kernel/linux.git/include/linux/pm_domain.h, branch v6.6.132

PM: domains: Allow a genpd consumer to require a synced power off

2023-01-10T17:07:10+00:00

Some genpd providers doesn't ensure that it has turned off at hardware. This is fine until the consumer really requires during some special scenarios that the power domain collapse at hardware before it is turned ON again. An example is the reset sequence of Adreno GPU which requires that the 'gpucc cx gdsc' power domain should move to OFF state in hardware at least once before turning in ON again to clear the internal state. Signed-off-by: Ulf Hansson Signed-off-by: Akhil P Oommen Reviewed-by: Bjorn Andersson Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20230102161757.v5.1.I3e6b1f078ad0f1ca9358c573daa7b70ec132cdbe@changeid

PM: domains: Store the next hrtimer wakeup in genpd

2022-11-10T03:14:21+00:00

The arch timer cannot wake up the Qualcomm Technologies, Inc. (QTI) SoCs from the deeper CPUidle states. To be able to wakeup from these deeper states, another always-on timer needs to be programmed through the so called CONTROL_TCS. As the RSC is part of CPU subsystem and the corresponding APSS RSC device is attached to the cluster PM domain (through genpd), it holds the responsibility to program the always-on timer, before entering any of these deeper CPUidle states. However, programming the timer requires information about the next hrtimer wakeup for the cluster PM domain, which is currently only known by genpd. Therefore, let's share this data through a new genpd helper function, dev_pm_genpd_get_next_hrtimer(). Signed-off-by: Maulik Shah Cc: "Rafael J. Wysocki" [Ulf: Reworked the code and updated the commit message] Signed-off-by: Ulf Hansson Tested-by: Dmitry Baryshkov # SM8450 Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20221018152837.619426-5-ulf.hansson@linaro.org

PM: domains: Allocate governor data dynamically based on a genpd governor

2022-05-19T18:16:05+00:00

If a genpd doesn't have an associated governor assigned, several variables in the struct generic_pm_domain becomes superfluous. Rather than wasting memory in allocated genpds, let's move the variables from the struct generic_pm_domain into a new separate struct. In this way, we can instead dynamically decide when we need to allocate the corresponding data for it. Signed-off-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM: domains: Move the next_wakeup variable into the struct gpd_timing_data

2022-05-19T18:16:05+00:00

If the corresponding genpd for the device doesn't use a governor, the variable next_wakeup within the struct generic_pm_domain_data becomes superfluous. To avoid wasting memory, let's move it into the struct gpd_timing_data, which is already being allocated based upon if there is governor assigned. Signed-off-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM: domains: Allocate gpd_timing_data dynamically based on governor

2022-05-19T18:16:05+00:00

If a genpd doesn't have an associated governor assigned, there's really no point to allocate the per device gpd_timing_data, as the data isn't being used by a governor anyway. To avoid wasting memory, let's therefore convert the corresponding td variable in the struct generic_pm_domain_data into a pointer and manage the allocation of its data dynamically. Signed-off-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM: domains: Move genpd's time-accounting to ktime_get_mono_fast_ns()

2022-04-22T14:11:25+00:00

To move towards a more consistent behaviour between genpd and the runtime PM core, let's start by converting genpd's time-accounting from ktime_get() into ktime_get_mono_fast_ns(). Signed-off-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM: domains: Add support for 'required-opps' to set default perf state

2021-08-16T16:45:29+00:00

Some devices within power domains with performance states do not support DVFS, but still need to vote on a default/static state while they are active. They can express this using the 'required-opps' property in device tree, which points to the phandle of the OPP supported by the corresponding power-domains. Add support to parse this information from DT and then set the specified performance state during attach and drop it on detach. runtime suspend/resume callbacks already have logic to drop/set the vote as needed and should take care of dropping the default perf state vote on runtime suspend and restore it back on runtime resume. Signed-off-by: Rajendra Nayak Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM: domains: Drop/restore performance state votes for devices at runtime PM

2021-06-11T16:39:24+00:00

A subsystem/driver that need to manage OPPs for its device, should typically drop its vote for the OPP when the device becomes runtime suspended. In this way, the corresponding aggregation of the performance state votes that is managed in genpd for the attached PM domain, may find that the aggregated vote can be decreased. Hence, it may allow genpd to set the lower performance state for the PM domain, thus avoiding to waste energy. To accomplish this, typically a subsystem/driver would need to call dev_pm_opp_set_rate|opp() for its device from its ->runtime_suspend() callback, to drop the vote for the OPP. Accordingly, it needs another call to dev_pm_opp_set_rate|opp() to restore the vote for the OPP from its ->runtime_resume() callback. To avoid boilerplate code in subsystems/driver to deal with these things, let's instead manage this internally in genpd. Signed-off-by: Ulf Hansson Tested-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki

PM: domains: use device's next wakeup to determine domain idle state

2021-01-22T16:08:28+00:00

Currently, a PM domain's idle state is determined based on whether the QoS requirements are met. However, even entering an idle state may waste power if the minimum residency requirements aren't fulfilled. CPU PM domains use the next timer wakeup for the CPUs in the domain to determine the sleep duration of the domain. This is compared with the idle state residencies to determine the optimal idle state. For other PM domains, determining the sleep length is not that straight forward. But if the device's next_event is available, we can use that to determine the sleep duration of the PM domain. Let's update the domain governor logic to check for idle state residency based on the next wakeup of devices as well as QoS constraints. But since, not all domains may contain devices capable of specifying the next wakeup, let's enable this additional check only if specified by the domain's flags when initializing the domain. Signed-off-by: Lina Iyer Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM: domains: inform PM domain of a device's next wakeup

2021-01-22T16:08:27+00:00

Some devices may have a predictable interrupt pattern while executing usecases. An example would be the VSYNC interrupt associated with display devices. A 60 Hz display could cause a interrupt every 16 ms. If the device were in a PM domain, the domain would need to be powered up for device to resume and handle the interrupt. Entering a domain idle state saves power, only if the residency of the idle state is met. Without knowing the idle duration of the domain, the governor would just choose the deepest idle state that matches the QoS requirements. The domain might be powered off just as the device is expecting to wake up. If devices could inform PM frameworks of their next event, the parent PM domain's idle duration can be determined. So let's add the dev_pm_genpd_set_next_wakeup() API for the device to inform PM domains of the impending wakeup. This information will be the domain governor to determine the best idle state given the wakeup. Signed-off-by: Lina Iyer Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki