pm_genpd_remove_subdomain() iterates over domain's master_links list and
removes matching element thus it has to use safe version of list
iteration.
Fixes: f721889ff6 ("PM / Domains: Support for generic I/O PM domains (v8)")
Cc: 3.1+ <stable@vger.kernel.org> # 3.1+
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
genpd_syscore_switch() had two problems:
1. It silently assumed that device, it is being called for, belongs
to generic power domain and used container_of() on its power
domain pointer. Such assumption might not be true always.
2. It iterated over list of generic power domains without holding
gpd_list_lock mutex thus list could have been modified at the same
time.
Usage of genpd_lookup_dev() solves both problems as it is safe a call
for non-generic power domains and uses mutex when iterating.
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently genpd installs its own noirq callbacks, but never calls down
to the driver's corresponding callbacks. Add these calls.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Mark pointer to struct generic_pm_domain const (either passed in
argument or used localy in a function), whenever it is not modifed by
the function itself.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The pm_domain_data (pdd) pointer is set from genpd_alloc_dev_data() and
pdd->dev is guaranteed to be valid. There is no need to check pdd and
pdd->dev in rest of the code as pdd->dev will always be valid for a non
NULL pdd pointer.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Allow generic power domain providers to override the ->xlate() callback
in case the default genpd_xlate_onecell() translation callback is not
good enough.
One potential use-case for this is to allow generic power domains to be
specified by an ID rather than an index.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Driver updates for ARM SoCs.
* Reset subsystem, merged through arm-soc by tradition:
- Make bool drivers explicitly non-modular
- New support for i.MX7 and Arria10 reset controllers
* PATA driver for Palmchip BK371 (acked by Tejun)
* Power domain drivers for i.MX (GPC, GPCv2)
- Moved out of mach-imx for GPC
- Bunch of tweaks, fixes, etc
* PMC support for Tegra186
* SoC detection support for Renesas RZ/G1H and RZ/G1N
* Move Tegra flow controller driver from mach directory to drivers/soc
- (Power management / CPU power driver)
* Misc smaller tweaks for other platforms
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Merge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC driver updates from Olof Johansson:
"Driver updates for ARM SoCs:
Reset subsystem, merged through arm-soc by tradition:
- Make bool drivers explicitly non-modular
- New support for i.MX7 and Arria10 reset controllers
PATA driver for Palmchip BK371 (acked by Tejun)
Power domain drivers for i.MX (GPC, GPCv2)
- Moved out of mach-imx for GPC
- Bunch of tweaks, fixes, etc
PMC support for Tegra186
SoC detection support for Renesas RZ/G1H and RZ/G1N
Move Tegra flow controller driver from mach directory to drivers/soc
- (Power management / CPU power driver)
Misc smaller tweaks for other platforms"
* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (60 commits)
soc: pm-domain: Fix the mangled urls
soc: renesas: rcar-sysc: Add support for R-Car H3 ES2.0
soc: renesas: rcar-sysc: Add support for fixing up power area tables
soc: renesas: Register SoC device early
soc: imx: gpc: add workaround for i.MX6QP to the GPC PD driver
dt-bindings: imx-gpc: add i.MX6 QuadPlus compatible
soc: imx: gpc: add defines for domain index
soc: imx: Add GPCv2 power gating driver
dt-bindings: Add GPCv2 power gating driver
ARM/clk: move the ICST library to drivers/clk
ARM: plat-versatile: remove stale clock header
ARM: keystone: Drop PM domain support for k2g
soc: ti: Add ti_sci_pm_domains driver
dt-bindings: Add TI SCI PM Domains
PM / Domains: Do not check if simple providers have phandle cells
PM / Domains: Add generic data pointer to genpd data struct
soc/tegra: Add initial flowctrl support for Tegra132/210
soc/tegra: flowctrl: Add basic platform driver
soc/tegra: Move Tegra flowctrl driver
ARM: tegra: Remove unnecessary inclusion of flowctrl header
...
There is no reason that a platform genpd driver registered using
of_genpd_add_provider_simple needs to be constrained to having no cells
in the "power-domains" phandle. Currently the genpd framework will fail
if any arguments are passed with for a simple provider but the framework
does not actually care, so remove the check for phandle argument count.
This will allow greater flexibility for genpd providers to use their own
arguments that are passed in the phandle and interpret them however they
see fit.
Acked-by: Kevin Hilman <khilman@baylibre.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
domain-idle-states property may have phandles to idle state bindings
that may not be compatible with idle state definition defined in [1].
Such phandles would just be ignored and not throw and error when read by
the domain core.
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When an IRQ safe device is attached to a no sleep domain, genpd prints a
warning once, as to indicate it is a suboptimal configuration from power
consumption point of view.
However the warning doesn't make sense for an always on domain, since it
anyway remains powered on. Therefore, let's change to not print the warning
for this configuration.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The current code in genpd_sync_power_off(), doesn't care about potential
errors being returned from genpd's ->power_off() callback.
Obviously this behaviour could lead to problems, such as incorrectly
setting the genpd's status to GPD_STATE_POWER_OFF, but also to incorrectly
decrease the subdomain count for the masters, which potentially allows them
to be powered off in the next recursive call to genpd_sync_power_off().
Let's fix this behaviour by bailing out when the ->power_off() callback
returns an error code.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The current way to implement an always on PM domain consists of returning
-EBUSY from the ->power_off() callback. This is a bit different compared to
using the always on genpd governor, which prevents the PM domain from being
powered off via runtime suspend, but not via system suspend.
The approach to return -EBUSY from the ->power_off() callback to support
always on PM domains in genpd is suboptimal. That is because it requires
genpd to follow the regular execution path of the power off sequence, which
ends by invoking the ->power_off() callback.
To enable genpd to early abort the power off sequence for always on PM
domains, it needs static information about these configurations. Therefore
let's add a new genpd configuration flag, GENPD_FLAG_ALWAYS_ON.
Users of the new GENPD_FLAG_ALWAYS_ON flag, are by genpd required to make
sure the PM domain is powered on before calling pm_genpd_init(). Moreover,
users don't need to implement the ->power_off() callback, as genpd doesn't
ever invoke it.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There exists several similar validations of the genpd->status, against
GPD_STATE_ACTIVE and GPD_STATE_POWER_OFF. Let's clean up this code by
converting to use a helper macro, genpd_status_on().
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is no point running the conditional 'if' statement if the genpd
isn't present.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Once a subdomain is powered off, genpd queues a power off work for each of
the subdomain's corresponding masters, thus postponing the masters to be
powered off to a later point.
When genpd used intermediate power off states, which was removed in
commit ba2bbfbf63 ("PM / Domains: Remove intermediate states from the
power off sequence"), this behaviour made sense, but now it simply doesn't.
