Commit Graph

170 Commits

Author SHA1 Message Date
Linus Torvalds 2504ba8b01 Power management updates for 6.3-rc1
- Add EPP support to the AMD P-state cpufreq driver (Perry Yuan, Wyes
    Karny, Arnd Bergmann, Bagas Sanjaya).
 
  - Drop the custom cpufreq driver for loongson1 that is not necessary
    any more and the corresponding cpufreq platform device (Keguang
    Zhang).
 
  - Remove "select SRCU" from system sleep, cpufreq and OPP Kconfig
    entries (Paul E. McKenney).
 
  - Enable thermal cooling for Tegra194 (Yi-Wei Wang).
 
  - Register module device table and add missing compatibles for
    cpufreq-qcom-hw (Nícolas F. R. A. Prado, Abel Vesa and Luca Weiss).
 
  - Various dt binding updates for qcom-cpufreq-nvmem and opp-v2-kryo-cpu
    (Christian Marangi).
 
  - Make kobj_type structure in the cpufreq core constant (Thomas
    Weißschuh).
 
  - Make cpufreq_unregister_driver() return void (Uwe Kleine-König).
 
  - Make the TEO cpuidle governor check CPU utilization in order to refine
   idle state selection (Kajetan Puchalski).
 
  - Make Kconfig select the haltpoll cpuidle governor when the haltpoll
    cpuidle driver is selected and replace a default_idle() call in that
    driver with arch_cpu_idle() to allow MWAIT to be used (Li RongQing).
 
  - Add Emerald Rapids Xeon support to the intel_idle driver (Artem
    Bityutskiy).
 
  - Add ARCH_SUSPEND_POSSIBLE dependencies for ARMv4 cpuidle drivers to
    avoid randconfig build failures (Arnd Bergmann).
 
  - Make kobj_type structures used in the cpuidle sysfs interface
    constant (Thomas Weißschuh).
 
  - Make the cpuidle driver registration code update microsecond values
    of idle state parameters in accordance with their nanosecond values
    if they are provided (Rafael Wysocki).
 
  - Make the PSCI cpuidle driver prevent topology CPUs from being
    suspended on PREEMPT_RT (Krzysztof Kozlowski).
 
  - Document that pm_runtime_force_suspend() cannot be used with
    DPM_FLAG_SMART_SUSPEND (Richard Fitzgerald).
 
  - Add EXPORT macros for exporting PM functions from drivers (Richard
    Fitzgerald).
 
  - Remove /** from non-kernel-doc comments in hibernation code (Randy
    Dunlap).
 
  - Fix possible name leak in powercap_register_zone() (Yang Yingliang).
 
  - Add Meteor Lake and Emerald Rapids support to the intel_rapl power
    capping driver (Zhang Rui).
 
  - Modify the idle_inject power capping facility to support 100% idle
    injection (Srinivas Pandruvada).
 
  - Fix large time windows handling in the intel_rapl power capping
    driver (Zhang Rui).
 
  - Fix memory leaks with using debugfs_lookup() in the generic PM
    domains and Energy Model code (Greg Kroah-Hartman).
 
  - Add missing 'cache-unified' property in the example for kryo OPP
    bindings (Rob Herring).
 
  - Fix error checking in opp_migrate_dentry() (Qi Zheng).
 
  - Let qcom,opp-fuse-level be a 2-long array for qcom SoCs (Konrad
    Dybcio).
 
  - Modify some power management utilities to use the canonical ftrace
    path (Ross Zwisler).
 
  - Correct spelling problems for Documentation/power/ as reported by
    codespell (Randy Dunlap).
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Merge tag 'pm-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "These add EPP support to the AMD P-state cpufreq driver, add support
  for new platforms to the Intel RAPL power capping driver, intel_idle
  and the Qualcomm cpufreq driver, enable thermal cooling for Tegra194,
  drop the custom cpufreq driver for loongson1 that is not necessary any
  more (and the corresponding cpufreq platform device), fix assorted
  issues and clean up code.

  Specifics:

   - Add EPP support to the AMD P-state cpufreq driver (Perry Yuan, Wyes
     Karny, Arnd Bergmann, Bagas Sanjaya)

   - Drop the custom cpufreq driver for loongson1 that is not necessary
     any more and the corresponding cpufreq platform device (Keguang
     Zhang)

   - Remove "select SRCU" from system sleep, cpufreq and OPP Kconfig
     entries (Paul E. McKenney)

   - Enable thermal cooling for Tegra194 (Yi-Wei Wang)

   - Register module device table and add missing compatibles for
     cpufreq-qcom-hw (Nícolas F. R. A. Prado, Abel Vesa and Luca Weiss)

   - Various dt binding updates for qcom-cpufreq-nvmem and
     opp-v2-kryo-cpu (Christian Marangi)

   - Make kobj_type structure in the cpufreq core constant (Thomas
     Weißschuh)

   - Make cpufreq_unregister_driver() return void (Uwe Kleine-König)

   - Make the TEO cpuidle governor check CPU utilization in order to
     refine idle state selection (Kajetan Puchalski)

   - Make Kconfig select the haltpoll cpuidle governor when the haltpoll
     cpuidle driver is selected and replace a default_idle() call in
     that driver with arch_cpu_idle() to allow MWAIT to be used (Li
     RongQing)

   - Add Emerald Rapids Xeon support to the intel_idle driver (Artem
     Bityutskiy)

   - Add ARCH_SUSPEND_POSSIBLE dependencies for ARMv4 cpuidle drivers to
     avoid randconfig build failures (Arnd Bergmann)

   - Make kobj_type structures used in the cpuidle sysfs interface
     constant (Thomas Weißschuh)

   - Make the cpuidle driver registration code update microsecond values
     of idle state parameters in accordance with their nanosecond values
     if they are provided (Rafael Wysocki)

   - Make the PSCI cpuidle driver prevent topology CPUs from being
     suspended on PREEMPT_RT (Krzysztof Kozlowski)

   - Document that pm_runtime_force_suspend() cannot be used with
     DPM_FLAG_SMART_SUSPEND (Richard Fitzgerald)

   - Add EXPORT macros for exporting PM functions from drivers (Richard
     Fitzgerald)

   - Remove /** from non-kernel-doc comments in hibernation code (Randy
     Dunlap)

   - Fix possible name leak in powercap_register_zone() (Yang Yingliang)

   - Add Meteor Lake and Emerald Rapids support to the intel_rapl power
     capping driver (Zhang Rui)

   - Modify the idle_inject power capping facility to support 100% idle
     injection (Srinivas Pandruvada)

   - Fix large time windows handling in the intel_rapl power capping
     driver (Zhang Rui)

   - Fix memory leaks with using debugfs_lookup() in the generic PM
     domains and Energy Model code (Greg Kroah-Hartman)

   - Add missing 'cache-unified' property in the example for kryo OPP
     bindings (Rob Herring)

   - Fix error checking in opp_migrate_dentry() (Qi Zheng)

   - Let qcom,opp-fuse-level be a 2-long array for qcom SoCs (Konrad
     Dybcio)

   - Modify some power management utilities to use the canonical ftrace
     path (Ross Zwisler)

   - Correct spelling problems for Documentation/power/ as reported by
     codespell (Randy Dunlap)"

