: Use topology interface in rapl_init_domains()
powercap: intel_rapl: Use topology interface in rapl_add_package()
powercap/intel_rapl: add support for AlderLake Mobile
powercap/drivers/dtpm: Fix size of object being allocated
powercap/drivers/dtpm: Fix an IS_ERR() vs NULL check
powercap/drivers/dtpm: Fix some missing unlock bugs
powercap/drivers/dtpm: Fix a double shift bug
powercap/drivers/dtpm: Fix __udivdi3 and __aeabi_uldivmod unresolved symbols
powercap/drivers/dtpm: Add CPU energy model based support
powercap/drivers/dtpm: Add API for dynamic thermal power management
Documentation/powercap/dtpm: Add documentation for dtpm
units: Add Watt units
* pm-misc:
PM: Kconfig: remove unneeded "default n" options
PM: EM: update Kconfig description and drop "default n" option
Replace the lkml.org links with lore to better use a single source
that's more likely to stay available long-term.
Done by bash script:
cvt_lkml_to_lore ()
{
tmpfile=$(mktemp ./.cvt_links.XXXXXXX)
header=$(echo $1 | sed 's@/lkml/@/lkml/headers/@')
wget -qO - $header > $tmpfile
if [[ $? == 0 ]] ; then
link=$(grep -i '^Message-Id:' $tmpfile | head -1 | \
sed -r -e 's/^\s*Message-Id:\s*<\s*//' -e 's/\s*>\s*$//' -e 's@^@https://lore.kernel.org/r/@')
# echo "testlink: $link"
if [ -n "$link" ] ; then
wget -qO - $link > /dev/null
if [[ $? == 0 ]] ; then
echo $link
fi
fi
fi
rm -f $tmpfile
}
git grep -P -o "\bhttps?://(?:www.)?lkml.org/lkml[\/\w]+" $@ |
while read line ; do
echo $line
file=$(echo $line | cut -f1 -d':')
link=$(echo $line | cut -f2- -d':')
newlink=$(cvt_lkml_to_lore $link)
if [[ -n "$newlink" ]] ; then
sed -i -e "s#\b$link\b#$newlink#" $file
fi
done
Link: https://lore.kernel.org/patchwork/patch/1265849/#1462688
Signed-off-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/77cdb7f32cfb087955bfc3600b86c40bed5d4104.camel@perches.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The dynamic thermal and power management is a technique to dynamically
adjust the power consumption of different devices in order to ensure a
global thermal constraint.
An userspace daemon is usually monitoring the temperature and the
power to take immediate action on the device.
The DTPM framework provides an unified API to userspace to act on the
power.
Document this framework.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Update description and meaning of a new flag, which indicates the type of
power scale used for a registered Energy Model (EM) device.
Reviewed-by: Quentin Perret <qperret@google.com>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The Energy Model (EM) can store power values in milli-Watts or in abstract
scale. This might cause issues in the subsystems which use the EM for
estimating the device power, such as:
- mixing of different scales in a subsystem which uses multiple
(cooling) devices (e.g. thermal Intelligent Power Allocation (IPA))
- assuming that energy [milli-Joules] can be derived from the EM power
values which might not be possible since the power scale doesn't have
to be in milli-Watts
To avoid misconfiguration add the requisite documentation to the EM and
related subsystems: EAS and IPA.
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PCI devices support two variants of the D3 power state: D3hot (main power
present) D3cold (main power removed). Previously struct pci_dev contained:
unsigned int d3_delay; /* D3->D0 transition time in ms */
unsigned int d3cold_delay; /* D3cold->D0 transition time in ms */
"d3_delay" refers specifically to the D3hot state. Rename it to
"d3hot_delay" to avoid ambiguity and align with the ACPI "_DSM for
Specifying Device Readiness Durations" in the PCI Firmware spec r3.2,
sec 4.6.9.
There is no change to the functionality.
Link: https://lore.kernel.org/r/20200730210848.1578826-1-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* pm-sleep:
PM: sleep: spread "const char *" correctness
PM: hibernate: fix white space in a few places
freezer: Add unsafe version of freezable_schedule_timeout_interruptible() for NFS
PM: sleep: core: Emit changed uevent on wakeup_sysfs_add/remove
* pm-domains:
PM: domains: Restore comment indentation for generic_pm_domain.child_links
PM: domains: Fix up terminology with parent/child
* powercap:
powercap: Add Power Limit4 support
powercap: idle_inject: Replace play_idle() with play_idle_precise() in comments
powercap: intel_rapl: add support for Sapphire Rapids
* pm-tools:
pm-graph v5.7 - important s2idle fixes
cpupower: Replace HTTP links with HTTPS ones
cpupower: Fix NULL but dereferenced coccicheck errors
cpupower: Fix comparing pointer to 0 coccicheck warns
Modern Intel Mobile platforms support power limit4 (PL4), which is
the SoC package level maximum power limit (in Watts). It can be used
to preemptively limits potential SoC power to prevent power spikes
from tripping the power adapter and battery over-current protection.
This patch enables this feature by exposing package level peak power
capping control to userspace via RAPL sysfs interface. With this,
application like DTPF can modify PL4 power limit, the similar way
of other package power limit (PL1).
As this feature is not tested on previous generations, here it is
enabled only for the platform that has been verified to work,
for safety concerns.
