While attaching/detaching a device to a PM domain (genpd) with
GENPD_FLAG_CPU_DOMAIN set, genpd iterates the cpu_possible_mask to
check whether or not the device corresponds to a CPU. This iteration
is done while holding the genpd's lock, which is unnecessary.
Avoid the locking by restructuring the corresponding code a bit.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Both genpd_alloc_dev_data() and genpd_add_device(), that are internal
genpd functions, allow a struct gpd_timing_data *td to be passed as an
in-parameter. However, as NULL is always passed, let's just drop the
in-parameter altogether.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When genpd fails to attach a device to one of its multiple PM domains,
we end up calling driver_deferred_probe_check_state() for the recently
allocated virtual device. This is incorrect, as it's the base device
that is being probed.
Fix this by passing along the base device to __genpd_dev_pm_attach()
and use that instead.
Fixes: e01afc3250 ("PM / Domains: Stop deferring probe at the end of initcall")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If a call to dev_pm_domain_attach() succeeds to attach a device to its
single PM domain, the important point is to prevent subsequent
dev_pm_domain_attach_by_name|id() calls from failing. That is done by
checking the dev->pm_domain pointer and then returning -EEXIST, rather
than continuing to call genpd_dev_pm_attach_by_id|name().
For this reason, enable genpd_dev_pm_attach_by_id|name() to be used for
single PM domains too. This simplifies future users, so they only need
to use dev_pm_domain_attach_by_id|name() instead of having to combine
it with dev_pm_domain_attach().
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
A genpd provider that uses the ->attach_dev() callback to look up
resources for a device fails to do so when the device has multiple
PM domains attached. That is because when genpd invokes the
->attach_dev() callback, it passes the allocated virtual device as
the in-parameter.
To address this problem, simply assign the dev->of_node for the
virtual device, based upon the original device's OF node.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It's not correct to call kfree(dev) when device_register(dev) has failed.
Fix this by calling put_device(dev) instead.
Fixes: 3c095f32a9 ("PM / Domains: Add support for multi PM domains per device to genpd")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
WARN_ON() already contains an unlikely(), so it's not necessary to use
unlikely.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
After some preceding changes, PM domains managed by genpd may contain
CPU devices, so idle state residency values should be taken into
account during the state selection process. [The residency value is
the minimum amount of time to be spent by a CPU (or a group of CPUs)
in an idle state in order to save more energy than could be saved
by picking up a shallower idle state.]
For this purpose, add a new genpd governor, pm_domain_cpu_gov, to be
used for selecting idle states of PM domains with CPU devices attached
either directly or through subdomains.
The new governor computes the minimum expected idle duration for all
online CPUs attached to a PM domain and its subdomains. Next, it
finds the deepest idle state whose target residency is within the
expected idle duration and selects it as the target idle state of
the domain.
It should be noted that the minimum expected idle duration computation
is based on the closest timer event information stored in the per-CPU
variables cpuidle_devices for all of the CPUs in the domain. That
needs to be revisited in future, as obviously there are other reasons
why a CPU may be woken up from idle.
Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
To enable a CPU device to be attached to a PM domain managed by genpd,
make a few changes to it for convenience.
To be able to quickly find out what CPUs are attached to a genpd,
which typically becomes useful from a genpd governor as subsequent
changes are about to show, add a cpumask to struct generic_pm_domain
to be updated when a CPU device gets attached to the genpd containing
that cpumask. Also, propagate the cpumask changes upwards in the
domain hierarchy to the master PM domains. This way, the cpumask for
a genpd hierarchically reflects all CPUs attached to the topology
below it.
Finally, make this an opt-in feature, to avoid having to manage CPUs
and the cpumask for a genpd that don't need it. To that end, add
a new genpd configuration bit, GENPD_FLAG_CPU_DOMAIN.
Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add a data pointer to the genpd_power_state struct, to allow a genpd
backend driver to store per-state specific data. To introduce the
pointer, change the way genpd deals with freeing of the corresponding
allocated data.