* tag 'pm-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (53 commits)
  Documentation: amd-pstate: disambiguate user space sections
  cpufreq: amd-pstate: Fix invalid write to MSR_AMD_CPPC_REQ
  dt-bindings: opp: opp-v2-kryo-cpu: enlarge opp-supported-hw maximum
  dt-bindings: cpufreq: qcom-cpufreq-nvmem: make cpr bindings optional
  dt-bindings: cpufreq: qcom-cpufreq-nvmem: specify supported opp tables
  PM: Add EXPORT macros for exporting PM functions
  cpuidle: psci: Do not suspend topology CPUs on PREEMPT_RT
  MIPS: loongson32: Drop obsolete cpufreq platform device
  powercap: intel_rapl: Fix handling for large time window
  cpuidle: driver: Update microsecond values of state parameters as needed
  cpuidle: sysfs: make kobj_type structures constant
  cpuidle: add ARCH_SUSPEND_POSSIBLE dependencies
  PM: EM: fix memory leak with using debugfs_lookup()
  PM: domains: fix memory leak with using debugfs_lookup()
  cpufreq: Make kobj_type structure constant
  cpufreq: davinci: Fix clk use after free
  cpufreq: amd-pstate: avoid uninitialized variable use
  cpufreq: Make cpufreq_unregister_driver() return void
  OPP: fix error checking in opp_migrate_dentry()
  dt-bindings: cpufreq: cpufreq-qcom-hw: Add SM8550 compatible
  ...
2023-02-21 12:13:58 -08:00
Richard Fitzgerald 450316dc4f PM: runtime: Document that force_suspend() is incompatible with SMART_SUSPEND
pm_runtime_force_suspend() cannot be used with DPM_FLAG_SMART_SUSPEND, so
note this in the kerneldoc.

If DPM_FLAG_SMART_SUSPEND is set and the PM core cannot skip system resume
it will call pm_runtime_active() on the driver. This can lead to an
inconsistent state where:

  pm_runtime_force_suspend() called ->runtime_suspend

but

  device_resume_noirq() called pm_runtime_set_active()

This leaves the driver actually suspended but marked as active.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-01-13 20:53:44 +01:00
Peter Zijlstra db8f50861d cpuidle, ARM: OMAP2+: powerdomain: Remove trace_.*_rcuidle()
OMAP was the one and only user.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195541.782536366@infradead.org
2023-01-13 11:48:17 +01:00
Rafael J. Wysocki dbfa447827 PM: runtime: Adjust white space in the core code
Some inconsistent usage of white space in the PM-runtime core code
causes that code to be somewhat harder to read that it would have
been otherwise, so adjust the white space in there to be more
consistent with the rest of the code.

No expected functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-12-07 18:23:32 +01:00
Rafael J. Wysocki 0307f4e8ff PM: runtime: Relocate rpm_callback() right after __rpm_callback()
Because rpm_callback() is a wrapper around __rpm_callback(), and the
only caller of it after the change eliminating an invocation of it
from rpm_idle(), move the former next to the latter to make the code
a bit easier to follow.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
2022-12-05 15:43:37 +01:00
Rafael J. Wysocki bc80c2e438 PM: runtime: Do not call __rpm_callback() from rpm_idle()
Calling __rpm_callback() from rpm_idle() after adding device links
support to the former is a clear mistake.

Not only it causes rpm_idle() to carry out unnecessary actions, but it
is also against the assumption regarding the stability of PM-runtime
status across __rpm_callback() invocations, because rpm_suspend() and
rpm_resume() may run in parallel with __rpm_callback() when it is called
by rpm_idle() and the device's PM-runtime status can be updated by any
of them.

Fixes: 21d5c57b37 ("PM / runtime: Use device links")
Link: https://lore.kernel.org/linux-pm/36aed941-a73e-d937-2721-4f0decd61ce0@quicinc.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
2022-12-05 15:43:37 +01:00
Rafael J. Wysocki e66332a4bc PM: runtime: Return -EINPROGRESS from rpm_resume() in the RPM_NOWAIT case
The prospective callers of rpm_resume() passing RPM_NOWAIT to it may
be confused when it returns 0 without actually resuming the device
which may happen if the device is suspending at the given time and it
will only resume when the suspend in progress has completed.  To avoid
that confusion, return -EINPROGRESS from rpm_resume() in that case.

Since none of the current callers passing RPM_NOWAIT to rpm_resume()
check its return value, this change has no functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2022-09-24 19:28:51 +02:00
Ulf Hansson c46a0d5ae4 PM: runtime: Extend support for wakeirq for force_suspend|resume
A driver that makes use of pm_runtime_force_suspend|resume() to support
system suspend/resume, currently needs to manage the wakeirq support
itself. To avoid the boilerplate code in the driver's system suspend/resume
callbacks in particular, let's extend pm_runtime_force_suspend|resume() to
deal with the wakeirq.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-07-08 21:29:06 +02:00
Rafael J. Wysocki 8873710660 PM: runtime: Fix supplier device management during consumer probe
Because pm_runtime_get_suppliers() bumps up the rpm_active counter
of each device link to a supplier of the given device in addition
to bumping up the supplier's PM-runtime usage counter, a runtime
suspend of the consumer device may case the latter to go down to 0
when pm_runtime_put_suppliers() is running on a remote CPU.  If that
happens after pm_runtime_put_suppliers() has released power.lock for
the consumer device, and a runtime resume of that device takes place
immediately after it, before pm_runtime_put() is called for the
supplier, that pm_runtime_put() call may cause the supplier to be
suspended even though the consumer is active.

To prevent that from happening, modify pm_runtime_get_suppliers() to
call pm_runtime_get_sync() for the given device's suppliers without
touching the rpm_active counters of the involved device links
Accordingly, modify pm_runtime_put_suppliers() to call pm_runtime_put()
for the given device's suppliers without looking at the rpm_active
counters of the device links at hand.  [This is analogous to what
happened before commit 4c06c4e6cf ("driver core: Fix possible
supplier PM-usage counter imbalance").]

Since pm_runtime_get_suppliers() sets supplier_preactivated for each
device link where the supplier's PM-runtime usage counter has been
incremented and pm_runtime_put_suppliers() calls pm_runtime_put() for
the suppliers whose device links have supplier_preactivated set, the
PM-runtime usage counter is balanced for each supplier and this is
independent of the runtime suspend and resume of the consumer device.

However, in case a device link with DL_FLAG_PM_RUNTIME set is dropped
during the consumer device probe, so pm_runtime_get_suppliers() bumps
up the supplier's PM-runtime usage counter, but it cannot be dropped by
pm_runtime_put_suppliers(), make device_link_release_fn() take care of
that.

Fixes: 4c06c4e6cf ("driver core: Fix possible supplier PM-usage counter imbalance")
Reported-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Cc: 5.1+ <stable@vger.kernel.org> # 5.1+
2022-07-01 21:04:15 +02:00
Rafael J. Wysocki 07358194ba PM: runtime: Redefine pm_runtime_release_supplier()
Instead of passing an extra bool argument to pm_runtime_release_supplier(),
make its callers take care of triggering a runtime-suspend of the
supplier device as needed.