Genpd can easily try to power off the masters in the same context as the
subdomain, of course by acquiring/releasing the lock. Then, let's convert
to this behaviour, as it avoids unnecessary works from being queued.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The parameter name is_async, for genpd_power_off() gives a poor description
of its purpose. To clarify, let's rename it to one_dev_on and update the
documentation of it in the function header.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Following changes in genpd_power_on() makes it invoke genpd_power_off().
To enable these changes and avoiding to declare genpd_power_off(), let's
move its implementation above genpd_power_on(). In this way, following
changes should become easier to review.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
As the PM core may invoke the *noirq() callbacks asynchronously, the
current lock-less approach in genpd doesn't work. The consequence is that
we may find concurrent operations racing to power on/off the PM domain.
As of now, no immediate errors has been reported, but it's probably only a
matter time. Therefor let's fix the problem now before this becomes a real
issue, by deploying the locking scheme to the relevant functions.
Reported-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The earlier comment stated that the dev_warn_once() was going to be printed
once per device. Let's fix that, as dev_warn_once() is printed only once,
no matter of the device.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently the mix of genpd_poweron(), genpd_power_on(),
genpd_sync_poweron() and the ->power_on() callback, makes
a bit difficult to follow the path of execution. The similar
applies to the functions dealing with power off.
In a way to improve this understanding, let's do the following renaming:
genpd_power_on() -> _genpd_power_on()
genpd_poweron() -> genpd_power_on()
genpd_sync_poweron() -> genpd_sync_power_on()
genpd_power_off() -> _genpd_power_off()
genpd_poweroff() -> genpd_power_off()
genpd_sync_poweroff() -> genpd_sync_power_off()
genpd_poweroff_unused() -> genpd_power_off_unused()
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch fixes the following gcc warning:
drivers/base/power/domain.c: In function ‘genpd_runtime_resume’:
drivers/base/power/domain.c:642:14: warning: ‘time_start’ may be used
uninitialized in this function [-Wmaybe-uninitialized]
elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start)
The same problem (in another function in this same file) was fixed in
commit d33d5a6c88 (avoid spurious "may be used uninitialized" warning)
Signed-off-by: Augusto Mecking Caringi <augustocaringi@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The timer type simplifications caused a new gcc warning:
drivers/base/power/domain.c: In function ‘genpd_runtime_suspend’:
drivers/base/power/domain.c:562:14: warning: ‘time_start’ may be used uninitialized in this function [-Wmaybe-uninitialized]
elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
despite the actual use of "time_start" not having changed in any way.
It appears that simply changing the type of ktime_t from a union to a
plain scalar type made gcc check the use.
The variable wasn't actually used uninitialized, but gcc apparently
failed to notice that the conditional around the use was exactly the
same as the conditional around the initialization of that variable.
Add an unnecessary initialization just to shut up the compiler.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Re-using idle state definition provided by arm,idle-state for domain
idle states creates a lot of confusion and limits further evolution of
the domain idle definition. To keep things clear and simple, define a
idle states for domain using a new compatible "domain-idle-state".
Fix existing PM domains code to look for the newly defined compatible.
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
EPROBE_DEFER is not an error, hence printing an error message like
renesas_irqc e61c0000.interrupt-controller: failed to add to PM domain always-on: -517
may confuse the user.
Suppress the error message in case of EPROBE_DEFER to fix this.
Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The first argument of WARN() is the condition, followed by the message.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The return from of_count_phandle_with_args can be negative, so we
should avoid kcalloc of a negative count of genpd_power_stat structs
by sanity checking if count is zero or less.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Generic Power Domains currently support turning on/off only in process
context. This prevents the usage of PM domains for domains that could be
powered on/off in a context where IRQs are disabled. Many such domains
exist today and do not get powered off, when the IRQ safe devices in
that domain are powered off, because of this limitation.
However, not all domains can operate in IRQ safe contexts. Genpd
therefore, has to support both cases where the domain may or may not
operate in IRQ safe contexts. Configuring genpd to use an appropriate
lock for that domain, would allow domains that have IRQ safe devices to
runtime suspend and resume, in atomic context.
To achieve domain specific locking, set the domain's ->flag to
GENPD_FLAG_IRQ_SAFE while defining the domain. This indicates that genpd
should use a spinlock instead of a mutex for locking the domain. Locking
is abstracted through genpd_lock() and genpd_unlock() functions that use
the flag to determine the appropriate lock to be used for that domain.
Domains that have lower latency to suspend and resume and can operate
with IRQs disabled may now be able to save power, when the component
devices and sub-domains are idle at runtime.
The restriction this imposes on the domain hierarchy is that non-IRQ
safe domains may not have IRQ-safe subdomains, but IRQ safe domains may
have IRQ safe and non-IRQ safe subdomains and devices.
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Abstract genpd lock/unlock calls, in preparation for domain specific
locks added in the following patches.
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Save the fwnode for the genpd state in the state node. PM Domain clients
may use the fwnode to read in the platform specific domain state
properties and associate them with the state.
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch allows domains to define idle states in the DT. SoC's can
define domain idle states in DT using the "domain-idle-states" property
of the domain provider. Add API to read the idle states from DT that can
be set in the genpd object.
This patch is based on the original patch by Marc Titinger.
Signed-off-by: Marc Titinger <mtitinger+renesas@baylibre.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Allow PM Domain states to be defined dynamically by the drivers. This
removes the limitation on the maximum number of states possible for a
domain.
Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
These are internal static functions to genpd. Let's conform to the naming
rules, by dropping the "pm_" prefix from these.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Measure latency does by itself contribute to an increased latency, thus we
should avoid it when it isn't needed.
Currently genpd measures latencies in the system PM phase for the
->power_on|off() callbacks, except in the syscore case when it's not
allowed to use ktime_get() as timekeeping may be suspended.
Since there should be plenty of occasions during runtime PM to perform
these measurements, let's rely on that and drop them from system PM. This
will also make it consistent for how measurements are done of the runtime
PM callbacks (as those may be invoked during system PM).
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In cases when the PM domain haven't assigned a system PM callback, the PM
core fall-backs to check for the callback at the driver level instead.
This makes it redundant to assign a pm_generic_* helper function to a
corresponding system PM callback at a PM domain level.
Therefore, let's remove these assignments in pm_genpd_init().
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There's no need to validate the PM domain by using genpd_lookup_dev() when
removing the device via genpd's genpd_dev_pm_detach() function. That's
because this function can't be called, unless there is a valid PM domain
for the device.
To simplify the behaviour, let's move code from pm_genpd_remove_device()
into a new internal function, genpd_remove_device(), which is called from
pm_genpd_remove_device() and genpd_dev_pm_detach().