More precisely, clarify the responsibility of whom that shall free the
data, by adding a ->free_states() callback to the generic_pm_domain
structure. The one allocating the data will be expected to set the
callback, to allow genpd to invoke it from genpd_remove().
Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Lockdep warns that prepare_lock and genpd->mlock can cause a deadlock
the deadlock scenario is like following:
First thread is probing cs2000
cs2000_probe()
clk_register()
__clk_core_init()
clk_prepare_lock() ----> acquires prepare_lock
cs2000_recalc_rate()
i2c_smbus_read_byte_data()
rcar_i2c_master_xfer()
dma_request_chan()
rcar_dmac_of_xlate()
rcar_dmac_alloc_chan_resources()
pm_runtime_get_sync()
__pm_runtime_resume()
rpm_resume()
rpm_callback()
genpd_runtime_resume() ----> acquires genpd->mlock
Second thread is attaching any device to the same PM domain
genpd_add_device()
genpd_lock() ----> acquires genpd->mlock
cpg_mssr_attach_dev()
of_clk_get_from_provider()
__of_clk_get_from_provider()
__clk_create_clk()
clk_prepare_lock() ----> acquires prepare_lock
Since currently no PM provider access genpd's critical section
in .attach_dev, and .detach_dev callbacks, so there is no need to protect
these two callbacks with genpd->mlock.
This patch avoids a potential deadlock by moving out .attach_dev and .detach_dev
from genpd->mlock, so that genpd->mlock won't be held when prepare_lock is acquired
in .attach_dev and .detach_dev
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Fix registration of new cpuidle governors partially broken during
the 5.0 development cycle by mistake (Rafael Wysocki).
- Avoid integer overflows in the menu cpuidle governor by making
it discard the overflowing data points upfront (Rafael Wysocki).
- Fix minor mistake in the recent update of the iowait boost
computation in the intel_pstate driver (Rafael Wysocki).
- Drop incorrect __init annotation from one function in the pxa2xx
cpufreq driver (Arnd Bergmann).
- Fix the operating performance points (OPP) framework
initialization for devices in multiple power domains if
only one of them is scalable (Rajendra Nayak).
- Fix mistake in dev_pm_opp_set_rate() which causes it to skip
updating the performance state if the new frequency is the same
as the old one (Viresh Kumar).
- Rework the cancellation of wakeup source timers to avoid
potential issues with it and do some cleanups unlocked by
that change (Viresh Kumar, Rafael Wysocki).
- Clean up the code computing the active/suspended time of devices
in the PM-runtime framework after recent changes (Ulf Hansson).
- Make the power management infrastructure code use pr_fmt()
consistently (Joe Perches).
- Clean up the generic power domains (genpd) framework somewhat
(Aisheng Dong).
- Improve kerneldoc comments for two functions in the cpufreq core
(Rafael Wysocki).
- Fix typo in a PM QoS file description comment (Aisheng Dong).
- Update the handling of CPU boost frequencies in the cpupower
utility (Abhishek Goel).
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Merge tag 'pm-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more power management updates from Rafael Wysocki:
"These are mostly fixes and cleanups on top of the previously merged
power management material for 5.1-rc1 with one cpupower utility update
that wasn't pushed earlier due to unfortunate timing.
Specifics:
- Fix registration of new cpuidle governors partially broken during
the 5.0 development cycle by mistake (Rafael Wysocki).
- Avoid integer overflows in the menu cpuidle governor by making it
discard the overflowing data points upfront (Rafael Wysocki).
- Fix minor mistake in the recent update of the iowait boost
computation in the intel_pstate driver (Rafael Wysocki).
- Drop incorrect __init annotation from one function in the pxa2xx
cpufreq driver (Arnd Bergmann).
- Fix the operating performance points (OPP) framework initialization
for devices in multiple power domains if only one of them is
scalable (Rajendra Nayak).
- Fix mistake in dev_pm_opp_set_rate() which causes it to skip
updating the performance state if the new frequency is the same as
the old one (Viresh Kumar).
- Rework the cancellation of wakeup source timers to avoid potential
issues with it and do some cleanups unlocked by that change (Viresh
Kumar, Rafael Wysocki).