No expected functional impact.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: 5.1+ <stable@vger.kernel.org> # 5.1+
2022-07-01 21:04:02 +02:00
Rafael J. Wysocki 95f2ce548a Merge branches 'pm-core', 'pm-sleep' and 'powercap'
Merge PM core changes, updates related to system sleep and power capping
updates for 5.19-rc1:

 - Export dev_pm_ops instead of suspend() and resume() in the IIO
   chemical scd30 driver (Jonathan Cameron).

 - Add namespace variants of EXPORT[_GPL]_SIMPLE_DEV_PM_OPS and
   PM-runtime counterparts (Jonathan Cameron).

 - Move symbol exports in the IIO chemical scd30 driver into the
   IIO_SCD30 namespace (Jonathan Cameron).

 - Avoid device PM-runtime usage count underflows (Rafael Wysocki).

 - Allow dynamic debug to control printing of PM messages  (David
   Cohen).

 - Fix some kernel-doc comments in hibernation code (Yang Li, Haowen
   Bai).

 - Preserve ACPI-table override during hibernation (Amadeusz Sławiński).

 - Improve support for suspend-to-RAM for PSCI OSI mode (Ulf Hansson).

 - Make Intel RAPL power capping driver support the RaptorLake and
   AlderLake N processors (Zhang Rui, Sumeet Pawnikar).

 - Remove redundant store to value after multiply in the RAPL power
   capping driver (Colin Ian King).

* pm-core:
  PM: runtime: Avoid device usage count underflows
  iio: chemical: scd30: Move symbol exports into IIO_SCD30 namespace
  PM: core: Add NS varients of EXPORT[_GPL]_SIMPLE_DEV_PM_OPS and runtime pm equiv
  iio: chemical: scd30: Export dev_pm_ops instead of suspend() and resume()

* pm-sleep:
  cpuidle: PSCI: Improve support for suspend-to-RAM for PSCI OSI mode
  PM: runtime: Allow to call __pm_runtime_set_status() from atomic context
  PM: hibernate: Don't mark comment as kernel-doc
  x86/ACPI: Preserve ACPI-table override during hibernation
  PM: hibernate: Fix some kernel-doc comments
  PM: sleep: enable dynamic debug support within pm_pr_dbg()
  PM: sleep: Narrow down -DDEBUG on kernel/power/ files

* powercap:
  powercap: intel_rapl: remove redundant store to value after multiply
  powercap: intel_rapl: add support for ALDERLAKE_N
  powercap: RAPL: Add Power Limit4 support for RaptorLake
  powercap: intel_rapl: add support for RaptorLake
2022-05-23 19:06:33 +02:00
Ulf Hansson 13966517d4 PM: runtime: Allow to call __pm_runtime_set_status() from atomic context
The only two users of __pm_runtime_set_status() are pm_runtime_set_active()
and pm_runtime_set_suspended(). These are widely used and should be called
from non-atomic context to work as expected. However, it would be
convenient to allow them be called from atomic context too, as shown from a
subsequent change, so let's add support for this.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Maulik Shah <quic_mkshah@quicinc.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-19 17:24:02 +02:00
Rafael J. Wysocki 82586a7215 PM: runtime: Avoid device usage count underflows
A PM-runtime device usage count underflow is potentially critical,
because it may cause a device to be suspended when it is expected to
be operational.  It is also a programming problem that would be good
to catch and warn about.

For this reason, (1) make rpm_check_suspend_allowed() return an error
when the device usage count is negative to prevent devices from being
suspended in that case, (2) introduce rpm_drop_usage_count() that will
detect device usage count underflows, warn about them and fix them up,
and (3) use it to drop the usage count in a few places instead of
atomic_dec_and_test().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2022-04-13 17:30:32 +02:00
Douglas Anderson b4060db925 PM: runtime: Have devm_pm_runtime_enable() handle pm_runtime_dont_use_autosuspend()
The PM Runtime docs say:

  Drivers in ->remove() callback should undo the runtime PM changes done
  in ->probe(). Usually this means calling pm_runtime_disable(),
  pm_runtime_dont_use_autosuspend() etc.

From grepping code, it's clear that many people aren't aware of the
need to call pm_runtime_dont_use_autosuspend().

When brainstorming solutions, one idea that came up was to leverage
the new-ish devm_pm_runtime_enable() function. The idea here is that:

 * When the devm action is called we know that the driver is being
   removed. It's the perfect time to undo the use_autosuspend.

 * The code of pm_runtime_dont_use_autosuspend() already handles the
   case of being called when autosuspend wasn't enabled.

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-03-04 18:26:54 +01:00
Rafael J. Wysocki 50a4606655 PM: runtime: Simplify locking in pm_runtime_put_suppliers()
Notice that pm_runtime_put_suppliers() cannot be called with
disabled interrupts, because it may sleep (due to the device
links read locking in the non-SRCU case), and so it can use
spin_lock_irq() and spin_unlock_irq() for the locking.

Update the function accordingly and while at it move the "put"
local variable in it into the inner block where it is used.

This change is not expected to have any visible functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2021-12-22 18:37:55 +01:00
Rafael J. Wysocki d1579e6119 PM: runtime: Add safety net to supplier device release
Because refcount_dec_not_one() returns true if the target refcount
becomes saturated, it is generally unsafe to use its return value as
a loop termination condition, but that is what happens when a device
link's supplier device is released during runtime PM suspend
operations and on device link removal.

To address this, introduce pm_runtime_release_supplier() to be used
in the above cases which will check the supplier device's runtime
PM usage counter in addition to the refcount_dec_not_one() return
value, so the loop can be terminated in case the rpm_active refcount
value becomes invalid, and update the code in question to use it as
appropriate.

This change is not expected to have any visible functional impact.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-12-17 16:25:14 +01:00
Rafael J. Wysocki c24efa6732 PM: runtime: Capture device status before disabling runtime PM
In some cases (for example, during system-wide suspend and resume of
devices) it is useful to know whether or not runtime PM has ever been
enabled for a given device and, if so, what the runtime PM status of
it had been right before runtime PM was disabled for it last time.

For this reason, introduce a new struct dev_pm_info field called
last_status that will be used for capturing the runtime PM status of
the device when its power.disable_depth counter changes from 0 to 1.

The new field will be set to RPM_INVALID to start with and whenever
power.disable_depth changes from 1 to 0, so it will be valid only
when runtime PM of the device is currently disabled, but it has been
enabled at least once.

Immediately use power.last_status in rpm_resume() to make it handle
the case when PM runtime is disabled for the device, but its runtime
PM status is RPM_ACTIVE more consistently.  Namely, make it return 1
if power.last_status is also equal to RPM_ACTIVE in that case (the
idea being that if the status was RPM_ACTIVE last time when
power.disable_depth was changing from 0 to 1 and it is still
RPM_ACTIVE, it can be assumed to reflect what happened to the device
last time when it was using runtime PM) and -EACCES otherwise.

Update the documentation to provide a description of last_status and
change the description of pm_runtime_resume() in it to reflect the
new behavior of rpm_active().

While at it, rearrange the code in pm_runtime_enable() to be more
straightforward and replace the WARN() macro in it with a pr_warn()
invocation which is less disruptive.