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In platforms such as Rockchip's, the array of domains isn't always
filled without holes, as which domains are present depend on the
particular SoC revision.
By allowing holes to be in the array, such SoCs can still use a single
set of constants to index the array of power domains.
Fixes: 0159ec6707 (PM / Domains: Verify the PM domain is present when adding a provider)
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If a device supports PM domains that are subdomains of another PM
domain, then the PM domains should be removed in reverse order to
ensure that the subdomains are removed first. Furthermore, if there is
more than one provider, then there needs to be a way to remove the
domains in reverse order for a specific provider.
Add the function of_genpd_remove_last() to remove the last PM domain
added by a given PM domain provider and return the generic_pm_domain
structure for the PM domain that was removed.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The genpd framework allows users to add PM domains via the pm_genpd_init()
function, however, there is no corresponding function to remove a PM
domain. For most devices this may be fine as the PM domains are never
removed, however, for devices that wish to populate the PM domains from
within a driver, having the ability to remove a PM domain if the probing
of the device fails or the driver is unloaded is necessary.
Add the function pm_genpd_remove() to remove a PM domain by referencing
it's generic_pm_domain structure. Note that the bulk of the code that
removes the PM domain is placed in a separate local function
genpd_remove() (which is called by pm_genpd_remove()). The code is
structured in this way to prepare for adding another function to remove
a PM domain by provider that will also call genpd_remove(). Note that
users of genpd_remove() must call this function with the mutex,
gpd_list_lock, held.
PM domains can only be removed if the associated provider has been
removed, they are not a parent domain to another PM domain and have no
devices associated with them.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It is possible that a device has more than one provider of PM domains
and to support the removal of a PM domain by provider, it is necessary
to store a reference to the provider in the PM domain structure.
Therefore, store a reference to the firmware node handle in the PM
domain structure and populate it when providers (only device-tree based
providers are currently supported by PM domains) are registered.
Please note that when removing PM domains, it is necessary to verify
that the PM domain provider has been removed from the list of providers
before the PM domain can be removed. To do this add another member to
the PM domain structure that indicates if the provider is present and
set this member accordingly when providers are added and removed.
Initialise the 'provider' and 'has_provider' members of the
generic_pm_domain structure when a PM domains is added by calling
pm_genpd_init().
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In order to remove PM domains safely from the list of PM domains,
it is necessary to adding locking for the PM domain list around any
places where devices or subdomains are added to a PM domain.
There are places where a reference to a PM domain is obtained via
calling of_genpd_get_from_provider() before adding the device or the
subdomain. In these cases a lock for the PM domain list needs to be
held around the call to of_genpd_get_from_provider() and the call to
add the device/subdomain. To avoid deadlocks by multiple attempts to
obtain the PM domain list lock, add functions genpd_add_device() and
genpd_add_subdomain() which require the user to hold the PM domain
list lock when calling.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When a PM domain provider is added, there is currently no way to tell if
any PM domains associated with the provider are present. Naturally, the
PM domain provider should not be registered if the PM domains have not
been added. Nonetheless, verify that the PM domain(s) associated with a
provider are present when registering the PM domain provider.
This change adds a dependency on the function pm_genpd_present() when
CONFIG_PM_GENERIC_DOMAINS_OF is enabled and so ensure this function is
available when CONFIG_PM_GENERIC_DOMAINS_OF selected.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Functions __of_genpd_xlate_simple(), __of_genpd_xlate_onecell() and
__of_genpd_add_provider() are not used outside of the core generic PM
domain code. Therefore, reduce the number of APIs exposed by making
these static. At the same time don't expose the typedef for
genpd_xlate_t either and make this a local definition as well.
The functions are renamed to follow the naming conventions for static
functions in the generic PM domain core.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There should be no need to expose the generic_pm_domain structure to
clients and this eliminates the need to implement reference counting for
any external reference to a PM domain. Therefore, make the functions
pm_genpd_lookup_dev() and of_genpd_get_from_provider() private to the
PM domain core. The functions are renamed in accordance with the naming
conventions for genpd static functions.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Ideally, if we are returning a reference to a PM domain via a call to
of_genpd_get_from_provider(), then we should keep track of such
references via a reference count. The reference count could then be used
to determine if a PM domain can be safely removed. Alternatively, it is
possible to avoid such external references by providing APIs to access
the PM domain and hence, eliminate any calls to
of_genpd_get_from_provider().
Add new helper functions for adding a device and a subdomain to a PM
domain when using device-tree, so that external calls to
of_genpd_get_from_provider() can be removed.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Debugfs support for PM domains is only enabled if both CONFIG_PM_DEBUG
and CONFIG_PM_ADVANCED_DEBUG are enabled. CONFIG_PM_ADVANCED_DEBUG is
described as "extra PM attributes in sysfs for low-level
debugging/testing" which does not seem related.
Given that the debugfs for PM domains only allows users to view the
state of the PM domains, always enable debugfs support for PM domains
if PM domains and debugfs support is enabled.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The are already cases when pm_genpd_init() can fail. Currently we hide the
failures instead of propagating an error code, which is a better method.
Moreover, to prepare for future changes like moving away from using a
fixed array-size of the struct genpd_power_state, to instead dynamically
allocate data for it, the pm_genpd_init() API needs to be able to return
an error code, as allocation can fail.
Current users of the pm_genpd_init() is thus requested to start dealing
with error codes. In the transition phase, users will have to live with
only error messages being printed to log.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Not all subsystems/drivers that manages devices attached to a genpd
makes use of the pm_runtime_force_suspend|resume() helper functions
to deal with system PM suspend/resume.
In cases like these and when genpd's ->stop|start() callbacks are
used for the device, invoke the pm_runtime_force_suspend|resume()
helper functions from genpd's "noirq" system PM callbacks. In this
way we make sure to "stop" the device on suspend and to "start" it
on resume.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In cases when a PM domain isn't powered off when genpd's ->prepare()
callback is invoked, genpd runtime resumes and disables runtime PM for the
device. This behaviour was needed when genpd managed intermediate states
during the power off sequence, as to maintain proper low power states of
devices during system PM suspend/resume.
Commit ba2bbfbf63 (PM / Domains: Remove intermediate states from the
power off sequence), enables genpd to improve its behaviour in that
respect.
The PM core disables runtime PM at __device_suspend_late() before it calls
a system PM "late" callback for a device. When resuming a device, after a
corresponding "early" callback has been invoked, the PM core re-enables
runtime PM.
By changing genpd to allow runtime PM according to the same system PM
phases as the PM core, devices can be runtime resumed by their
corresponding subsystem/driver when really needed.
