kernel/linux.git/drivers/base/power/runtime.c, branch v6.2.6

PM: runtime: Adjust white space in the core code

2022-12-07T17:23:32+00:00

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

PM: runtime: Relocate rpm_callback() right after __rpm_callback()

2022-12-05T14:43:37+00:00

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 Reviewed-by: Adrian Hunter

PM: runtime: Do not call __rpm_callback() from rpm_idle()

2022-12-05T14:43:37+00:00

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: 21d5c57b3726 ("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 Reviewed-by: Adrian Hunter

PM: runtime: Return -EINPROGRESS from rpm_resume() in the RPM_NOWAIT case

2022-09-24T17:28:51+00:00

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 Acked-by: Alan Stern Reviewed-by: Douglas Anderson Reviewed-by: Ulf Hansson

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

2022-07-08T19:29:06+00:00

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

2022-07-01T19:04:15+00:00

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()

2022-07-01T19:04:02+00:00

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'

2022-05-23T17:06:33+00:00

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

2022-04-19T15:24:02+00:00

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

2022-04-13T15:30:32+00:00

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