Link: https://lore.kernel.org/linux-pm/20211026222626.39222-1-ulf.hansson@linaro.org/t/#u
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-12-17 16:16:40 +01:00
Chunfeng Yun 259714100d PM / wakeirq: support enabling wake-up irq after runtime_suspend called
When the dedicated wake IRQ is level trigger, and it uses the
device's low-power status as the wakeup source, that means if the
device is not in low-power state, the wake IRQ will be triggered
if enabled; For this case, need enable the wake IRQ after running
the device's ->runtime_suspend() which make it enter low-power state.

e.g.
Assume the wake IRQ is a low level trigger type, and the wakeup
signal comes from the low-power status of the device.
The wakeup signal is low level at running time (0), and becomes
high level when the device enters low-power state (runtime_suspend
(1) is called), a wakeup event at (2) make the device exit low-power
state, then the wakeup signal also becomes low level.

                ------------------
               |           ^     ^|
----------------           |     | --------------
 |<---(0)--->|<--(1)--|   (3)   (2)    (4)

if enable the wake IRQ before running runtime_suspend during (0),
a wake IRQ will arise, it causes resume immediately;
it works if enable wake IRQ ( e.g. at (3) or (4)) after running
->runtime_suspend().

This patch introduces a new status WAKE_IRQ_DEDICATED_REVERSE to
optionally support enabling wake IRQ after running ->runtime_suspend().

Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-10-27 20:49:32 +02:00
Dmitry Baryshkov b3636a3a2c PM: runtime: add devm_pm_runtime_enable helper
A typical code pattern for pm_runtime_enable() call is to call it in the
_probe function and to call pm_runtime_disable() both from _probe error
path and from _remove function. For some drivers the whole remove
function would consist of the call to pm_remove_disable().

Add helper function to replace this bolierplate piece of code. Calling
devm_pm_runtime_enable() removes the need for calling
pm_runtime_disable() both in the probe()'s error path and in the
remove() function.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20210731195034.979084-2-dmitry.baryshkov@linaro.org
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2021-08-26 11:27:51 -07:00
Ulf Hansson 63d00be693 PM: runtime: Allow unassigned ->runtime_suspend|resume callbacks
We are currently allowing ->runtime_idle() callbacks to be unassigned
without returning an error code from rpm_idle(). This has been useful to
avoid boilerplate code in drivers. Let's take this approach a step further,
by allowing also unassigned ->runtime_suspend|resume() callbacks.

In this way, a consumer/supplier device link can be used to let a consumer
device be power managed through its supplier device, without requiring
assigned ->runtime_suspend|resume() callbacks for the consumer device, for
example.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-06-11 19:03:01 +02:00
Ulf Hansson 5a2bd1b1c6 PM: runtime: Improve path in rpm_idle() when no callback
When pm_runtime_no_callbacks() has been called for a struct device to set
the dev->power.no_callbacks flag for it, it enables rpm_idle() to take a
slightly quicker path by assuming that a ->runtime_idle() callback would
have returned 0 to indicate success.

A device that does not have the dev->power.no_callbacks flag set for it,
may still be missing a corresponding ->runtime_idle() callback, in which
case the slower path in rpm_idle() is taken. Let's improve the behaviour
for this case, by aligning code to the quicker path.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-06-11 19:03:01 +02:00
Tony Lindgren c745253e2a PM: runtime: Fix unpaired parent child_count for force_resume
As pm_runtime_need_not_resume() relies also on usage_count, it can return
a different value in pm_runtime_force_suspend() compared to when called in
pm_runtime_force_resume(). Different return values can happen if anything
calls PM runtime functions in between, and causes the parent child_count
to increase on every resume.

So far I've seen the issue only for omapdrm that does complicated things
with PM runtime calls during system suspend for legacy reasons:

omap_atomic_commit_tail() for omapdrm.0
 dispc_runtime_get()
  wakes up 58000000.dss as it's the dispc parent
   dispc_runtime_resume()
    rpm_resume() increases parent child_count
 dispc_runtime_put() won't idle, PM runtime suspend blocked
pm_runtime_force_suspend() for 58000000.dss, !pm_runtime_need_not_resume()
 __update_runtime_status()
system suspended
pm_runtime_force_resume() for 58000000.dss, pm_runtime_need_not_resume()
 pm_runtime_enable() only called because of pm_runtime_need_not_resume()
omap_atomic_commit_tail() for omapdrm.0
 dispc_runtime_get()
  wakes up 58000000.dss as it's the dispc parent
   dispc_runtime_resume()
    rpm_resume() increases parent child_count
 dispc_runtime_put() won't idle, PM runtime suspend blocked
...
rpm_suspend for 58000000.dss but parent child_count is now unbalanced

Let's fix the issue by adding a flag for needs_force_resume and use it in
pm_runtime_force_resume() instead of pm_runtime_need_not_resume().

Additionally omapdrm system suspend could be simplified later on to avoid
lots of unnecessary PM runtime calls and the complexity it adds. The
driver can just use internal functions that are shared between the PM
runtime and system suspend related functions.

Fixes: 4918e1f87c ("PM / runtime: Rework pm_runtime_force_suspend/resume()")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Cc: 4.16+ <stable@vger.kernel.org> # 4.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-05-10 19:14:01 +02:00
Pierre-Louis Bossart 12c0632b25 PM: runtime: remove kernel-doc warnings
remove make W=1 warnings

drivers/base/power/runtime.c:926: warning: Function parameter or
member 'timer' not described in 'pm_suspend_timer_fn'

drivers/base/power/runtime.c:926: warning: Excess function parameter
'data' description in 'pm_suspend_timer_fn'

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-04-07 19:21:09 +02:00
Adrian Hunter 9dfacc54a8 PM: runtime: Fix race getting/putting suppliers at probe
pm_runtime_put_suppliers() must not decrement rpm_active unless the
consumer is suspended. That is because, otherwise, it could suspend
suppliers for an active consumer.

That can happen as follows:

 static int driver_probe_device(struct device_driver *drv, struct device *dev)
 {
	int ret = 0;

	if (!device_is_registered(dev))
		return -ENODEV;

	dev->can_match = true;
	pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
		 drv->bus->name, __func__, dev_name(dev), drv->name);

	pm_runtime_get_suppliers(dev);
	if (dev->parent)
		pm_runtime_get_sync(dev->parent);

 At this point, dev can runtime suspend so rpm_put_suppliers() can run,
 rpm_active becomes 1 (the lowest value).

	pm_runtime_barrier(dev);
	if (initcall_debug)
		ret = really_probe_debug(dev, drv);
	else
		ret = really_probe(dev, drv);

 Probe callback can have runtime resumed dev, and then runtime put
 so dev is awaiting autosuspend, but rpm_active is 2.

	pm_request_idle(dev);

	if (dev->parent)
		pm_runtime_put(dev->parent);

	pm_runtime_put_suppliers(dev);

 Now pm_runtime_put_suppliers() will put the supplier
 i.e. rpm_active 2 -> 1, but consumer can still be active.

	return ret;
 }

Fix by checking the runtime status. For any status other than
RPM_SUSPENDED, rpm_active can be considered to be "owned" by
rpm_[get/put]_suppliers() and pm_runtime_put_suppliers() need do nothing.