In this way, genpd no longer need to runtime resume the device from its
->prepare() callback. In most cases that avoids unnecessary and energy-
wasting operations of runtime resuming devices that have nothing to do,
only to runtime suspend them shortly after.
Although, because of changing this behaviour in genpd and due to that
genpd powers on the PM domain unconditionally in the system PM resume
"noirq" phase, it could potentially cause a PM domain to stay powered
on even if it's unused after the system has resumed. To avoid this,
schedule a power off work when genpd's system PM ->complete() callback
has been invoked for the last device in the PM domain.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The PM core increases the runtime PM usage count at the system PM prepare
phase. Later when the system resumes, it does a pm_runtime_put() in the
complete phase, which in addition to decrementing the usage count, does
the equivalent of a pm_request_idle().
Therefore the call to pm_request_idle() from within genpd's ->complete()
callback is redundant, so remove it.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Due to the previous changes in genpd, which removed the suspend_power_off
flag, several of the system PM callbacks no longer do any additional
checks but only invoke corresponding pm_generic_* helper functions.
To clean up the code, drop these wrapper functions as they have
become redundant. Instead, assign the system PM callbacks directly
to the pm_generic_*() helper functions.
While changing this, it has bocame clear that some of the current
system PM callbacks in genpd invoke wrong driver callbacks. For
example, the genpd's ->restore() callback invokes pm_generic_resume(),
while that should be pm_generic_restore(). Fix that as well.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If a PM domain is powered off when the first device starts its system PM
prepare phase, genpd prevents any further attempts to power on the PM
domain during the following system PM phases. Not until the system PM
complete phase is finalized for all devices in the PM domain, genpd again
allows it to be powered on.
This behaviour needs to be changed, as a subsystem/driver for a device in
the same PM domain may still need to be able to serve requests in some of
the system PM phases. Accordingly, it may need to runtime resume its
device and thus also request the corresponding PM domain to be powered on.
To deal with these scenarios, let's make the device operational in the
system PM prepare phase by runtime resuming it, no matter if the PM domain
is powered on or off. Changing this also enables us to remove genpd's
suspend_power_off flag, as it's being used to track this condition.
Additionally, we must allow the PM domain to be powered on via runtime PM
during the system PM phases.
This change also requires a fix in the AMD ACP (Audio CoProcessor) drm
driver. It registers a genpd to model the ACP as a PM domain, but
unfortunately it's also abuses genpd's "internal" suspend_power_off flag
to deal with a corner case at system PM resume.
More precisely, the so called SMU block powers on the ACP at system PM
resume, unconditionally if it's being used or not. This may lead to that
genpd's internal status of the power state, may not correctly reflect the
power state of the HW after a system PM resume.
Because of changing the behaviour of genpd, by runtime resuming devices in
the prepare phase, the AMD ACP drm driver no longer have to deal with this
corner case. So let's just drop the related code in this driver.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Acked-by: Maruthi Bayyavarapu <maruthi.bayyavarapu@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
As the PM core already have wakeup management during the system PM phase,
it seems reasonable that genpd and its users should be able to rely on
that. Therefore let's remove this from pm_genpd_prepare().
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The PM core increases and decreases the runtime PM usage count in the
system PM prepare phase. This makes some of the pm_runtime_get|put*()
calls in pm_genpd_prepare() redundant, so let's remove them.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
As a part of the ongoing consolidation of genpd, it's become questionable
whether clients actually needs to be able to assign their own set of
->save|restore_state() callbacks. Currently all users copes fine with the
default callbacks, so let's remove the configuration option and stick to
the default ones.
This enables further clarifications of the related code and let's also
rename pm_genpd_default_save|restore_state() into
__genpd_runtime_suspend|resume() to apply the rule of static functionnames
in genpd.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Follow genpd's rule for names of static functions, by renaming
pm_genpd_runtime_suspend|resume() to genpd_runtime_suspend|resume().
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The genpd governor validates the latency constraints to find out whether
it's acceptable to runtime suspend a device. Earlier this validation was
made to know whether it was okay to invoke the ->stop() callback for the
device, hence the governor used the name "stop_ok" for the related
variables.
To clarify the code around this, let's rename these variables from
"stop_ok" to "suspend_ok".
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In the function of_genpd_get_from_provider(), we never check to see if
the argument 'genpdspec' is NULL before dereferencing it. Add error
checking to handle any NULL pointers.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit 30e7a65b3f (PM / Domains: Ensure subdomain is not in use
before removing) added a test to ensure that a subdomain is not a
master to another subdomain or if any devices are using the subdomain
before removing. This change incorrectly used the "slave_links" list to
determine if the subdomain is a master to another subdomain, where it
should have been using the "master_links" list instead. The
"slave_links" list will never be empty for a subdomain and so a
subdomain can never be removed. Fix this by testing if the
"master_links" list is empty instead.
Fixes: 30e7a65b3f (PM / Domains: Ensure subdomain is not in use before removing)
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
During runtime resume the return values of the start and restore steps
are ignored. As a result drivers are not notified of runtime resume
failures and can't propagate them up. Fix it by returning an error if
either the start or restore step fails, and clean up properly in the
error path.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
For low-power states, the state index is part of the state, hence join
them with a hyphen in the /sys/kernel/debug/pm_genpd/pm_genpd_summary
output. E.g. "off 0" becomes "off-0".
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The slave domains are no longer aligned with the table header in the
/sys/kernel/debug/pm_genpd/pm_genpd_summary output. Worse, the alignment
differs depending on the actual name of the state.
Format the state name and index into a buffer, and print that like
before to restore alignment.
Use "%u" for unsigned int while we're at it.
Fixes: fc5cbf0c94 (PM / Domains: Support for multiple states)
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Now that all known users have been converted to use state latencies,
we can remove the latency field in the generic_pm_domain structure.
Signed-off-by: Axel Haslam <ahaslam+renesas@baylibre.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Some hardware (eg. OMAP), has the ability to enter different low power
modes for a given power domain. This allows for more fine grained control
over the power state of the platform. As a typical example, some registers
of the hardware may be implemented with retention flip-flops and be able
to retain their state at lower voltages allowing for faster on/off
latencies and an increased window of opportunity to enter an intermediate
low power state other than "off"
When trying to set a power domain to off, the genpd governor will choose
the deepest state that will respect the qos constraints of all the devices
and sub-domains on the power domain. The state chosen by the governor is
saved in the "state_idx" field of the generic_pm_domain structure and
shall be used by the power_off and power_on callbacks to perform the
necessary actions to set the power domain into (and out of) the state
indicated by state_idx.
States must be declared in ascending order from shallowest to deepest,
deepest meaning the state which takes longer to enter and exit.
