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168 Commits (795bd2e7e86967ced927948eff08fe8201ba5fc3)

Author SHA1 Message Date
Ulf Hansson 795bd2e7e8 PM / Domains: Rename pm_genpd_runtime_suspend|resume()
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>
2016-04-22 02:29:17 +02:00
Ulf Hansson 9df3921e02 PM / Domains: Rename stop_ok to suspend_ok for the genpd governor
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>
2016-04-22 02:29:17 +02:00
Jon Hunter 41795a8a3c PM / Domains: Fix potential NULL pointer dereference
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>
2016-03-09 00:41:07 +01:00
Jon Hunter beda5fc1ff PM / Domains: Fix removal of a subdomain
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>
2016-03-09 00:41:06 +01:00
Laurent Pinchart 076395cae2 PM / Domains: Propagate start and restore errors during runtime resume
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>
2016-03-09 00:37:59 +01:00
Geert Uytterhoeven 0ba554e45c PM / Domains: Join state name and index in debugfs output
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>
2016-03-09 00:36:03 +01:00
Geert Uytterhoeven 6954d43292 PM / Domains: Restore alignment of slaves in debugfs output
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>
2016-03-09 00:36:03 +01:00
Axel Haslam 90e63452ac PM / Domains: remove old power on/off latencies
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>
2016-02-15 23:18:15 +01:00
Axel Haslam fc5cbf0c94 PM / Domains: Support for multiple states
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>
2016-02-15 23:18:15 +01:00
Ulf Hansson 53af16f79f PM / Domains: Silence compiler warning for an unused function
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>
2016-02-03 01:24:36 +01:00
Rafael J. Wysocki ad1ac94767 Merge branches 'pm-cpuidle', 'pm-cpufreq', 'pm-domains' and 'pm-sleep'
* 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
2016-01-29 21:45:17 +01:00
Moritz Fischer a3d09c7349 PM / Domains: Fix typo in comment
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>
2016-01-27 23:07:29 +01:00
Ulf Hansson cdb300a041 PM / Domains: Fix potential deadlock while adding/removing subdomains
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>
2016-01-27 23:01:25 +01:00
Marek Szyprowski 0106ef5146 PM / domains: fix lockdep issue for all subdomains
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>
2016-01-22 02:31:32 +01:00
Rafael J. Wysocki 6efd3f8cde Merge branch 'pm-core'
* 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()
2016-01-21 00:42:59 +01:00
Tomeu Vizoso aa8e54b559 PM / sleep: Go direct_complete if driver has no callbacks
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>
2016-01-08 01:12:06 +01:00
Tomeu Vizoso 989561de9b PM / Domains: add setter for dev.pm_domain
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>
2016-01-08 01:12:06 +01:00
Rafael J. Wysocki e219aafe50 Merge back earlier 'pm-domains' material for v4.5. 2015-12-21 03:14:03 +01:00
Rafael J. Wysocki f1b9fc591e Merge branches 'powercap', 'pm-cpufreq' and 'pm-domains'
* powercap:
  powercap / RAPL: fix BIOS lock check

* pm-cpufreq:
  cpufreq: intel_pstate: Minor cleanup for FRAC_BITS
  cpufreq: tegra: add regulator dependency for T124