Reported-by: Asutosh Das <asutoshd@codeaurora.org>
Fixes: 4c06c4e6cf ("driver core: Fix possible supplier PM-usage counter imbalance")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: 5.1+ <stable@vger.kernel.org> # 5.1+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-03-29 19:27:09 +02:00
Adrian Hunter c0c33442f7 PM: runtime: Fix ordering in pm_runtime_get_suppliers()
rpm_active indicates how many times the supplier usage_count has been
incremented. Consequently it must be updated after pm_runtime_get_sync() of
the supplier, not before.

Fixes: 4c06c4e6cf ("driver core: Fix possible supplier PM-usage counter imbalance")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: 5.1+ <stable@vger.kernel.org> # 5.1+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-03-29 19:27:09 +02:00
Rafael J. Wysocki 5244f5e2d8 PM: runtime: Defer suspending suppliers
Because the PM-runtime status of the device is not updated in
__rpm_callback(), attempts to suspend the suppliers of the given
device triggered by the rpm_put_suppliers() call in there may
cause a supplier to be suspended completely before the status of
the consumer is updated to RPM_SUSPENDED, which is confusing.

To avoid that (1) modify __rpm_callback() to only decrease the
PM-runtime usage counter of each supplier and (2) make rpm_suspend()
try to suspend the suppliers after changing the consumer's status to
RPM_SUSPENDED, in analogy with the device's parent.

Link: https://lore.kernel.org/linux-pm/CAPDyKFqm06KDw_p8WXsM4dijDbho4bb6T4k50UqqvR1_COsp8g@mail.gmail.com/
Fixes: 21d5c57b37 ("PM / runtime: Use device links")
Reported-by: elaine.zhang <zhangqing@rock-chips.com>
Diagnosed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-03-22 15:21:38 +01:00
Rafael J. Wysocki 0cab893f40 Revert "PM: runtime: Update device status before letting suppliers suspend"
Revert commit 44cc89f764 ("PM: runtime: Update device status
before letting suppliers suspend") that introduced a race condition
into __rpm_callback() which allowed a concurrent rpm_resume() to
run and resume the device prematurely after its status had been
changed to RPM_SUSPENDED by __rpm_callback().

Fixes: 44cc89f764 ("PM: runtime: Update device status before letting suppliers suspend")
Link: https://lore.kernel.org/linux-pm/24dfb6fc-5d54-6ee2-9195-26428b7ecf8a@intel.com/
Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: 4.10+ <stable@vger.kernel.org> # 4.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2021-03-19 16:35:47 +01:00
Rafael J. Wysocki 44cc89f764 PM: runtime: Update device status before letting suppliers suspend
Because the PM-runtime status of the device is not updated in
__rpm_callback(), attempts to suspend the suppliers of the given
device triggered by rpm_put_suppliers() called by it may fail.

Fix this by making __rpm_callback() update the device's status to
RPM_SUSPENDED before calling rpm_put_suppliers() if the current
status of the device is RPM_SUSPENDING and the callback just invoked
by it has returned 0 (success).

While at it, modify the code in __rpm_callback() to always check
the device's PM-runtime status under its PM lock.

Link: https://lore.kernel.org/linux-pm/CAPDyKFqm06KDw_p8WXsM4dijDbho4bb6T4k50UqqvR1_COsp8g@mail.gmail.com/
Fixes: 21d5c57b37 ("PM / runtime: Use device links")
Reported-by: Elaine Zhang <zhangqing@rock-chips.com>
Diagnosed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Elaine Zhang <zhangiqng@rock-chips.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: 4.10+ <stable@vger.kernel.org> # 4.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-03-01 17:40:38 +01:00
Bhaskar Chowdhury 10aa694ea0 PM: runtime: Fix resposible -> responsible in runtime.c
s/resposible/responsible/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
[ rjw: Subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-01-22 16:51:15 +01:00
Rafael J. Wysocki d6e3666859 PM: runtime: Drop pm_runtime_clean_up_links()
After commit d12544fb2a ("PM: runtime: Remove link state checks in
rpm_get/put_supplier()") nothing prevents the consumer device's
runtime PM from acquiring additional references to the supplier
device after pm_runtime_clean_up_links() has run (or even while it
is running), so calling this function from __device_release_driver()
may be pointless (or even harmful).

Moreover, it ignores stateless device links, so the runtime PM
handling of managed and stateless device links is inconsistent
because of it, so better get rid of it entirely.

Fixes: d12544fb2a ("PM: runtime: Remove link state checks in rpm_get/put_supplier()")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 5.1+ <stable@vger.kernel.org> # 5.1+
Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-02 18:14:07 +01:00
Rafael J. Wysocki e0e398e204 PM: runtime: Drop runtime PM references to supplier on link removal
While removing a device link, drop the supplier device's runtime PM
usage counter as many times as needed to drop all of the runtime PM
references to it from the consumer in addition to dropping the
consumer's link count.

Fixes: baa8809f60 ("PM / runtime: Optimize the use of device links")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 5.1+ <stable@vger.kernel.org> # 5.1+
Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-02 18:14:07 +01:00
Xiang Chen d12544fb2a PM: runtime: Remove link state checks in rpm_get/put_supplier()
To support runtime PM for hisi SAS driver (the driver is in directory
drivers/scsi/hisi_sas), we add device link between scsi_device->sdev_gendev
(consumer device) and hisi_hba->dev(supplier device) with flags
DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE.

After runtime suspended consumers and supplier, unload the dirver which
causes a hung.

We found that it called function device_release_driver_internal() to
release the supplier device (hisi_hba->dev), as the device link was
busy, it set the device link state to DL_STATE_SUPPLIER_UNBIND, and
then it called device_release_driver_internal() to release the consumer
device (scsi_device->sdev_gendev).

Then it would try to call pm_runtime_get_sync() to resume the consumer
device, but because consumer-supplier relation existed, it would try
to resume the supplier first, but as the link state was already
DL_STATE_SUPPLIER_UNBIND, so it skipped resuming the supplier and only
resumed the consumer which hanged (it sends IOs to resume scsi_device
while the SAS controller is suspended).

Simple flow is as follows:

device_release_driver_internal -> (supplier device)
    if device_links_busy ->
	device_links_unbind_consumers ->
	    ...
	    WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND)
	    device_release_driver_internal (consumer device)
    pm_runtime_get_sync -> (consumer device)
	...
	__rpm_callback ->
	    rpm_get_suppliers ->
		if link->state == DL_STATE_SUPPLIER_UNBIND -> skip the action of resuming the supplier
		...
    pm_runtime_clean_up_links
    ...

Correct suspend/resume ordering between a supplier device and its consumer
devices (resume the supplier device before resuming consumer devices, and
suspend consumer devices before suspending the supplier device) should be
guaranteed by runtime PM, but the state checks in rpm_get_supplier() and
rpm_put_supplier() break this rule, so remove them.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
[ rjw: Subject and changelog edits ]
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-09-25 17:00:47 +02:00
Rafael J. Wysocki 0abf803ef1 PM: runtime: Improve kerneldoc of pm_runtime_get_if_active()
The kerneldoc comment of pm_runtime_get_if_active() doesn't list the
second argument of the function properly, so fix that and while at it
clarify that comment somewhat and add some markup to it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
2020-08-04 12:40:10 +02:00
Andy Shevchenko 3618bbaaa8 PM: runtime: Make clear what we do when conditions are wrong in rpm_suspend()
rpm_suspend() simple bails out when conditions are wrong. But this is not
immediately obvious from the code.  Make it clear what we do when conditions
are wrong in rpm_suspend().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-25 10:54:39 +02:00
Sakari Ailus c111566bea PM: runtime: Add pm_runtime_get_if_active()
pm_runtime_get_if_in_use() bumps up the PM-runtime usage count if it
is not equal to zero and the device's PM-runtime status is 'active'.
This works for drivers that do not use autoidle, but for those that
do, the function returns zero even when the device is active.

