[PATCH v2 5/5] cpuidle: psci: Prevent domain idlestates until consumers are ready
From: Ulf Hansson <hidden>
Date: 2020-07-07 13:00:20
Also in:
linux-pm
Subsystem:
cpu idle time management framework, cpuidle driver - arm psci pm domain, the rest · Maintainers:
"Rafael J. Wysocki", Daniel Lezcano, Ulf Hansson, Linus Torvalds
Depending on the SoC/platform, additional devices may be part of the PSCI PM domain topology. This is the case with 'qcom,rpmh-rsc' device, for example, even if this is not yet visible in the corresponding DTS-files. Without going into too much details, a device like the 'qcom,rpmh-rsc' may have HW constraints that needs to be obeyed to, before a domain idlestate can be picked. Therefore, let's implement the ->sync_state() callback to receive a notification when all consumers of the PSCI PM domain providers have been attached/probed to it. In this way, we can make sure all constraints from all relevant devices, are taken into account before allowing a domain idlestate to be picked. Acked-by: Saravana Kannan <redacted> Signed-off-by: Ulf Hansson <redacted> --- drivers/cpuidle/cpuidle-psci-domain.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c
index bf527d2bb4b6..b6e9649ab0da 100644
--- a/drivers/cpuidle/cpuidle-psci-domain.c
+++ b/drivers/cpuidle/cpuidle-psci-domain.c@@ -27,6 +27,7 @@ struct psci_pd_provider { }; static LIST_HEAD(psci_pd_providers); +static bool psci_pd_allow_domain_state; static int psci_pd_power_off(struct generic_pm_domain *pd) {
@@ -36,6 +37,9 @@ static int psci_pd_power_off(struct generic_pm_domain *pd) if (!state->data) return 0; + if (!psci_pd_allow_domain_state) + return -EBUSY; + /* OSI mode is enabled, set the corresponding domain state. */ pd_state = state->data; psci_set_domain_state(*pd_state);
@@ -222,6 +226,15 @@ static void psci_pd_remove_topology(struct device_node *np) psci_pd_init_topology(np, false); } +static void psci_cpuidle_domain_sync_state(struct device *dev) +{ + /* + * All devices have now been attached/probed to the PM domain topology, + * hence it's fine to allow domain states to be picked. + */ + psci_pd_allow_domain_state = true; +} + static const struct of_device_id psci_of_match[] = { { .compatible = "arm,psci-1.0" }, {}
@@ -289,6 +302,7 @@ static struct platform_driver psci_cpuidle_domain_driver = { .driver = { .name = "psci-cpuidle-domain", .of_match_table = psci_of_match, + .sync_state = psci_cpuidle_domain_sync_state, }, };
--
2.20.1
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