For platforms that don't declare any states, a single a single "off"
state is used. Once all platforms are converted to use the state array,
the legacy on/off latencies will be removed.
[ Lina: Modified genpd state initialization and remove use of
save_state_latency_ns in genpd timing data ]
Suggested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Axel Haslam <ahaslam+renesas@baylibre.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The only remaining caller of genpd_poweron() is conditionally compiled
based on CONFIG_PM_GENERIC_DOMAINS_OF, so we get a warning when that is
unset.
By moving the locking/unlocking of the genpd outside genpd_poweron(), thus
to the caller, genpd_poweron() becomes redundant.
Within this context let's then rename the wrapper function,
__genpd_poweron(), to genpd_poweron() as it will then be consistent with
its friend genpd_poweroff().
This change silence the warning about the unused function.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Fixes: ea823c7cbf "PM / Domains: Remove pm_genpd_poweron() API"
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-cpuidle:
cpuidle: coupled: remove unused define cpuidle_coupled_lock
cpuidle: fix fallback mechanism for suspend to idle in absence of enter_freeze
* pm-cpufreq:
cpufreq: cpufreq-dt: avoid uninitialized variable warnings:
cpufreq: pxa2xx: fix pxa_cpufreq_change_voltage prototype
cpufreq: Use list_is_last() to check last entry of the policy list
cpufreq: Fix NULL reference crash while accessing policy->governor_data
* pm-domains:
PM / Domains: Fix typo in comment
PM / Domains: Fix potential deadlock while adding/removing subdomains
PM / domains: fix lockdep issue for all subdomains
* pm-sleep:
PM: APM_EMULATION does not depend on PM
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We must preserve the same order of how we acquire and release the lock for
genpd, as otherwise we may encounter deadlocks.
The power on phase of a genpd starts by acquiring its lock. Then it walks
the hierarchy of its parent domains to be able to power on these first, as
per design of genpd.
From a locking perspective this means the locks of the parents becomes
acquired after the lock of the subdomain.
Let's fix pm_genpd_add|remove_subdomain() to maintain the same order of
acquiring/releasing the genpd lock as being applied in the power on/off
sequence.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
During genpd_poweron, genpd->lock is acquired recursively for each
parent (master) domain, which are separate objects. This confuses
lockdep, which considers every operation on genpd->lock as being done on
the same lock class. This leads to the following false positive warning:
=============================================
[ INFO: possible recursive locking detected ]
4.4.0-rc4-xu3s #32 Not tainted
---------------------------------------------
swapper/0/1 is trying to acquire lock:
(&genpd->lock){+.+...}, at: [<c0361550>] __genpd_poweron+0x64/0x108
but task is already holding lock:
(&genpd->lock){+.+...}, at: [<c0361af8>] genpd_dev_pm_attach+0x168/0x1b8
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&genpd->lock);
lock(&genpd->lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by swapper/0/1:
#0: (&dev->mutex){......}, at: [<c0350910>] __driver_attach+0x48/0x98
#1: (&dev->mutex){......}, at: [<c0350920>] __driver_attach+0x58/0x98
#2: (&genpd->lock){+.+...}, at: [<c0361af8>] genpd_dev_pm_attach+0x168/0x1b8
stack backtrace:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.0-rc4-xu3s #32
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c0016c98>] (unwind_backtrace) from [<c00139c4>] (show_stack+0x10/0x14)
[<c00139c4>] (show_stack) from [<c0270df0>] (dump_stack+0x84/0xc4)
[<c0270df0>] (dump_stack) from [<c00780b8>] (__lock_acquire+0x1f88/0x215c)
[<c00780b8>] (__lock_acquire) from [<c007886c>] (lock_acquire+0xa4/0xd0)
[<c007886c>] (lock_acquire) from [<c0641f2c>] (mutex_lock_nested+0x70/0x4d4)
[<c0641f2c>] (mutex_lock_nested) from [<c0361550>] (__genpd_poweron+0x64/0x108)
[<c0361550>] (__genpd_poweron) from [<c0361b00>] (genpd_dev_pm_attach+0x170/0x1b8)
[<c0361b00>] (genpd_dev_pm_attach) from [<c03520a8>] (platform_drv_probe+0x2c/0xac)
[<c03520a8>] (platform_drv_probe) from [<c03507d4>] (driver_probe_device+0x208/0x2fc)
[<c03507d4>] (driver_probe_device) from [<c035095c>] (__driver_attach+0x94/0x98)
[<c035095c>] (__driver_attach) from [<c034ec14>] (bus_for_each_dev+0x68/0x9c)
[<c034ec14>] (bus_for_each_dev) from [<c034fec8>] (bus_add_driver+0x1a0/0x218)
[<c034fec8>] (bus_add_driver) from [<c035115c>] (driver_register+0x78/0xf8)
[<c035115c>] (driver_register) from [<c0338488>] (exynos_drm_register_drivers+0x28/0x74)
[<c0338488>] (exynos_drm_register_drivers) from [<c0338594>] (exynos_drm_init+0x6c/0xc4)
[<c0338594>] (exynos_drm_init) from [<c00097f4>] (do_one_initcall+0x90/0x1dc)
[<c00097f4>] (do_one_initcall) from [<c0895e08>] (kernel_init_freeable+0x158/0x1f8)
[<c0895e08>] (kernel_init_freeable) from [<c063ecac>] (kernel_init+0x8/0xe8)
[<c063ecac>] (kernel_init) from [<c000f7d0>] (ret_from_fork+0x14/0x24)
This patch replaces mutex_lock with mutex_lock_nested() and uses
recursion depth to annotate each genpd->lock operation with separate
lockdep subclass.
Reported-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Tested-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-core:
driver core: Avoid NULL pointer dereferences in device_is_bound()
platform: Do not detach from PM domains on shutdown
USB / PM: Allow USB devices to remain runtime-suspended when sleeping
PM / sleep: Go direct_complete if driver has no callbacks
PM / Domains: add setter for dev.pm_domain
device core: add device_is_bound()
If a suitable prepare callback cannot be found for a given device and
its driver has no PM callbacks at all, assume that it can go direct to
complete when the system goes to sleep.
The reason for this is that there's lots of devices in a system that do
no PM at all and there's no reason for them to prevent their ancestors
to do direct_complete if they can support it.
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Adds a function that sets the pointer to dev_pm_domain in struct device
and that warns if the device has already finished probing. The reason
why we want to enforce that is because in the general case that can
cause problems and also that we can simplify code quite a bit if we can
always assume that.
This patch also changes all current code that directly sets the
dev.pm_domain pointer.