In order to maintain sane device state while the device is powered on
in the hope that it'll be needed, pm_runtime_get_if_active(dev, true)
returns a positive value if the device's PM-runtime status is 'active'
when it is called, in which case it also increments the device's usage
count.

If the second argument of pm_runtime_get_if_active() is 'false', the
function behaves just like pm_runtime_get_if_in_use(), so redefine
the latter as a wrapper around the former.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-03-04 11:01:18 +01:00
Michał Mirosław d229290689 PM-runtime: add tracepoints for usage_count changes
Add tracepoints to remaining places where device's power.usage_count
is changed.

This helps debugging where and why autosuspend is prevented.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-01-13 12:28:29 +01:00
Linus Torvalds 1f7d290a72 Driver core patches for 5.4-rc1
Here is the big driver core update for 5.4-rc1.
 
 There was a bit of a churn in here, with a number of core and OF
 platform patches being added to the tree, and then after much discussion
 and review and a day-long in-person meeting, they were decided to be
 reverted and a new set of patches is currently being reviewed on the
 mailing list.
 
 Other than that churn, there are two "persistent" branches in here that
 other trees will be pulling in as well during the merge window.  One
 branch to add support for drivers to have the driver core automatically
 add sysfs attribute files when a driver is bound to a device so that the
 driver doesn't have to manually do it (and then clean it up, as it
 always gets it wrong).
 
 There's another branch in here for generic lookup helpers for the driver
 core that lots of busses are starting to use.  That's the majority of
 the non-driver-core changes in this patch series.
 
 There's also some on-going debugfs file creation cleanup that has been
 slowly happening over the past few releases, with the goal to hopefully
 get that done sometime next year.
 
 All of these have been in linux-next for a while now with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg Kroah-Hartman:
 "Here is the big driver core update for 5.4-rc1.

  There was a bit of a churn in here, with a number of core and OF
  platform patches being added to the tree, and then after much
  discussion and review and a day-long in-person meeting, they were
  decided to be reverted and a new set of patches is currently being
  reviewed on the mailing list.

  Other than that churn, there are two "persistent" branches in here
  that other trees will be pulling in as well during the merge window.
  One branch to add support for drivers to have the driver core
  automatically add sysfs attribute files when a driver is bound to a
  device so that the driver doesn't have to manually do it (and then
  clean it up, as it always gets it wrong).

  There's another branch in here for generic lookup helpers for the
  driver core that lots of busses are starting to use. That's the
  majority of the non-driver-core changes in this patch series.

  There's also some on-going debugfs file creation cleanup that has been
  slowly happening over the past few releases, with the goal to
  hopefully get that done sometime next year.

  All of these have been in linux-next for a while now with no reported
  issues"

[ Note that the above-mentioned generic lookup helpers branch was
  already brought in by the LED merge (commit 4feaab05dc) that had
  shared it.

  Also note that that common branch introduced an i2c bug due to a bad
  conversion, which got fixed here. - Linus ]

* tag 'driver-core-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (49 commits)
  coccinelle: platform_get_irq: Fix parse error
  driver-core: add include guard to linux/container.h
  sysfs: add BIN_ATTR_WO() macro
  driver core: platform: Export platform_get_irq_optional()
  hwmon: pwm-fan: Use platform_get_irq_optional()
  driver core: platform: Introduce platform_get_irq_optional()
  Revert "driver core: Add support for linking devices during device addition"
  Revert "driver core: Add edit_links() callback for drivers"
  Revert "of/platform: Add functional dependency link from DT bindings"
  Revert "driver core: Add sync_state driver/bus callback"
  Revert "of/platform: Pause/resume sync state during init and of_platform_populate()"
  Revert "of/platform: Create device links for all child-supplier depencencies"
  Revert "of/platform: Don't create device links for default busses"
  Revert "of/platform: Fix fn definitons for of_link_is_valid() and of_link_property()"
  Revert "of/platform: Fix device_links_supplier_sync_state_resume() warning"
  Revert "of/platform: Disable generic device linking code for PowerPC"
  devcoredump: fix typo in comment
  devcoredump: use memory_read_from_buffer
  of/platform: Disable generic device linking code for PowerPC
  device.h: Fix warnings for mismatched parameter names in comments
  ...
2019-09-18 10:04:39 -07:00
Joel Fernandes (Google) c2fa1e1bfa driver/core: Convert to use built-in RCU list checking
This commit applies the consolidated hlist_for_each_entry_rcu() support
for lockdep conditions.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2019-08-13 14:28:47 -07:00
Rafael J. Wysocki 515db266a9 driver core: Remove device link creation limitation
If device_link_add() is called for a consumer/supplier pair with an
existing device link between them and the existing link's type is
not in agreement with the flags passed to that function by its
caller, NULL will be returned.  That is seriously inconvenient,
because it forces the callers of device_link_add() to worry about
what others may or may not do even if that is not relevant to them
for any other reasons.

It turns out, however, that this limitation can be made go away
relatively easily.

The underlying observation is that if DL_FLAG_STATELESS has been
passed to device_link_add() in flags for the given consumer/supplier
pair at least once, calling either device_link_del() or
device_link_remove() to release the link returned by it should work,
but there are no other requirements associated with that flag.  In
turn, if at least one of the callers of device_link_add() for the
given consumer/supplier pair has not passed DL_FLAG_STATELESS to it
in flags, the driver core should track the status of the link and act
on it as appropriate (ie. the link should be treated as "managed").
This means that DL_FLAG_STATELESS needs to be set for managed device
links and it should be valid to call device_link_del() or
device_link_remove() to drop references to them in certain
sutiations.

To allow that to happen, introduce a new (internal) device link flag
called DL_FLAG_MANAGED and make device_link_add() set it automatically
whenever DL_FLAG_STATELESS is not passed to it.  Also make it take
additional references to existing device links that were previously
stateless (that is, with DL_FLAG_STATELESS set and DL_FLAG_MANAGED
unset) and will need to be managed going forward and initialize
their status (which has been DL_STATE_NONE so far).

Accordingly, when a managed device link is dropped automatically
by the driver core, make it clear DL_FLAG_MANAGED, reset the link's
status back to DL_STATE_NONE and drop the reference to it associated
with DL_FLAG_MANAGED instead of just deleting it right away (to
allow it to stay around in case it still needs to be released
explicitly by someone).

With that, since setting DL_FLAG_STATELESS doesn't mean that the
device link in question is not managed any more, replace all of the
status-tracking checks against DL_FLAG_STATELESS with analogous
checks against DL_FLAG_MANAGED and update the documentation to
reflect these changes.