Signed-off-by: Sumeet Pawnikar <sumeet.r.pawnikar@intel.com>
Co-developed-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull power management updates from Rafael Wysocki:
"These rework the system-wide PM driver flags, make runtime switching
of cpuidle governors easier, improve the user space hibernation
interface code, add intel-speed-select interface documentation, add
more debug messages to the ACPI code handling suspend to idle, update
the cpufreq core and drivers, fix a minor issue in the cpuidle core
and update two cpuidle drivers, improve the PM-runtime framework,
update the Intel RAPL power capping driver, update devfreq core and
drivers, and clean up the cpupower utility.
Specifics:
- Rework the system-wide PM driver flags to make them easier to
understand and use and update their documentation (Rafael Wysocki,
Alan Stern).
- Allow cpuidle governors to be switched at run time regardless of
the kernel configuration and update the related documentation
accordingly (Hanjun Guo).
- Improve the resume device handling in the user space hibernarion
interface code (Domenico Andreoli).
- Document the intel-speed-select sysfs interface (Srinivas
Pandruvada).
- Make the ACPI code handing suspend to idle print more debug
messages to help diagnose issues with it (Rafael Wysocki).
- Fix a helper routine in the cpufreq core and correct a typo in the
struct cpufreq_driver kerneldoc comment (Rafael Wysocki, Wang
Wenhu).
- Update cpufreq drivers:
- Make the intel_pstate driver start in the passive mode by
default on systems without HWP (Rafael Wysocki).
- Add i.MX7ULP support to the imx-cpufreq-dt driver and add
i.MX7ULP to the cpufreq-dt-platdev blacklist (Peng Fan).
- Convert the qoriq cpufreq driver to a platform one, make the
platform code create a suitable device object for it and add
platform dependencies to it (Mian Yousaf Kaukab, Geert
Uytterhoeven).
- Fix wrong compatible binding in the qcom driver (Ansuel Smith).
- Build the omap driver by default for ARCH_OMAP2PLUS (Anders
Roxell).
- Add r8a7742 SoC support to the dt cpufreq driver (Lad
Prabhakar).
- Update cpuidle core and drivers:
- Fix three reference count leaks in error code paths in the
cpuidle core (Qiushi Wu).
- Convert Qualcomm SPM to a generic cpuidle driver (Stephan
Gerhold).
- Fix up the execution order when entering a domain idle state in
the PSCI driver (Ulf Hansson).
- Fix a reference counting issue related to clock management and
clean up two oddities in the PM-runtime framework (Rafael Wysocki,
Andy Shevchenko).
- Add ElkhartLake support to the Intel RAPL power capping driver and
remove an unused local MSR definition from it (Jacob Pan, Sumeet
Pawnikar).
- Update devfreq core and drivers:
- Replace strncpy() with strscpy() in the devfreq core and use
lockdep asserts instead of manual checks for a locked mutex in
it (Dmitry Osipenko, Krzysztof Kozlowski).
- Add a generic imx bus scaling driver and make it register an
interconnect device (Leonard Crestez, Gustavo A. R. Silva).
- Make the cpufreq notifier in the tegra30 driver take boosting
into account and delete an unuseful error message from that
driver (Dmitry Osipenko, Markus Elfring).
- Remove unneeded semicolon from the cpupower code (Zou Wei)"
* tag 'pm-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (51 commits)
cpuidle: Fix three reference count leaks
PM: runtime: Replace pm_runtime_callbacks_present()
PM / devfreq: Use lockdep asserts instead of manual checks for locked mutex
PM / devfreq: imx-bus: Fix inconsistent IS_ERR and PTR_ERR
PM / devfreq: Replace strncpy with strscpy
PM / devfreq: imx: Register interconnect device
PM / devfreq: Add generic imx bus scaling driver
PM / devfreq: tegra30: Delete an error message in tegra_devfreq_probe()
PM / devfreq: tegra30: Make CPUFreq notifier to take into account boosting
PM: hibernate: Restrict writes to the resume device
PM: runtime: clk: Fix clk_pm_runtime_get() error path
cpuidle: Convert Qualcomm SPM driver to a generic CPUidle driver
ACPI: EC: PM: s2idle: Extend GPE dispatching debug message
ACPI: PM: s2idle: Print type of wakeup debug messages
powercap: RAPL: remove unused local MSR define
PM: runtime: Make clear what we do when conditions are wrong in rpm_suspend()
Documentation: admin-guide: pm: Document intel-speed-select
PM: hibernate: Split off snapshot dev option
PM: hibernate: Incorporate concurrency handling
Documentation: ABI: make current_governer_ro as a candidate for removal
...
The single user could have called freeze_secondary_cpus() directly.
Since this function was a source of confusion, remove it as it's
just a pointless wrapper.
While at it, rename enable_nonboot_cpus() to thaw_secondary_cpus() to
preserve the naming symmetry.
Done automatically via:
git grep -l enable_nonboot_cpus | xargs sed -i 's/enable_nonboot_cpus/thaw_secondary_cpus/g'
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Link: https://lkml.kernel.org/r/20200430114004.17477-1-qais.yousef@arm.com
Update the documentation of the driver flags for system-wide power
management to reflect the current code flows and be more consistent.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The name of dev_pm_may_skip_resume() may be easily confused with the
power.may_skip_resume flag which is not checked by that function, so
rename the former as dev_pm_skip_resume().
No functional impact.
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