- Clean up the code computing the active/suspended time of devices in
the PM-runtime framework after recent changes (Ulf Hansson).
- Make the power management infrastructure code use pr_fmt()
consistently (Joe Perches).
- Clean up the generic power domains (genpd) framework somewhat
(Aisheng Dong).
- Improve kerneldoc comments for two functions in the cpufreq core
(Rafael Wysocki).
- Fix typo in a PM QoS file description comment (Aisheng Dong).
- Update the handling of CPU boost frequencies in the cpupower
utility (Abhishek Goel)"
* tag 'pm-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpuidle: governor: Add new governors to cpuidle_governors again
cpufreq: intel_pstate: Fix up iowait_boost computation
PM / OPP: Update performance state when freq == old_freq
PM / wakeup: Drop wakeup_source_drop()
PM / wakeup: Rework wakeup source timer cancellation
PM / domains: Remove one unnecessary blank line
PM / Domains: Return early for all errors in _genpd_power_off()
PM / Domains: Improve warn for multiple states but no governor
OPP: Fix handling of multiple power domains
PM / QoS: Fix typo in file description
cpufreq: pxa2xx: remove incorrect __init annotation
PM-runtime: Call pm_runtime_active|suspended_time() from sysfs
PM-runtime: Consolidate code to get active/suspended time
PM: Add and use pr_fmt()
cpufreq: Improve kerneldoc comments for cpufreq_cpu_get/put()
cpuidle: menu: Avoid overflows when computing variance
tools/power/cpupower: Display boost frequency separately
* pm-domains:
PM / domains: Remove one unnecessary blank line
PM / Domains: Return early for all errors in _genpd_power_off()
PM / Domains: Improve warn for multiple states but no governor
After commit d856f39ac1cc ("PM / wakeup: Rework wakeup source timer
cancellation") wakeup_source_drop() is a trivial wrapper around
__pm_relax() and it has no users except for wakeup_source_destroy()
and wakeup_source_trash() which also has no users, so drop it along
with the latter and make wakeup_source_destroy() call __pm_relax()
directly.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
If wakeup_source_add() is called right after wakeup_source_remove()
for the same wakeup source, timer_setup() may be called for a
potentially scheduled timer which is incorrect.
To avoid that, move the wakeup source timer cancellation from
wakeup_source_drop() to wakeup_source_remove().
Moreover, make wakeup_source_remove() clear the timer function after
canceling the timer to let wakeup_source_not_registered() treat
unregistered wakeup sources in the same way as the ones that have
never been registered.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
[ rjw: Subject, changelog, merged two patches together ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It is strange to only return early for -EBUSY state and left other
errors to be still measured execution time.
As for error cases, the elapsed_ns computed actually is not quite
accurate and meaningful for governor to use. So let's simply return
for all error cases.
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It's possible a PM domain defines only one state and it does not need
a governor to work. For such case, a warning actually is not necessary.
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Fix a typo in the file description comment.
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Avoid the open-coding of the accounted time acquisition in
runtime_active|suspend_time_show() and make them call
pm_runtime_active|suspended_time() instead.
Note that this change also indirectly avoids holding dev->power.lock
around the do_div() computation and the sprintf() call which is an
additional improvement.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In a step to consolidate the code for fetching the PM-runtime
active/suspended time for a device, add a common function for that
and make the existing pm_runtime_suspended_time() call it.
Also add a corresponding pm_runtime_active_time() calling the new
common function.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Changelog, function rename ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Prefix all printk/pr_<level> messages with "PM: " to make the
logging a bit more consistent.
Miscellanea:
o Convert a few printks to pr_<level>
o Whitespace to align to open parentheses
o Remove embedded "PM: " from pr_debugs as pr_fmt adds it
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Here is the big driver core patchset for 5.1-rc1
More patches than "normal" here this merge window, due to some work in
the driver core by Alexander Duyck to rework the async probe
functionality to work better for a number of devices, and independant
work from Rafael for the device link functionality to make it work
"correctly".