While at it, make device_link_add() reject flags that it does not
recognize, including DL_FLAG_MANAGED.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Saravana Kannan <saravanak@google.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Review-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/2305283.AStDPdUUnE@kreacher
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-25 13:31:18 +02:00
Viresh Kumar 8262331eaa PM / QOS: Rename __dev_pm_qos_read_value() and dev_pm_qos_raw_read_value()
dev_pm_qos_read_value() will soon need to support more constraint types
(min/max frequency) and will have another argument to it, i.e. type of
the constraint. While that is fine for the existing users of
dev_pm_qos_read_value(), but not that optimal for the callers of
__dev_pm_qos_read_value() and dev_pm_qos_raw_read_value() as all the
callers of these two routines are only looking for resume latency
constraint.

Lets make these two routines care only about the resume latency
constraint and rename them to __dev_pm_qos_resume_latency() and
dev_pm_qos_raw_resume_latency().

Suggested-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-04 10:40:54 +02:00
Greg Kroah-Hartman 5de363b66a drivers: base: power: add proper SPDX identifiers on files that did not have them.
There were a few files in the driver core power code that did not have
SPDX identifiers on them, so fix that up.  At the same time, remove the
"free form" text that specified the license of the file, as that is
impossible for any tool to properly parse.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-04 20:03:40 +02:00
Linus Torvalds 9352ca585b Additional power management updates for 5.1-rc1
- Fix registration of new cpuidle governors partially broken during
    the 5.0 development cycle by mistake (Rafael Wysocki).
 
  - Avoid integer overflows in the menu cpuidle governor by making
    it discard the overflowing data points upfront (Rafael Wysocki).
 
  - Fix minor mistake in the recent update of the iowait boost
    computation in the intel_pstate driver (Rafael Wysocki).
 
  - Drop incorrect __init annotation from one function in the pxa2xx
    cpufreq driver (Arnd Bergmann).
 
  - Fix the operating performance points (OPP) framework
    initialization for devices in multiple power domains if
    only one of them is scalable (Rajendra Nayak).
 
  - Fix mistake in dev_pm_opp_set_rate() which causes it to skip
    updating the performance state if the new frequency is the same
    as the old one (Viresh Kumar).
 
  - Rework the cancellation of wakeup source timers to avoid
    potential issues with it and do some cleanups unlocked by
    that change (Viresh Kumar, Rafael Wysocki).
 
  - Clean up the code computing the active/suspended time of devices
    in the PM-runtime framework after recent changes (Ulf Hansson).
 
  - Make the power management infrastructure code use pr_fmt()
    consistently (Joe Perches).
 
  - Clean up the generic power domains (genpd) framework somewhat
    (Aisheng Dong).
 
  - Improve kerneldoc comments for two functions in the cpufreq core
    (Rafael Wysocki).
 
  - Fix typo in a PM QoS file description comment (Aisheng Dong).
 
  - Update the handling of CPU boost frequencies in the cpupower
    utility (Abhishek Goel).
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Merge tag 'pm-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more power management updates from Rafael Wysocki:
 "These are mostly fixes and cleanups on top of the previously merged
  power management material for 5.1-rc1 with one cpupower utility update
  that wasn't pushed earlier due to unfortunate timing.

  Specifics:

   - Fix registration of new cpuidle governors partially broken during
     the 5.0 development cycle by mistake (Rafael Wysocki).

   - Avoid integer overflows in the menu cpuidle governor by making it
     discard the overflowing data points upfront (Rafael Wysocki).

   - Fix minor mistake in the recent update of the iowait boost
     computation in the intel_pstate driver (Rafael Wysocki).

   - Drop incorrect __init annotation from one function in the pxa2xx
     cpufreq driver (Arnd Bergmann).

   - Fix the operating performance points (OPP) framework initialization
     for devices in multiple power domains if only one of them is
     scalable (Rajendra Nayak).

   - Fix mistake in dev_pm_opp_set_rate() which causes it to skip
     updating the performance state if the new frequency is the same as
     the old one (Viresh Kumar).

   - Rework the cancellation of wakeup source timers to avoid potential
     issues with it and do some cleanups unlocked by that change (Viresh
     Kumar, Rafael Wysocki).

   - Clean up the code computing the active/suspended time of devices in
     the PM-runtime framework after recent changes (Ulf Hansson).

   - Make the power management infrastructure code use pr_fmt()
     consistently (Joe Perches).

   - Clean up the generic power domains (genpd) framework somewhat
     (Aisheng Dong).

   - Improve kerneldoc comments for two functions in the cpufreq core
     (Rafael Wysocki).

   - Fix typo in a PM QoS file description comment (Aisheng Dong).

   - Update the handling of CPU boost frequencies in the cpupower
     utility (Abhishek Goel)"

* tag 'pm-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpuidle: governor: Add new governors to cpuidle_governors again
  cpufreq: intel_pstate: Fix up iowait_boost computation
  PM / OPP: Update performance state when freq == old_freq
  PM / wakeup: Drop wakeup_source_drop()
  PM / wakeup: Rework wakeup source timer cancellation
  PM / domains: Remove one unnecessary blank line
  PM / Domains: Return early for all errors in _genpd_power_off()
  PM / Domains: Improve warn for multiple states but no governor
  OPP: Fix handling of multiple power domains
  PM / QoS: Fix typo in file description
  cpufreq: pxa2xx: remove incorrect __init annotation
  PM-runtime: Call pm_runtime_active|suspended_time() from sysfs
  PM-runtime: Consolidate code to get active/suspended time
  PM: Add and use pr_fmt()
  cpufreq: Improve kerneldoc comments for cpufreq_cpu_get/put()
  cpuidle: menu: Avoid overflows when computing variance
  tools/power/cpupower: Display boost frequency separately
2019-03-14 10:30:06 -07:00
Ulf Hansson 0996584b30 PM-runtime: Call pm_runtime_active|suspended_time() from sysfs
Avoid the open-coding of the accounted time acquisition in
runtime_active|suspend_time_show() and make them call
pm_runtime_active|suspended_time() instead.

Note that this change also indirectly avoids holding dev->power.lock
around the do_div() computation and the sprintf() call which is an
additional improvement.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-03-07 11:23:17 +01:00
Ulf Hansson fdc56c0732 PM-runtime: Consolidate code to get active/suspended time
In a step to consolidate the code for fetching the PM-runtime
active/suspended time for a device, add a common function for that
and make the existing pm_runtime_suspended_time() call it.

Also add a corresponding pm_runtime_active_time() calling the new
common function.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Changelog, function rename ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-03-07 11:23:17 +01:00
Linus Torvalds e431f2d74e Driver core patches for 5.1-rc1
Here is the big driver core patchset for 5.1-rc1
 
 More patches than "normal" here this merge window, due to some work in
 the driver core by Alexander Duyck to rework the async probe
 functionality to work better for a number of devices, and independant
 work from Rafael for the device link functionality to make it work
 "correctly".
 
 Also in here is:
 	- lots of BUS_ATTR() removals, the macro is about to go away
 	- firmware test fixups
 	- ihex fixups and simplification
 	- component additions (also includes i915 patches)
 	- lots of minor coding style fixups and cleanups.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the big driver core patchset for 5.1-rc1

  More patches than "normal" here this merge window, due to some work in
  the driver core by Alexander Duyck to rework the async probe
  functionality to work better for a number of devices, and independant
  work from Rafael for the device link functionality to make it work
  "correctly".