* pm-domains:
  PM / Domains: Allow runtime PM callbacks to be re-used during system PM
2015-12-14 22:58:57 +01:00
Maruthi Bayyavarapu 24c96dc79c PM / Domains: export symbols to add/remove devices from genpd
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>
2015-12-10 01:39:12 +01:00
Ulf Hansson ffe12855a5 PM / Domains: Allow runtime PM callbacks to be re-used during system PM
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>
2015-12-10 01:37:34 +01:00
Rafael J. Wysocki d441fe25e7 Merge branches 'pm-domains' and 'pm-cpufreq'
* 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
2015-12-04 14:01:42 +01:00
Eric Anholt 265e2cf672 PM / Domains: Fix bad of_node_put() in failure paths of genpd_dev_pm_attach()
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>
2015-12-04 01:21:17 +01:00
Linus Torvalds be23c9d20b More power management and ACPI updates for v4.4-rc1
- 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
  ...
2015-11-12 11:50:33 -08:00
Linus Torvalds f66477a0ae 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
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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
  ...
2015-11-05 12:59:36 -08:00
Lina Iyer 2547923d1c PM / Domains: Allocate memory outside domain locks
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>
2015-11-02 02:26:17 +01:00
Lina Iyer 298cd0f088 PM / Domains: Remove dev->driver check for runtime PM
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>
2015-11-02 02:23:11 +01:00
Ulf Hansson 2b1d88cda3 PM / Domains: Merge measurements for PM QoS device latencies
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>
2015-10-28 04:33:04 +01:00
Ulf Hansson 51cda84489 PM / Domains: Don't measure ->start|stop() latency in system PM callbacks
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>
2015-10-28 04:33:04 +01:00
Ulf Hansson 7420aa4fed PM / Domains: Rename *pm_genpd_poweron|poweroff()
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>
2015-10-14 02:31:54 +02:00
Ulf Hansson ea823c7cbf PM / Domains: Remove pm_genpd_poweron() API
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>
2015-10-12 23:27:02 +02:00
Ulf Hansson bb4b72fc63 PM / Domains: Remove pm_genpd_poweroff_unused() API
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>
2015-10-12 23:27:02 +02:00
Ulf Hansson f96b3c4f34 PM / Domains: Remove in_progress counter from struct generic_pm_domain
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>
2015-10-12 23:19:55 +02:00
Stephen Boyd d60ee966b2 PM / Domains: Make pm_genpd_{add,remove}_subdomain() available to modules
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>
2015-10-08 23:52:55 -07:00
Rafael J. Wysocki 1462206cbc PM / domains: Drop unused label
Drop the "out" label in __pm_genpd_poweron() that's not used any more.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-27 15:20:30 +02:00
Daniel Lezcano cea3ad93d9 PM / Domains: Remove cpuidle attach
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>
2015-09-26 02:43:32 +02:00
Ulf Hansson c6f7b48e7e PM / Domains: Remove name based API for genpd
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>
2015-09-26 02:02:27 +02:00
Jon Hunter 30e7a65b3f PM / Domains: Ensure subdomain is not in use before removing
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>
2015-09-05 03:33:19 +02:00
Ulf Hansson 29e47e2173 PM / Domains: Try power off masters in error path of __pm_genpd_poweron()
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>
2015-09-03 02:53:53 +02:00
Jon Hunter 8bb6944e5a PM / Domains: Fix typo in description of genpd_dev_pm_detach()
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>
2015-08-29 01:55:39 +02:00
Rajendra Nayak be5ed55de0 PM / Domains: Make pm_genpd_init() available to modules
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>
2015-08-29 01:53:37 +02:00
Geert Uytterhoeven 15dec67ae3 PM / domains: Align column headers and data in pm_genpd_summary output
"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>
2015-08-29 01:50:07 +02:00
Jon Hunter 311fa6adf9 PM / Domains: Return -EPROBE_DEFER if we fail to init or turn-on domain
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>
2015-07-31 23:34:12 +02:00
Ulf Hansson ba2bbfbf63 PM / Domains: Remove intermediate states from the power off sequence
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>
2015-07-31 23:31:52 +02:00
Geert Uytterhoeven 93af5e9354 PM / Domains: Avoid infinite loops in attach/detach code
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>
2015-07-07 01:13:07 +02:00
Geert Uytterhoeven a4630c6127 PM / Domains: Skip timings during syscore suspend/resume
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>
2015-06-15 22:36:02 +02:00
Russell King df6a0d6f63 PM / domains: avoid potential oops in pm_genpd_remove_device()
pm_genpd_remove_device() tries hard to validate the generic PM domain
passed to it, but the validation is not complete.

dev->pm_domain contains a struct dev_pm_domain, which is the "base
class" of generic PM domains.  Other users of dev_pm_domains include
stuff like vga_switheroo.  Hence, a device could have a generic PM
domain or a vga_switcheroo PM domain in dev->pm_domain.

We need ot be certain that the PM domain is actually valid before we
try to remove it.  We can do this easily as we have a way to get the
current validated generic PM domain for a struct device.  This must
match the generic PM domain being requested for removal.

Convert the code to use this alternative validation method instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-23 23:20:28 +01:00
Russell King 446d999c1c PM / domains: factor out code to get the generic PM domain from a struct device
The PM domain code contains two methods to get the generic PM domain
for a struct device.  One is dev_to_genpd() which is only safe when
we know for certain that the device has a generic PM domain attached.
The other is coded into genpd_dev_pm_detach() which ensures that the
PM domain in the struct device is a generic PM domain (and so is safer).

This commit factors out the safer version, documents it, and hides the
unsafe dev_to_genpd().

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-22 22:19:12 +01:00
Russell King 6d7d5c3266 PM / domains: quieten down generic pm domains
PM domains are rather noisy; scheduling behaviour can cause callbacks
to take longer, which causes them to spit out a warning-level message
each time a callback takes a little longer than the previous time.
There really isn't a need for this, except when debugging.

Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-22 22:19:12 +01:00
Russell King 632f7ce3f9 PM / Domains: Sync runtime PM status with genpd after probe
Buses which currently supports attaching devices to their PM domains,
will invoke the dev_pm_domain_attach() API from their ->probe()
callbacks. During the attach procedure, genpd power up the PM domain.

In those scenarios where the bus/driver don't need to access its device
during probe, it may leave it in runtime PM suspended state since
that's also the default state. In that way, no notifications through
the runtime PM callbacks will reach the PM domain during probe.

For genpd, the consequence from the above scenario means the PM domain
will remain powered. Therefore, implement the struct dev_pm_domain's
->sync() callback, which is invoked from driver core after the
bus/driver has probed the device. It allows genpd to power off the PM
domain if it's unused.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
[ Ulf: Updated patch according to updates in driver core ]
Signed-off-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>
2015-03-22 22:15:11 +01:00