Also in here is:
- lots of BUS_ATTR() removals, the macro is about to go away
- firmware test fixups
- ihex fixups and simplification
- component additions (also includes i915 patches)
- lots of minor coding style fixups and cleanups.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the big driver core patchset for 5.1-rc1
More patches than "normal" here this merge window, due to some work in
the driver core by Alexander Duyck to rework the async probe
functionality to work better for a number of devices, and independant
work from Rafael for the device link functionality to make it work
"correctly".
Also in here is:
- lots of BUS_ATTR() removals, the macro is about to go away
- firmware test fixups
- ihex fixups and simplification
- component additions (also includes i915 patches)
- lots of minor coding style fixups and cleanups.
All of these have been in linux-next for a while with no reported
issues"
* tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (65 commits)
driver core: platform: remove misleading err_alloc label
platform: set of_node in platform_device_register_full()
firmware: hardcode the debug message for -ENOENT
driver core: Add missing description of new struct device_link field
driver core: Fix PM-runtime for links added during consumer probe
drivers/component: kerneldoc polish
async: Add cmdline option to specify drivers to be async probed
driver core: Fix possible supplier PM-usage counter imbalance
PM-runtime: Fix __pm_runtime_set_status() race with runtime resume
driver: platform: Support parsing GpioInt 0 in platform_get_irq()
selftests: firmware: fix verify_reqs() return value
Revert "selftests: firmware: remove use of non-standard diff -Z option"
Revert "selftests: firmware: add CONFIG_FW_LOADER_USER_HELPER_FALLBACK to config"
device: Fix comment for driver_data in struct device
kernfs: Allocating memory for kernfs_iattrs with kmem_cache.
sysfs: remove unused include of kernfs-internal.h
driver core: Postpone DMA tear-down until after devres release
driver core: Document limitation related to DL_FLAG_RPM_ACTIVE
PM-runtime: Take suppliers into account in __pm_runtime_set_status()
device.h: Add __cold to dev_<level> logging functions
...
* pm-core:
PM / core: Add support to skip power management in device/driver model
PM / suspend: Print debug messages for device using direct-complete
PM-runtime: update time accounting only when enabled
PM-runtime: Switch accounting over to ktime_get_mono_fast_ns()
PM-runtime: Optimize pm_runtime_autosuspend_expiration()
PM-runtime: Replace jiffies-based accounting with ktime-based accounting
PM-runtime: update accounting_timestamp on enable
PM: clock_ops: fix missing clk_prepare() return value check
drm/i915: Move on the new pm runtime interface
PM-runtime: Add new interface to get accounted time
* pm-sleep:
PM / wakeup: fix kerneldoc comment for pm_wakeup_dev_event()
* pm-qos:
PM: QoS: no need to check return value of debugfs_create functions
* pm-domains:
PM / Domains: Mark "name" const in dev_pm_domain_attach_by_name()
PM / Domains: Mark "name" const in genpd_dev_pm_attach_by_name()
PM: domains: no need to check return value of debugfs_create functions
* pm-em:
PM / EM: Expose the Energy Model in debugfs
When rpm_resume() desactivates the autosuspend timer, it should only
try to cancel hrtimer but not wait for the handler to finish, because
both rpm_resume() and pm_suspend_timer_fn() take the power.lock.
A deadlock is possible as follows:
CPU0 CPU1
rpm_resume()
spin_lock_irqsave
pm_suspend_timer_fn()
spin_lock_irqsave
pm_runtime_deactivate_timer()
hrtimer_cancel()
It is sufficient to call hrtimer_try_to_cancel() from
pm_runtime_deactivate_timer(), because dev->power.timer_expires
reset to 0 by it, so use that function instead of hrtimer_cancel().
