Commit 1c4b2932 authored by Ulf Hansson's avatar Ulf Hansson
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cpuidle: psci: Enable the hierarchical topology for s2idle on PREEMPT_RT 



To enable the domain-idle-states to be used during s2idle on a PREEMPT_RT
based configuration, let's allow the re-assignment of the ->enter_s2idle()
callback to psci_enter_s2idle_domain_idle_state().

Similar to s2ram, let's leave the support for CPU hotplug outside
PREEMPT_RT, as it's depending on using runtime PM. For s2idle, this means
that an offline CPU's PM domain will remain powered-on. In practise this
may lead to that a shallower idle-state than necessary gets selected, which
shouldn't be an issue (besides wasting power).

Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Tested-by: Raghavendra Kakarla <quic_rkakarla@quicinc.com>  # qcm6490 with PREEMPT_RT set
Acked-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240527142557.321610-8-ulf.hansson@linaro.org
parent 4517b1c3

drivers/cpuidle/cpuidle-psci.c

+6 −7
Original line number Diff line number Diff line
@@ -233,18 +233,17 @@ static int psci_dt_cpu_init_topology(struct cpuidle_driver *drv, 


	psci_cpuidle_use_syscore = true;



	/* The hierarchical topology is limited to s2ram on PREEMPT_RT. */

	if (IS_ENABLED(CONFIG_PREEMPT_RT))

		return 0;



	/*

	 * Using the deepest state for the CPU to trigger a potential selection

	 * of a shared state for the domain, assumes the domain states are all

	 * deeper states.

	 * deeper states. On PREEMPT_RT the hierarchical topology is limited to

	 * s2ram and s2idle.

	 */

	drv->states[state_count - 1].enter = psci_enter_domain_idle_state;

	drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;

	if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {

		drv->states[state_count - 1].enter = psci_enter_domain_idle_state;

		psci_cpuidle_use_cpuhp = true;

	}



	return 0;

}