linux/drivers/base/power/runtime.c, branch v6.0

PM: runtime: Extend support for wakeirq for force_suspend|resume

2022-07-08T19:29:06Z

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 Reviewed-by: Tony Lindgren Signed-off-by: Rafael J. Wysocki

PM: runtime: Fix supplier device management during consumer probe

2022-07-01T19:04:15Z

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 4c06c4e6cf63 ("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: 4c06c4e6cf63 ("driver core: Fix possible supplier PM-usage counter imbalance") Reported-by: Peter Wang Signed-off-by: Rafael J. Wysocki Reviewed-by: Greg Kroah-Hartman Reviewed-by: Peter Wang Cc: 5.1+ # 5.1+

PM: runtime: Redefine pm_runtime_release_supplier()

2022-07-01T19:04:02Z

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 Signed-off-by: Rafael J. Wysocki Reviewed-by: Greg Kroah-Hartman Cc: 5.1+ # 5.1+

Merge branches 'pm-core', 'pm-sleep' and 'powercap'

2022-05-23T17:06:33Z

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

PM: runtime: Allow to call __pm_runtime_set_status() from atomic context

2022-04-19T15:24:02Z

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 Tested-by: Maulik Shah Signed-off-by: Rafael J. Wysocki

PM: runtime: Avoid device usage count underflows

2022-04-13T15:30:32Z

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 Reviewed-by: Ulf Hansson

PM: runtime: Have devm_pm_runtime_enable() handle pm_runtime_dont_use_autosuspend()

2022-03-04T17:26:54Z

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 Signed-off-by: Douglas Anderson Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM: runtime: Simplify locking in pm_runtime_put_suppliers()

2021-12-22T17:37:55Z

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 Reviewed-by: Ulf Hansson

PM: runtime: Add safety net to supplier device release

2021-12-17T15:25:14Z

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: Capture device status before disabling runtime PM

2021-12-17T15:16:40Z

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 Signed-off-by: Rafael J. Wysocki