Fixes: 8234f6734c ("PM-runtime: Switch autosuspend over to using hrtimers")
Reported-by: Sunzhaosheng Sun(Zhaosheng) <sunzhaosheng@hisilicon.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit 4c06c4e6cf ("driver core: Fix possible supplier PM-usage
counter imbalance") introduced a regression that causes suppliers
to be suspended prematurely for device links added during consumer
driver probe if the initial PM-runtime status of the consumer is
"suspended" and the consumer is resumed after adding the link and
before pm_runtime_put_suppliers() is called. In that case,
pm_runtime_put_suppliers() will drop the rpm_active refcount for
the link by one and (since rpm_active is equal to two after the
preceding consumer resume) the supplier's PM-runtime usage counter
will be decremented, which may cause the supplier to suspend even
though the consumer's PM-runtime status is "active".
For this reason, partially revert commit 4c06c4e6cf as the problem
it tried to fix needs to be addressed somewhat differently, and
change pm_runtime_get_suppliers() and pm_runtime_put_suppliers() so
that the latter only drops rpm_active references acquired by the
former. [This requires adding a new field to struct device_link,
but I coulnd't find a cleaner way to address the issue that would
work in all cases.]
This causes pm_runtime_put_suppliers() to effectively ignore device
links added during consumer probe, so device_link_add() doesn't need
to worry about ensuring that suppliers will remain active after
pm_runtime_put_suppliers() for links created with DL_FLAG_RPM_ACTIVE
set and it only needs to bump up rpm_active by one for those links,
so pm_runtime_active_link() is not necessary any more.
Fixes: 4c06c4e6cf ("driver core: Fix possible supplier PM-usage counter imbalance")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All device objects in the driver model contain fields that control the
handling of various power management activities. However, it's not
always useful. There are few instances where pseudo devices are added
to the model just to take advantage of many other features like
kobjects, udev events, and so on. One such example is cpu devices and
their caches.
The sysfs for the cpu caches are managed by adding devices with cpu
as the parent in cpu_device_create() when secondary cpu is brought
online. Generally when the secondary CPUs are hotplugged back in as part
of resume from suspend-to-ram, we call cpu_device_create() from the cpu
hotplug state machine while the cpu device associated with that CPU is
not yet ready to be resumed as the device_resume() call happens bit
later. It's not really needed to set the flag is_prepared for cpu
devices as they are mostly pseudo device and hotplug framework deals
with state machine and not managed through the cpu device.
This often results in annoying warning when resuming:
Enabling non-boot CPUs ...
CPU1: Booted secondary processor
cache: parent cpu1 should not be sleeping
CPU1 is up
CPU2: Booted secondary processor
cache: parent cpu2 should not be sleeping
CPU2 is up
.... and so on.
So in order to fix these kind of errors, we could just completely avoid
doing any power management related initialisations and operations if
they are not used by these devices.
Add no_pm flags to indicate that the device doesn't require any sort of
PM activities and all of them can be completely skipped. We can use the
same flag to also avoid adding not used *power* sysfs entries for these
devices. For now, lets use this for cpu cache devices.
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
As of the patch ("PM / Domains: Mark "name" const in
genpd_dev_pm_attach_by_name()") it's clear that the name in
dev_pm_domain_attach_by_name() can be const. Mark it as so. This
allows drivers to pass in a name that was declared "const" in a
driver.
Fixes: 27dceb81f4 ("PM / Domains: Introduce dev_pm_domain_attach_by_name()")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The genpd_dev_pm_attach_by_name() simply takes the name and passes it
to of_property_match_string() where the argument is "const char *".
Adding a const here allows a later patch to add a const to
dev_pm_domain_attach_by_name() which allows drivers to pass in a name
that was declared "const" in a driver.
Fixes: 5d6be70add ("PM / Domains: Introduce option to attach a device by name to genpd")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Devices using the direct-complete optimization are not present it
debug messages printed by the core device suspend and resume code,
which sometimes makes it difficult to diagnose problems related to
them, so add debug messages for those devices.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If a stateless device link to a certain supplier with
DL_FLAG_PM_RUNTIME set in the flags is added and then removed by the
consumer driver's probe callback, the supplier's PM-runtime usage
counter will be nonzero after that which effectively causes the
supplier to remain "always on" going forward.