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Drivers which can be built as loadable module needs symbols
- pm_genpd_add_device/pm_genpd_remove_device to add/remove devices
to/from genpd. Those drivers create platform devices, which comes
under a powerdomain.
Signed-off-by: Maruthi Bayyavarapu <maruthi.bayyavarapu@amd.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
A runtime PM centric subsystem/driver may typically use the runtime PM
helpers, pm_runtime_force_suspend|resume() in the system PM path. This
means the genpd's runtime PM callbacks might be invoked even when runtime
PM has been disabled for the device.
To properly cope with these and similar scenarios when these helper
functions are used, change genpd to skip validating and measuring the
device PM QOS latency.
This is needed because otherwise genpd may prevent the device to be put
into low power state. If this occurs during system PM, it causes the
sequence to be aborted as a device's system PM callback returns -EBUSY.
Fixes: ba2bbfbf63 (PM / Domains: Remove intermediate states from the power off sequence)
Reported-by: Cao Minh Hiep <cm-hiep@jinso.co.jp>
Reported-by: Harunaga <nx-truong@jinso.co.jp>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: 4.3+ <stable@vger.kernel.org> # 4.3+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-domains:
PM / Domains: Fix bad of_node_put() in failure paths of genpd_dev_pm_attach()
PM / Domains: Validate cases of a non-bound driver in genpd governor
* pm-cpufreq:
cpufreq: use last policy after online for drivers with ->setpolicy
It looks like these meant to be unreffing the
of_parse_phandle_with_args() node, since the error paths above it
don't do of_node_put. That function returns a new ref in pd_args.np,
though, not a new ref on dev->of_node. Also, it would have leaked the
ref in the success case.
Fixes "ERROR: Bad of_node_put()" on bcm2835 in the -EPROBE_DEFER case.
Fixes: aa42240ab2 (PM / Domains: Add generic OF-based PM domain look-up)
Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Cc: 3.18+ <stable@vger.kernel.org> # 3.18+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Support for the ACPI _CCA configuration object intended to tell
the OS whether or not a bus master device supports hardware
managed cache coherency and a new set of functions to allow
drivers to check the cache coherency support for devices in a
platform firmware interface agnostic way (Suravee Suthikulpanit,
Jeremy Linton).
- ACPI backlight quirks for ESPRIMO Mobile M9410 and Dell XPS L421X
(Aaron Lu, Hans de Goede).
- Fixes for the arm_big_little and s5pv210-cpufreq cpufreq drivers
(Jon Medhurst, Nicolas Pitre).
- kfree()-related fixup for the recently introduced CPPC cpufreq
frontend (Markus Elfring).
- intel_pstate fix reducing kernel log noise on systems where
P-states are managed by hardware (Prarit Bhargava).
- intel_pstate maintainers information update (Srinivas Pandruvada).
- cpufreq core optimization related to the handling of delayed work
items used by governors (Viresh Kumar).
- Locking fixes and cleanups of the Operating Performance Points
(OPP) framework (Viresh Kumar).
- Generic power domains framework cleanups (Lina Iyer).
- cpupower tool updates (Jacob Tanenbaum, Sriram Raghunathan,
Thomas Renninger).
- turbostat tool updates (Len Brown).
/
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Merge tag 'pm+acpi-4.4-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more power management and ACPI updates from Rafael Wysocki:
"The only new feature in this batch is support for the ACPI _CCA device
configuration object, which it a pre-requisite for future ACPI PCI
support on ARM64, but should not affect the other architectures.
The rest is fixes and cleanups, mostly in cpufreq (including
intel_pstate), the Operating Performace Points (OPP) framework and
tools (cpupower and turbostat).
Specifics:
- Support for the ACPI _CCA configuration object intended to tell the
OS whether or not a bus master device supports hardware managed
cache coherency and a new set of functions to allow drivers to
check the cache coherency support for devices in a platform
firmware interface agnostic way (Suravee Suthikulpanit, Jeremy
Linton).
- ACPI backlight quirks for ESPRIMO Mobile M9410 and Dell XPS L421X
(Aaron Lu, Hans de Goede).
- Fixes for the arm_big_little and s5pv210-cpufreq cpufreq drivers
(Jon Medhurst, Nicolas Pitre).
- kfree()-related fixup for the recently introduced CPPC cpufreq
frontend (Markus Elfring).
- intel_pstate fix reducing kernel log noise on systems where
P-states are managed by hardware (Prarit Bhargava).
- intel_pstate maintainers information update (Srinivas Pandruvada).
- cpufreq core optimization related to the handling of delayed work
items used by governors (Viresh Kumar).
- Locking fixes and cleanups of the Operating Performance Points
(OPP) framework (Viresh Kumar).
- Generic power domains framework cleanups (Lina Iyer).
- cpupower tool updates (Jacob Tanenbaum, Sriram Raghunathan, Thomas
Renninger).
- turbostat tool updates (Len Brown)"
* tag 'pm+acpi-4.4-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
PCI: ACPI: Add support for PCI device DMA coherency
PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()
of/pci: Fix pci_get_host_bridge_device leak
device property: ACPI: Remove unused DMA APIs
device property: ACPI: Make use of the new DMA Attribute APIs
device property: Adding DMA Attribute APIs for Generic Devices
ACPI: Adding DMA Attribute APIs for ACPI Device
device property: Introducing enum dev_dma_attr
ACPI: Honor ACPI _CCA attribute setting
cpufreq: CPPC: Delete an unnecessary check before the function call kfree()
PM / OPP: Add opp_rcu_lockdep_assert() to _find_device_opp()
PM / OPP: Hold dev_opp_list_lock for writers
PM / OPP: Protect updates to list_dev with mutex
PM / OPP: Propagate error properly from dev_pm_opp_set_sharing_cpus()
cpufreq: s5pv210-cpufreq: fix wrong do_div() usage
MAINTAINERS: update for intel P-state driver
Creating a common structure initialization pattern for struct option
cpupower: Enable disabled Cstates if they are below max latency
cpupower: Remove debug message when using cpupower idle-set -D switch
cpupower: cpupower monitor reports uninitialized values for offline cpus
...
support. The core framework is mostly unchanged this time
around, with only a couple patches to expose a clk provider
API and make getting clk parent names from DT more robust.
Driver updates:
- Support for clock controllers found on Broadcom Northstar
SoCs and bcm2835 SoC
- Support for Allwinner audio clocks
- A few cleanup patches for Tegra drivers and support for the
highest DFLL frequencies on Tegra124
- Samsung exynos7 fixes and improvements
- i.Mx SoC updates to add a few missing clocks and keep debug
uart clocks on during kernel intialization
- Some mediatek cleanups and support for more subsystem clocks
- Support for msm8916 gpu/audio clocks and qcom's GDSC power domain
controllers
- A new driver for the Silabs si514 clock chip
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Merge tag 'clk-for-linus-20151104' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk updates from Stephen Boyd:
"The majority of the changes are driver updates and new device support.