  Also in here is:

   - lots of BUS_ATTR() removals, the macro is about to go away

   - firmware test fixups

   - ihex fixups and simplification

   - component additions (also includes i915 patches)

   - lots of minor coding style fixups and cleanups.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (65 commits)
  driver core: platform: remove misleading err_alloc label
  platform: set of_node in platform_device_register_full()
  firmware: hardcode the debug message for -ENOENT
  driver core: Add missing description of new struct device_link field
  driver core: Fix PM-runtime for links added during consumer probe
  drivers/component: kerneldoc polish
  async: Add cmdline option to specify drivers to be async probed
  driver core: Fix possible supplier PM-usage counter imbalance
  PM-runtime: Fix __pm_runtime_set_status() race with runtime resume
  driver: platform: Support parsing GpioInt 0 in platform_get_irq()
  selftests: firmware: fix verify_reqs() return value
  Revert "selftests: firmware: remove use of non-standard diff -Z option"
  Revert "selftests: firmware: add CONFIG_FW_LOADER_USER_HELPER_FALLBACK to config"
  device: Fix comment for driver_data in struct device
  kernfs: Allocating memory for kernfs_iattrs with kmem_cache.
  sysfs: remove unused include of kernfs-internal.h
  driver core: Postpone DMA tear-down until after devres release
  driver core: Document limitation related to DL_FLAG_RPM_ACTIVE
  PM-runtime: Take suppliers into account in __pm_runtime_set_status()
  device.h: Add __cold to dev_<level> logging functions
  ...
2019-03-06 14:52:48 -08:00
Rafael J. Wysocki 656f72bb2e Merge back earlier PM core material for v5.1. 2019-02-24 21:20:27 +01:00
Vincent Guittot 74fb448630 PM-runtime: Fix deadlock when canceling hrtimer
When rpm_resume() desactivates the autosuspend timer, it should only
try to cancel hrtimer but not wait for the handler to finish, because
both rpm_resume() and pm_suspend_timer_fn() take the power.lock.

A deadlock is possible as follows:

CPU0                              CPU1
rpm_resume()
  spin_lock_irqsave
                                  pm_suspend_timer_fn()
                                    spin_lock_irqsave
  pm_runtime_deactivate_timer()
    hrtimer_cancel()

It is sufficient to call hrtimer_try_to_cancel() from
pm_runtime_deactivate_timer(), because dev->power.timer_expires
reset to 0 by it, so use that function instead of hrtimer_cancel().

Fixes: 8234f6734c ("PM-runtime: Switch autosuspend over to using hrtimers")
Reported-by: Sunzhaosheng Sun(Zhaosheng) <sunzhaosheng@hisilicon.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-02-21 10:29:00 +01:00
Rafael J. Wysocki 36003d4cf5 driver core: Fix PM-runtime for links added during consumer probe
Commit 4c06c4e6cf ("driver core: Fix possible supplier PM-usage
counter imbalance") introduced a regression that causes suppliers
to be suspended prematurely for device links added during consumer
driver probe if the initial PM-runtime status of the consumer is
"suspended" and the consumer is resumed after adding the link and
before pm_runtime_put_suppliers() is called.  In that case,
pm_runtime_put_suppliers() will drop the rpm_active refcount for
the link by one and (since rpm_active is equal to two after the
preceding consumer resume) the supplier's PM-runtime usage counter
will be decremented, which may cause the supplier to suspend even
though the consumer's PM-runtime status is "active".

For this reason, partially revert commit 4c06c4e6cf as the problem
it tried to fix needs to be addressed somewhat differently, and
change pm_runtime_get_suppliers() and pm_runtime_put_suppliers() so
that the latter only drops rpm_active references acquired by the
former.  [This requires adding a new field to struct device_link,
but I coulnd't find a cleaner way to address the issue that would
work in all cases.]

This causes pm_runtime_put_suppliers() to effectively ignore device
links added during consumer probe, so device_link_add() doesn't need
to worry about ensuring that suppliers will remain active after
pm_runtime_put_suppliers() for links created with DL_FLAG_RPM_ACTIVE
set and it only needs to bump up rpm_active by one for those links,
so pm_runtime_active_link() is not necessary any more.

Fixes: 4c06c4e6cf ("driver core: Fix possible supplier PM-usage counter imbalance")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-20 11:18:07 +01:00
Rafael J. Wysocki 4c06c4e6cf driver core: Fix possible supplier PM-usage counter imbalance
If a stateless device link to a certain supplier with
DL_FLAG_PM_RUNTIME set in the flags is added and then removed by the
consumer driver's probe callback, the supplier's PM-runtime usage
counter will be nonzero after that which effectively causes the
supplier to remain "always on" going forward.

Namely, device_link_add() called to add the link invokes
device_link_rpm_prepare() which notices that the consumer driver is
probing, so it increments the supplier's PM-runtime usage counter
with the assumption that the link will stay around until
pm_runtime_put_suppliers() is called by driver_probe_device(),
but if the link goes away before that point, the supplier's
PM-runtime usage counter will remain nonzero.

To prevent that from happening, first rework pm_runtime_get_suppliers()
and pm_runtime_put_suppliers() to use the rpm_active refounts of device
links and make the latter only drop rpm_active and the supplier's
PM-runtime usage counter for each link by one, unless rpm_active is
one already for it.  Next, modify device_link_add() to bump up the
new link's rpm_active refcount and the suppliers PM-runtime usage
counter by two, to prevent pm_runtime_put_suppliers(), if it is
called subsequently, from suspending the supplier prematurely (in
case its PM-runtime usage counter goes down to 0 in there).

Due to the way rpm_put_suppliers() works, this change does not
affect runtime suspend of the consumer ends of new device links (or,
generally, device links for which DL_FLAG_PM_RUNTIME has just been
set).

Fixes: e2f3cd831a ("driver core: Fix handling of runtime PM flags in device_link_add()")
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-13 09:09:57 +01:00
Rafael J. Wysocki c1567f813a PM-runtime: Fix __pm_runtime_set_status() race with runtime resume
Commit 4080ab0830 ("PM-runtime: Take suppliers into account in
__pm_runtime_set_status()") introduced a race condition that may
trigger if __pm_runtime_set_status() is used incorrectly (that is,
if it is called when PM-runtime is enabled for the target device
and working).

In that case, if the original PM-runtime status of the device is
RPM_SUSPENDED, a runtime resume of the device may occur after
__pm_runtime_set_status() has dropped its power.lock spinlock
and before deactivating its suppliers, so the suppliers may be
deactivated while the device is PM-runtime-active which may lead
to functional issues.

To avoid that, modify __pm_runtime_set_status() to check whether
or not PM-runtime is enabled for the device before activating its
suppliers (if the new status is RPM_ACTIVE) and either return an
error if that's the case or increment the device's disable_depth
counter to prevent PM-runtime from being enabled for it while
the remaining part of the function is running (disable_depth is
then decremented on the way out).

Fixes: 4080ab0830 ("PM-runtime: Take suppliers into account in __pm_runtime_set_status()")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-13 09:09:51 +01:00