Namely, device_link_add() called to add the link invokes
device_link_rpm_prepare() which notices that the consumer driver is
probing, so it increments the supplier's PM-runtime usage counter
with the assumption that the link will stay around until
pm_runtime_put_suppliers() is called by driver_probe_device(),
but if the link goes away before that point, the supplier's
PM-runtime usage counter will remain nonzero.
To prevent that from happening, first rework pm_runtime_get_suppliers()
and pm_runtime_put_suppliers() to use the rpm_active refounts of device
links and make the latter only drop rpm_active and the supplier's
PM-runtime usage counter for each link by one, unless rpm_active is
one already for it. Next, modify device_link_add() to bump up the
new link's rpm_active refcount and the suppliers PM-runtime usage
counter by two, to prevent pm_runtime_put_suppliers(), if it is
called subsequently, from suspending the supplier prematurely (in
case its PM-runtime usage counter goes down to 0 in there).
Due to the way rpm_put_suppliers() works, this change does not
affect runtime suspend of the consumer ends of new device links (or,
generally, device links for which DL_FLAG_PM_RUNTIME has just been
set).
Fixes: e2f3cd831a ("driver core: Fix handling of runtime PM flags in device_link_add()")
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 4080ab0830 ("PM-runtime: Take suppliers into account in
__pm_runtime_set_status()") introduced a race condition that may
trigger if __pm_runtime_set_status() is used incorrectly (that is,
if it is called when PM-runtime is enabled for the target device
and working).
In that case, if the original PM-runtime status of the device is
RPM_SUSPENDED, a runtime resume of the device may occur after
__pm_runtime_set_status() has dropped its power.lock spinlock
and before deactivating its suppliers, so the suppliers may be
deactivated while the device is PM-runtime-active which may lead
to functional issues.
To avoid that, modify __pm_runtime_set_status() to check whether
or not PM-runtime is enabled for the device before activating its
suppliers (if the new status is RPM_ACTIVE) and either return an
error if that's the case or increment the device's disable_depth
counter to prevent PM-runtime from being enabled for it while
the remaining part of the function is running (disable_depth is
then decremented on the way out).
Fixes: 4080ab0830 ("PM-runtime: Take suppliers into account in __pm_runtime_set_status()")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the target device has any suppliers, as reflected by device links
to them, __pm_runtime_set_status() does not take them into account,
which is not consistent with the other parts of the PM-runtime
framework and may lead to programming mistakes.
Modify __pm_runtime_set_status() to take suppliers into account by
activating them upfront if the new status is RPM_ACTIVE and
deactivating them on exit if the new status is RPM_SUSPENDED.
If the activation of one of the suppliers fails, the new status
will be RPM_SUSPENDED and the (remaining) suppliers will be
deactivated on exit (the child count of the device's parent
will be dropped too then).
Of course, adding device links locking to __pm_runtime_set_status()
means that it cannot be run fron interrupt context, so make it use
spin_lock_irq() and spin_unlock_irq() instead of spin_lock_irqsave()
and spin_unlock_irqrestore(), respectively.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Update the accounting_timestamp field only when PM runtime is enabled
and don't forget to account the last state before disabling it.
Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Minor cleanups ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Similar to what happened whith autosuspend, a deadlock has been
reported with PM-runtime accounting in the call path:
change_clocksource
...
write_seqcount_begin
...
timekeeping_update
...
sh_cmt_clocksource_enable
...
rpm_resume
update_pm_runtime_accounting
ktime_get
do
read_seqcount_begin
while read_seqcount_retry
....
write_seqcount_end
Make PM-runtime accounting use ktime_get_mono_fast_ns() to avoid this
problem.
With ktime_get_mono_fast_ns(), the timestamp is not guaranteed to be
monotonic across an update of timekeeping and as a result time can go
backward. Add a test to skip accounting for such situation which should
stay exceptional.
Fixes: a08c2a5a31 ("PM-runtime: Replace jiffies-based accounting with ktime-based accounting")
Reported-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Subject, changelog, comment cleanup ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
pm_runtime_autosuspend_expiration calls ktime_get_mono_fast_ns()
even when its returned value may be unused. Therefore get the
current time later and remove gotos while there.
Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Calling rpm_put_suppliers() from pm_runtime_drop_link() is excessive
as it affects all suppliers of the consumer device and not just the
one pointed to by the device link being dropped. Worst case it may
cause the consumer device to stop working unexpectedly. Moreover, in
principle it is racy with respect to runtime PM of the consumer
device.
To avoid these problems drop runtime PM references on the particular
supplier pointed to by the link in question only and do that after
the link has been dropped from the consumer device's list of links to
suppliers, which is in device_link_free().
Fixes: a0504aecba ("PM / runtime: Drop usage count for suppliers at device link removal")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After commit ead18c23c2 ("driver core: Introduce device links
reference counting"), if there is a link between the given supplier
and the given consumer already, device_link_add() will refcount it
and return it unconditionally without updating its flags. It is
possible, however, that the second (or any subsequent) caller of
device_link_add() for the same consumer-supplier pair will pass
DL_FLAG_PM_RUNTIME, possibly along with DL_FLAG_RPM_ACTIVE, in flags
to it and the existing link may not behave as expected then.
First, if DL_FLAG_PM_RUNTIME is not set in the existing link's flags
at all, it needs to be set like during the original initialization of
the link.
Second, if DL_FLAG_RPM_ACTIVE is passed to device_link_add() in flags
(in addition to DL_FLAG_PM_RUNTIME), the existing link should to be
updated to reflect the "active" runtime PM configuration of the
consumer-supplier pair and extra care must be taken here to avoid
possible destructive races with runtime PM of the consumer.
To that end, redefine the rpm_active field in struct device_link
as a refcount, initialize it to 1 and make rpm_resume() (for the
consumer) and device_link_add() increment it whenever they acquire
a runtime PM reference on the supplier device. Accordingly, make
rpm_suspend() (for the consumer) and pm_runtime_clean_up_links()
decrement it and drop runtime PM references to the supplier
device in a loop until rpm_active becones 1 again.
Fixes: ead18c23c2 ("driver core: Introduce device links reference counting")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the device specific version of the async_schedule commands to defer
various tasks related to power management. By doing this we should see a
slight improvement in performance as any device that is sensitive to
latency/locality in the setup will now be initializing on the node closest
to the device.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replace jiffies-based accounting for runtime_active_time and
runtime_suspended_time with ktime-based accounting. This makes the
runtime debug counters inline with genpd and other PM subsytems which
use ktime-based accounting.
Timekeeping is initialized before driver_init(). It's only at that time
that PM-runtime can be enabled.
Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
[switch from ktime to raw nsec]
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Initializing accounting_timestamp to something different from 0 during
pm_runtime_init() doesn't make sense and puts an artificial ordering
constraint between timekeeping_init() and pm_runtime_init().
PM-runtime should start time accounting only when it is enabled and
discard the period when disabled.
Set accounting_timestamp to now when enabling PM-runtime.
Suggested-by: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
A deadlock has been seen when swicthing clocksources which use
PM-runtime. The call path is:
change_clocksource
...
write_seqcount_begin
...
timekeeping_update
...
sh_cmt_clocksource_enable
...
rpm_resume
pm_runtime_mark_last_busy
ktime_get
do
read_seqcount_begin
while read_seqcount_retry
....
write_seqcount_end
Although we should be safe because we haven't yet changed the
clocksource at that time, we can't do that because of seqcount
protection.
Use ktime_get_mono_fast_ns() instead which is lock safe for such
cases.
With ktime_get_mono_fast_ns, the timestamp is not guaranteed to be
monotonic across an update and as a result can goes backward.
According to update_fast_timekeeper() description: "In the worst
case, this can result is a slightly wrong timestamp (a few
nanoseconds)". For PM-runtime autosuspend, this means only that
the suspend decision may be slightly suboptimal.
Fixes: 8234f6734c ("PM-runtime: Switch autosuspend over to using hrtimers")
Reported-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This brings the kernel doc in line with the function signature.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
clk_prepare() can fail, so check its status and if it fails,
issue an error message and change the clock_entry_status to
PCE_STATUS_ERROR.
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