The core framework is mostly unchanged this time around, with only a
couple patches to expose a clk provider API and make getting clk
parent names from DT more robust.
Driver updates:
- Support for clock controllers found on Broadcom Northstar SoCs and
bcm2835 SoC
- Support for Allwinner audio clocks
- A few cleanup patches for Tegra drivers and support for the highest
DFLL frequencies on Tegra124
- Samsung exynos7 fixes and improvements
- i.Mx SoC updates to add a few missing clocks and keep debug uart
clocks on during kernel intialization
- Some mediatek cleanups and support for more subsystem clocks
- Support for msm8916 gpu/audio clocks and qcom's GDSC power domain
controllers
- A new driver for the Silabs si514 clock chip"
* tag 'clk-for-linus-20151104' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (143 commits)
clk: qcom: msm8960: Fix dsi1/2 halt bits
clk: lpc18xx-cgu: fix potential system hang when disabling unused clocks
clk: lpc18xx-ccu: fix potential system hang when disabling unused clocks
clk: Add clk_hw_is_enabled() for use by clk providers
clk: Add stubs for of_clk_*() APIs when CONFIG_OF=n
clk: versatile-icst: fix memory leak
clk: Remove clk_{register,unregister}_multiplier()
clk: iproc: define Broadcom NS2 iProc clock binding
clk: iproc: define Broadcom NSP iProc clock binding
clk: ns2: add clock support for Broadcom Northstar 2 SoC
clk: iproc: Separate status and control variables
clk: iproc: Split off dig_filter
clk: iproc: Add PLL base write function
clk: nsp: add clock support for Broadcom Northstar Plus SoC
clk: iproc: Add PWRCTRL support
clk: cygnus: Convert all macros to all caps
ARM: cygnus: fix link failures when CONFIG_COMMON_CLK_IPROC is disabled
clk: imx31: add missing of_node_put
clk: imx27: add missing of_node_put
clk: si5351: add missing of_node_put
...
In preparation for supporting IRQ-safe domains, allocate domain data
outside the domain locks. These functions are not called in an atomic
context, so we can always allocate memory using GFP_KERNEL. By
allocating memory before the locks, we can safely lock the domain using
spinlocks instead of mutexes.
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Remove check for driver of a device, for runtime PM. Device may be
suspended without an explicit driver. This check seems to be vestigial
and incorrect in the current context.
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Measure latency does by itself contribute to an increased latency, thus we
should avoid it when it isn't needed.
By merging the latency measurements for the ->save_state() and the
->stop() callbacks, we get one measurement instead of two and we get one
value to store instead of two. Let's also apply the likewise change for
the ->start() and ->restore_state() callbacks.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Measure latency does by itself contribute to an increased latency, thus we
should avoid it when it isn't needed.
Genpd measures latencies in the system PM phase for the ->start|stop()
callbacks and is thus affecting the system PM suspend/resume time.
Moreover these latencies are validated only at runtime PM suspend/resume.
To this reasoning, let's decide to leave these measurements out of the
system PM phase. There should be plenty of occasions during runtime PM to
perform these measurements anyway.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This is another step to get consistent names of functions in genpd. Let's
rename the internal *pm_genpd_poweron|poweroff() into
*genpd_poweron|poweroff().
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Once genpd could be configured to be built with CONFIG_PM_RUNTIME unset
(nowadays CONFIG_PM), the pm_genpd_poweron() API served a purpose, since
it allowed users to power on a PM domain.
As such configuration no longer is supported, users shall solely rely on
using some of the runtime PM APIs to power on a PM domain.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
As the last user of the pm_genpd_poweroff_unused() API has moved into
relying on genpd to deal with this internally from a late_initcall, let's
remove the API.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit ba2bbfbf63 ("PM / Domains: Remove intermediate states..") changed
the power off sequence (pm_genpd_poweroff()), which from locking point of
view means the genpd mutex is held throughout the sequence.
The above change means the in_progress counter can't be updated while
pm_genpd_poweroff() is executing, which allows us to remove the counter.
Instead we inform pm_genpd_poweroff() via a bool parameter, to indicate
whether we call it from the scheduled work or from the ->runtime_suspend()
callback, since that all that matters.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Export these symbols so they can be used in loadable kernel
modules.
Cc: Rob Clark <robdclark@gmail.com>
Cc: Rajendra Nayak <rnayak@codeaurora.org>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
The power domains code allows to tie a cpuidle state with a power domain.
Preventing the cpuidle framework to enter a specific idle state by disabling
from the power domain framework is a good idea. Unfortunately, the current
implementation has some gaps with a SMP system and a complex cpuidle
implementation. Enabling a power domain wakes up all the cpus even if a cpu
does not belong to the power domain.
There is some work to do a logical representation with the power domains of
the hardware dependencies (eg. a cpu belongs to a power domains, these power
domains belong to a higher power domain for a cluster, etc ...). A new code
relying on the genpd hierarchy to disable the idle states would make more
sense.
As the unique user of this code has been removed, let's wipe out this code
to prevent new user and to have a clean place to put a new implementation.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
As all users of the named based APIs now have converted to the non-named
based APIs, the time has come to remove them.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The function pm_genpd_remove_subdomain() removes a subdomain from a
generic PM domain, however, it does not check if the subdomain has any
slave domains or device attached before doing so. Therefore, add a test
to verify that the subdomain does not have any slave domains associated
or any device attached before removing.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
While powering up a genpd, its domain masters are first being powered up.
In the error path of __pm_genpd_poweron(), we didn't care to try power off
these domain masters. Let's deal with that to avoid leaving unused PM
domains powered.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The function genpd_dev_pm_detach() detaches a device from a PM domain,
however, in the description, the "dev" argument for the function is
described as the device to "attach" instead of "detach". Correct this.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Export symbol pm_genpd_init so it can be used in loadable
kernel modules
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
"domain": header is indented by 4, data by 0 spaces => 0 spaces
"/device": header is indented by 11, data by 4 spaces => 4 spaces
"slaves": header is indented by 47, data by 49 spaces => 48 spaces
Ruler:
1234567890123456789012345678901234567890123456789012345678901234567890
Before:
domain status slaves
/device runtime status
----------------------------------------------------------------------
a3sp on a2us
/devices/platform/e60b0000.i2c suspended
After:
domain status slaves
/device runtime status
----------------------------------------------------------------------
a3sp on a2us
/devices/platform/e60b0000.i2c suspended
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When a device is probed, the function dev_pm_domain_attach() is called
to see if there is a power-domain that is associated with the device and
needs to be turned on. If dev_pm_domain_attach() does not return
-EPROBE_DEFER then the device will be probed.
