linux-toradex.git/include/linux/pm_runtime.h, branch v5.17-rc5

PM: runtime: Add EXPORT[_GPL]_RUNTIME_DEV_PM_OPS macros

2022-01-12T18:59:05+00:00

Similar to EXPORT[_GPL]_SIMPLE_DEV_PM_OPS, but for users with runtime-PM
suspend/resume callbacks.

Signed-off-by: Paul Cercueil 
Acked-by: Jonathan Cameron 
Reviewed-by: Ulf Hansson 
Signed-off-by: Rafael J. Wysocki

PM: runtime: Add DEFINE_RUNTIME_DEV_PM_OPS() macro

2022-01-12T18:59:05+00:00

A lot of drivers create a dev_pm_ops struct with the system sleep
suspend/resume callbacks set to pm_runtime_force_suspend() and
pm_runtime_force_resume().

These drivers can now use the DEFINE_RUNTIME_DEV_PM_OPS() macro, which
will use pm_runtime_force_{suspend,resume}() as the system sleep
callbacks, while having the same dead code removal characteristic that
is already provided by DEFINE_SIMPLE_DEV_PM_OPS().

Signed-off-by: Paul Cercueil 
Acked-by: Jonathan Cameron 
Reviewed-by: Ulf Hansson 
Signed-off-by: Rafael J. Wysocki

PM: runtime: Add safety net to supplier device release

2021-12-17T15:25:14+00:00

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 
Signed-off-by: Rafael J. Wysocki 
Acked-by: Greg Kroah-Hartman 
Acked-by: Peter Zijlstra (Intel)

PM: runtime: Fix pm_runtime_active() kerneldoc comment

2021-12-08T14:21:55+00:00

The kerneldoc comment of pm_runtime_active() does not reflect the
behavior of the function, so update it accordingly.

Fixes: 403d2d116ec0 ("PM: runtime: Add kerneldoc comments to multiple helpers")
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Ulf Hansson

PM: runtime: add devm_pm_runtime_enable helper

2021-08-26T18:27:51+00:00

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 
Link: https://lore.kernel.org/r/20210731195034.979084-2-dmitry.baryshkov@linaro.org
Acked-by: Rafael J. Wysocki 
Signed-off-by: Stephen Boyd

PM: runtime: document common mistake with pm_runtime_get_sync()

2021-05-31T12:17:13+00:00

pm_runtime_get_sync(), contradictory to intuition, does not drop the
runtime PM usage counter on errors which lead to several wrong usages in
drivers (missing the put).  pm_runtime_resume_and_get() was added as a
better implementation so document the preference of using it, hoping it
will stop bad patterns.

Suggested-by: Marek Szyprowski 
Signed-off-by: Krzysztof Kozlowski 
[ rjw: Documentation change edits ]
Signed-off-by: Rafael J. Wysocki

PM: runtime: Replace inline function pm_runtime_callbacks_present()

2021-04-08T17:14:46+00:00

Commit 9a7875461fd0 ("PM: runtime: Replace pm_runtime_callbacks_present()")
forgot to change the inline version.

Fixes: 9a7875461fd0 ("PM: runtime: Replace pm_runtime_callbacks_present()")
Signed-off-by: YueHaibing 
Signed-off-by: Rafael J. Wysocki

PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter

2020-11-16T17:37:01+00:00

In many case, we need to check return value of pm_runtime_get_sync, but
it brings a trouble to the usage counter processing. Many callers forget
to decrease the usage counter when it failed, which could resulted in
reference leak. It has been discussed a lot[0][1]. So we add a function
to deal with the usage counter for better coding.

[0]https://lkml.org/lkml/2020/6/14/88
[1]https://patchwork.ozlabs.org/project/linux-tegra/list/?series=178139
Signed-off-by: Zhang Qilong 
Acked-by: Rafael J. Wysocki  
Signed-off-by: Jakub Kicinski

PM: runtime: Drop pm_runtime_clean_up_links()

2020-11-02T17:14:07+00:00

After commit d12544fb2aa9 ("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: d12544fb2aa9 ("PM: runtime: Remove link state checks in rpm_get/put_supplier()")
Signed-off-by: Rafael J. Wysocki 
Cc: 5.1+  # 5.1+
Tested-by: Xiang Chen 
Reviewed-by: Greg Kroah-Hartman

PM: runtime: Drop runtime PM references to supplier on link removal

2020-11-02T17:14:07+00:00

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: baa8809f6097 ("PM / runtime: Optimize the use of device links")
Signed-off-by: Rafael J. Wysocki 
Cc: 5.1+  # 5.1+
Tested-by: Xiang Chen 
Reviewed-by: Greg Kroah-Hartman