| Message ID | 20220401141124.27272-3-ulf.hansson@linaro.org |
|---|---|
| State | Accepted |
| Commit | 171b66e2e2e9d80b93c8cff799e6175074b22297 |
| Headers | show |
| Series | PM: runtime/cpuidle: Improve suspend-to-ram support for cpuidle-psci | expand |
Hi, On 4/1/2022 7:41 PM, Ulf Hansson wrote: > When PSCI OSI mode is supported the syscore flag is set for the CPU devices > that becomes attached to their PM domains (genpds). In the suspend-to-idle > case, we call dev_pm_genpd_suspend|resume() to allow genpd to properly > manage the power-off/on operations (pick an idlestate and manage the on/off > notifications). > > For suspend-to-ram, dev_pm_genpd_suspend|resume() is currently not being > called, which causes a problem that the genpd on/off notifiers do not get > sent as expected. This prevents the platform-specific operations from being > executed, typically needed just before/after the boot CPU is being turned > off/on. > > To deal with this problem, let's register a syscore ops for cpuidle-psci > when PSCI OSI mode is being used and call dev_pm_genpd_suspend|resume() > from them. In this way, genpd regains control of the PM domain topology and > then sends the on/off notifications when it's appropriate. > > Reported-by: Maulik Shah <quic_mkshah@quicinc.com> > Suggested-by: Maulik Shah <quic_mkshah@quicinc.com> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Maulik Shah <quic_mkshah@quicinc.com> Thanks, Maulik
diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c index b51b5df08450..540105ca0781 100644 --- a/drivers/cpuidle/cpuidle-psci.c +++ b/drivers/cpuidle/cpuidle-psci.c @@ -23,6 +23,7 @@ #include <linux/pm_runtime.h> #include <linux/slab.h> #include <linux/string.h> +#include <linux/syscore_ops.h> #include <asm/cpuidle.h> @@ -131,6 +132,49 @@ static int psci_idle_cpuhp_down(unsigned int cpu) return 0; } +static void psci_idle_syscore_switch(bool suspend) +{ + bool cleared = false; + struct device *dev; + int cpu; + + for_each_possible_cpu(cpu) { + dev = per_cpu_ptr(&psci_cpuidle_data, cpu)->dev; + + if (dev && suspend) { + dev_pm_genpd_suspend(dev); + } else if (dev) { + dev_pm_genpd_resume(dev); + + /* Account for userspace having offlined a CPU. */ + if (pm_runtime_status_suspended(dev)) + pm_runtime_set_active(dev); + + /* Clear domain state to re-start fresh. */ + if (!cleared) { + psci_set_domain_state(0); + cleared = true; + } + } + } +} + +static int psci_idle_syscore_suspend(void) +{ + psci_idle_syscore_switch(true); + return 0; +} + +static void psci_idle_syscore_resume(void) +{ + psci_idle_syscore_switch(false); +} + +static struct syscore_ops psci_idle_syscore_ops = { + .suspend = psci_idle_syscore_suspend, + .resume = psci_idle_syscore_resume, +}; + static void psci_idle_init_cpuhp(void) { int err; @@ -138,6 +182,8 @@ static void psci_idle_init_cpuhp(void) if (!psci_cpuidle_use_cpuhp) return; + register_syscore_ops(&psci_idle_syscore_ops); + err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING, "cpuidle/psci:online", psci_idle_cpuhp_up,
When PSCI OSI mode is supported the syscore flag is set for the CPU devices that becomes attached to their PM domains (genpds). In the suspend-to-idle case, we call dev_pm_genpd_suspend|resume() to allow genpd to properly manage the power-off/on operations (pick an idlestate and manage the on/off notifications). For suspend-to-ram, dev_pm_genpd_suspend|resume() is currently not being called, which causes a problem that the genpd on/off notifiers do not get sent as expected. This prevents the platform-specific operations from being executed, typically needed just before/after the boot CPU is being turned off/on. To deal with this problem, let's register a syscore ops for cpuidle-psci when PSCI OSI mode is being used and call dev_pm_genpd_suspend|resume() from them. In this way, genpd regains control of the PM domain topology and then sends the on/off notifications when it's appropriate. Reported-by: Maulik Shah <quic_mkshah@quicinc.com> Suggested-by: Maulik Shah <quic_mkshah@quicinc.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- drivers/cpuidle/cpuidle-psci.c | 46 ++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+)