For devices using genpd, dev_pm_domain_attach() will call
genpd_dev_pm_attach(). If genpd_dev_pm_attach() does not find a power
domain associated with the device then it returns an error code not
equal to -EPROBE_DEFER to allow the device to be probed. However, if
genpd_dev_pm_attach() does find a power-domain that is associated with
the device, then it does not return -EPROBE_DEFER on failure and hence
the device will still be probed. Furthermore, genpd_dev_pm_attach() does
not check the error code returned by pm_genpd_poweron() to see if the
power-domain was turned on successfully.
Fix this by checking the return code from pm_genpd_poweron() and
returning -EPROBE_DEFER from genpd_dev_pm_attach on failure, if there
is a power-domain associated with the device.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Genpd's ->runtime_suspend() (assigned to pm_genpd_runtime_suspend())
doesn't immediately walk the hierarchy of ->runtime_suspend() callbacks.
Instead, pm_genpd_runtime_suspend() calls pm_genpd_poweroff() which
postpones that until *all* the devices in the genpd are runtime suspended.
When pm_genpd_poweroff() discovers that the last device in the genpd is
about to be runtime suspended, it calls __pm_genpd_save_device() for *all*
the devices in the genpd sequentially. Furthermore,
__pm_genpd_save_device() invokes the ->start() callback, walks the
hierarchy of the ->runtime_suspend() callbacks and invokes the ->stop()
callback. This causes a "thundering herd" problem.
Let's address this issue by having pm_genpd_runtime_suspend() immediately
walk the hierarchy of the ->runtime_suspend() callbacks, instead of
postponing that to the power off sequence via pm_genpd_poweroff(). If the
selected ->runtime_suspend() callback doesn't return an error code, call
pm_genpd_poweroff() to see if it's feasible to also power off the PM
domain.
Adopting this change enables us to simplify parts of the code in genpd,
for example the locking mechanism. Additionally, it gives some positive
side effects, as described below.
i)
One device's ->runtime_resume() latency is no longer affected by other
devices' latencies in a genpd.
The complexity genpd has to support the option to abort the power off
sequence suffers from latency issues. More precisely, a device that is
requested to be runtime resumed, may end up waiting for
__pm_genpd_save_device() to complete its operations for *another* device.
That's because pm_genpd_poweroff() can't confirm an abort request while it
waits for __pm_genpd_save_device() to return.
As this patch removes the intermediate states in pm_genpd_poweroff() while
powering off the PM domain, we no longer need the ability to abort that
sequence.
ii)
Make pm_runtime[_status]_suspended() reliable when used with genpd.
Until the last device in a genpd becomes idle, pm_genpd_runtime_suspend()
will return 0 without actually walking the hierarchy of the
->runtime_suspend() callbacks. However, by returning 0 the runtime PM core
considers the device as runtime_suspended, so
pm_runtime[_status]_suspended() will return true, even though the device
isn't (yet) runtime suspended.
After this patch, since pm_genpd_runtime_suspend() immediately walks the
hierarchy of the ->runtime_suspend() callbacks,
pm_runtime[_status]_suspended() will accurately reflect the status of the
device.
iii)
Enable fine-grained PM through runtime PM callbacks in drivers/subsystems.
There are currently cases were drivers/subsystems implements runtime PM
callbacks to deploy fine-grained PM (e.g. gate clocks, move pinctrl to
power-save state, etc.). While using the genpd, pm_genpd_runtime_suspend()
postpones invoking these callbacks until *all* the devices in the genpd
are runtime suspended. In essence, one runtime resumed device prevents
fine-grained PM for other devices within the same genpd.
After this patch, since pm_genpd_runtime_suspend() immediately walks the
hierarchy of the ->runtime_suspend() callbacks, fine-grained PM is enabled
throughout all the levels of runtime PM callbacks.
iiii)
Enable fine-grained PM for IRQ safe devices
Per the definition for an IRQ safe device, its runtime PM callbacks must
be able to execute in atomic context. In the path while genpd walks the
hierarchy of the ->runtime_suspend() callbacks for the device, it uses a
mutex. Therefore, genpd prevents that path to be executed for IRQ safe
devices.
As this patch changes pm_genpd_runtime_suspend() to immediately walk the
hierarchy of the ->runtime_suspend() callbacks and without needing to use
a mutex, fine-grained PM is enabled throughout all the levels of runtime
PM callbacks for IRQ safe devices.
Unfortunately this patch also comes with a drawback, as described in the
summary below.
Driver's/subsystem's runtime PM callbacks may be invoked even when the
genpd hasn't actually powered off the PM domain, potentially introducing
unnecessary latency.
However, in most cases, saving/restoring register contexts for devices are
typically fast operations or can be optimized in device specific ways
(e.g. shadow copies of register contents in memory, device-specific checks
to see if context has been lost before restoring context, etc.).
Still, in some cases the driver/subsystem may suffer from latency if
runtime PM is used in a very fine-grained manner (e.g. for each IO request
or xfer). To prevent that extra overhead, the driver/subsystem may deploy
the runtime PM autosuspend feature.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If pm_genpd_{add,remove}_device() keeps on failing with -EAGAIN, we end
up with an infinite loop in genpd_dev_pm_{at,de}tach().
This may happen due to a genpd.prepared_count imbalance. This is a bug
elsewhere, but it will result in a system lock up, possibly during
reboot of an otherwise functioning system.
To avoid this, put a limit on the maximum number of loop iterations,
using an exponential back-off mechanism. If the limit is reached, the
operation will just fail. An error message is already printed.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The PM Domain code uses ktime_get() to perform various latency
measurements. However, if ktime_get() is called while timekeeping is
suspended, the following warning is printed:
WARNING: CPU: 0 PID: 1340 at kernel/time/timekeeping.c:576 ktime_get+0x3
This happens when resuming the PM Domain that contains the clock events
source, which calls pm_genpd_syscore_poweron(). Chain of operations is:
timekeeping_resume()
{
clockevents_resume()
sh_cmt_clock_event_resume()
pm_genpd_syscore_poweron()
pm_genpd_sync_poweron()
genpd_syscore_switch()
genpd_power_on()
ktime_get(), but timekeeping_suspended == 1
...
timekeeping_suspended = 0;
}
Fix this by adding a "timed" parameter to genpd_power_{on,off}() and
pm_genpd_sync_power{off,on}(), to indicate whether latency measurements
are allowed. This parameter is passed as false in
genpd_syscore_switch() (i.e. during syscore suspend/resume), and true in
all other cases.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
