Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | [PATCH 2/2] PM: sleep: Pause cpuidle later and resume it earlier during system transitions | Date | Fri, 22 Oct 2021 18:07:47 +0200 |
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit 8651f97bd951 ("PM / cpuidle: System resume hang fix with cpuidle") that introduced cpuidle pausing during system suspend did that to work around a platform firmware issue causing systems to hang during resume if CPUs were allowed to enter idle states in the system suspend and resume code paths.
However, pausing cpuidle before the last phase of suspending devices is the source of an otherwise arbitrary difference between the suspend-to-idle path and other system suspend variants, so it is cleaner to do that later, before taking secondary CPUs offline (it is still safer to take secondary CPUs offline with cpuidle paused, though).
Modify the code accordingly, but in order to avoid code duplication, introduce new wrapper functions, pm_sleep_disable_secondary_cpus() and pm_sleep_enable_secondary_cpus(), to combine cpuidle_pause() and cpuidle_resume(), respectively, with the handling of secondary CPUs during system-wide transitions to sleep states.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> --- drivers/base/power/main.c | 8 +------- kernel/power/hibernate.c | 12 +++++++----- kernel/power/power.h | 14 ++++++++++++++ kernel/power/suspend.c | 10 ++-------- 4 files changed, 24 insertions(+), 20 deletions(-)
Index: linux-pm/kernel/power/suspend.c =================================================================== --- linux-pm.orig/kernel/power/suspend.c +++ linux-pm/kernel/power/suspend.c @@ -403,9 +403,6 @@ static int suspend_enter(suspend_state_t if (error) goto Devices_early_resume; - if (state != PM_SUSPEND_TO_IDLE) - cpuidle_pause(); - error = dpm_suspend_noirq(PMSG_SUSPEND); if (error) { pr_err("noirq suspend of devices failed\n"); @@ -423,7 +420,7 @@ static int suspend_enter(suspend_state_t goto Platform_wake; } - error = suspend_disable_secondary_cpus(); + error = pm_sleep_disable_secondary_cpus(); if (error || suspend_test(TEST_CPUS)) goto Enable_cpus; @@ -453,16 +450,13 @@ static int suspend_enter(suspend_state_t BUG_ON(irqs_disabled()); Enable_cpus: - suspend_enable_secondary_cpus(); + pm_sleep_enable_secondary_cpus(); Platform_wake: platform_resume_noirq(state); dpm_resume_noirq(PMSG_RESUME); Platform_early_resume: - if (state != PM_SUSPEND_TO_IDLE) - cpuidle_resume(); - platform_resume_early(state); Devices_early_resume: Index: linux-pm/kernel/power/hibernate.c =================================================================== --- linux-pm.orig/kernel/power/hibernate.c +++ linux-pm/kernel/power/hibernate.c @@ -300,7 +300,7 @@ static int create_image(int platform_mod if (error || hibernation_test(TEST_PLATFORM)) goto Platform_finish; - error = suspend_disable_secondary_cpus(); + error = pm_sleep_disable_secondary_cpus(); if (error || hibernation_test(TEST_CPUS)) goto Enable_cpus; @@ -342,7 +342,7 @@ static int create_image(int platform_mod local_irq_enable(); Enable_cpus: - suspend_enable_secondary_cpus(); + pm_sleep_enable_secondary_cpus(); /* Allow architectures to do nosmt-specific post-resume dances */ if (!in_suspend) @@ -466,6 +466,8 @@ static int resume_target_kernel(bool pla if (error) goto Cleanup; + cpuidle_pause(); + error = hibernate_resume_nonboot_cpu_disable(); if (error) goto Enable_cpus; @@ -509,7 +511,7 @@ static int resume_target_kernel(bool pla local_irq_enable(); Enable_cpus: - suspend_enable_secondary_cpus(); + pm_sleep_enable_secondary_cpus(); Cleanup: platform_restore_cleanup(platform_mode); @@ -587,7 +589,7 @@ int hibernation_platform_enter(void) if (error) goto Platform_finish; - error = suspend_disable_secondary_cpus(); + error = pm_sleep_disable_secondary_cpus(); if (error) goto Enable_cpus; @@ -609,7 +611,7 @@ int hibernation_platform_enter(void) local_irq_enable(); Enable_cpus: - suspend_enable_secondary_cpus(); + pm_sleep_enable_secondary_cpus(); Platform_finish: hibernation_ops->finish(); Index: linux-pm/drivers/base/power/main.c =================================================================== --- linux-pm.orig/drivers/base/power/main.c +++ linux-pm/drivers/base/power/main.c @@ -32,7 +32,6 @@ #include <linux/suspend.h> #include <trace/events/power.h> #include <linux/cpufreq.h> -#include <linux/cpuidle.h> #include <linux/devfreq.h> #include <linux/timer.h> @@ -879,7 +878,6 @@ void dpm_resume_early(pm_message_t state void dpm_resume_start(pm_message_t state) { dpm_resume_noirq(state); - cpuidle_resume(); dpm_resume_early(state); } EXPORT_SYMBOL_GPL(dpm_resume_start); @@ -1518,13 +1516,9 @@ int dpm_suspend_end(pm_message_t state) if (error) goto out; - cpuidle_pause(); - error = dpm_suspend_noirq(state); - if (error) { - cpuidle_resume(); + if (error) dpm_resume_early(resume_event(state)); - } out: dpm_show_time(starttime, state, error, "end"); Index: linux-pm/kernel/power/power.h =================================================================== --- linux-pm.orig/kernel/power/power.h +++ linux-pm/kernel/power/power.h @@ -4,6 +4,8 @@ #include <linux/utsname.h> #include <linux/freezer.h> #include <linux/compiler.h> +#include <linux/cpu.h> +#include <linux/cpuidle.h> struct swsusp_info { struct new_utsname uts; @@ -310,3 +312,15 @@ extern int pm_wake_lock(const char *buf) extern int pm_wake_unlock(const char *buf); #endif /* !CONFIG_PM_WAKELOCKS */ + +static inline int pm_sleep_disable_secondary_cpus(void) +{ + cpuidle_pause(); + return suspend_disable_secondary_cpus(); +} + +static inline void pm_sleep_enable_secondary_cpus(void) +{ + suspend_enable_secondary_cpus(); + cpuidle_resume(); +}
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