cpufreq: suspend governors on system suspend/hibernate

This patch adds cpufreq suspend/resume calls to dpm_{suspend|resume}_noirq()
for handling suspend/resume of cpufreq governors.

Lan Tianyu (Intel) & Jinhyuk Choi (Broadcom) found anr issue where
tunables configuration for clusters/sockets with non-boot CPUs was
getting lost after suspend/resume, as we were notifying governors
with CPUFREQ_GOV_POLICY_EXIT on removal of the last cpu for that
policy and so deallocating memory for tunables. This is fixed by
this patch as we don't allow any operation on governors after
device suspend and before device resume now.

Reported-and-tested-by: Lan Tianyu <tianyu.lan@intel.com>
Reported-by: Jinhyuk Choi <jinchoi@broadcom.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[rjw: Changelog, minor cleanups]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 9f098a82cf04b061edb203fff718ef0ca70e6328..10c3510d72a9426ad91dd4f76ec94db01239fa52 100644 (file)
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -29,6 +29,7 @@
 #include <linux/async.h>
 #include <linux/suspend.h>
 #include <trace/events/power.h>
+#include <linux/cpufreq.h>
 #include <linux/cpuidle.h>
 #include "../base.h"
 #include "power.h"
@@ -473,6 +474,7 @@ static void dpm_resume_noirq(pm_message_t state)
        dpm_show_time(starttime, state, "noirq");
        resume_device_irqs();
        cpuidle_resume();
+       cpufreq_resume();
 }
 
 /**
@@ -885,6 +887,7 @@ static int dpm_suspend_noirq(pm_message_t state)
        ktime_t starttime = ktime_get();
        int error = 0;
 
+       cpufreq_suspend();
        cpuidle_pause();
        suspend_device_irqs();
        mutex_lock(&dpm_list_mtx);

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 02d534da22dda0bb22277c4f80f7c1d27f24cd65..606224a8abc2db9bf7486c5382b7f7bc7c488c53 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -26,6 +26,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/suspend.h>
 #include <linux/syscore_ops.h>
 #include <linux/tick.h>
 #include <trace/events/power.h>
@@ -47,6 +48,9 @@ static LIST_HEAD(cpufreq_policy_list);
 static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor);
 #endif
 
+/* Flag to suspend/resume CPUFreq governors */
+static bool cpufreq_suspended;
+
 static inline bool has_target(void)
 {
        return cpufreq_driver->target_index || cpufreq_driver->target;
@@ -1462,6 +1466,41 @@ static struct subsys_interface cpufreq_interface = {
        .remove_dev     = cpufreq_remove_dev,
 };
 
+void cpufreq_suspend(void)
+{
+       struct cpufreq_policy *policy;
+
+       if (!has_target())
+               return;
+
+       pr_debug("%s: Suspending Governors\n", __func__);
+
+       list_for_each_entry(policy, &cpufreq_policy_list, policy_list)
+               if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP))
+                       pr_err("%s: Failed to stop governor for policy: %p\n",
+                               __func__, policy);
+
+       cpufreq_suspended = true;
+}
+
+void cpufreq_resume(void)
+{
+       struct cpufreq_policy *policy;
+
+       if (!has_target())
+               return;
+
+       pr_debug("%s: Resuming Governors\n", __func__);
+
+       cpufreq_suspended = false;
+
+       list_for_each_entry(policy, &cpufreq_policy_list, policy_list)
+               if (__cpufreq_governor(policy, CPUFREQ_GOV_START)
+                   || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))
+                       pr_err("%s: Failed to start governor for policy: %p\n",
+                               __func__, policy);
+}
+
 /**
  * cpufreq_bp_suspend - Prepare the boot CPU for system suspend.
  *
@@ -1764,6 +1803,10 @@ static int __cpufreq_governor(struct cpufreq_policy *policy,
        struct cpufreq_governor *gov = NULL;
 #endif
 
+       /* Don't start any governor operations if we are entering suspend */
+       if (cpufreq_suspended)
+               return 0;
+
        if (policy->governor->max_transition_latency &&
            policy->cpuinfo.transition_latency >
            policy->governor->max_transition_latency) {

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 5bd6ab9b0c2750fca49409c9714d41f1ce7a2d9f..91716658e9a19d8f3e09310c614498a540eb5f0c 100644 (file)
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -272,6 +272,14 @@ cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
                        policy->cpuinfo.max_freq);
 }
 
+#ifdef CONFIG_CPU_FREQ
+void cpufreq_suspend(void);
+void cpufreq_resume(void);
+#else
+static inline void cpufreq_suspend(void) {}
+static inline void cpufreq_resume(void) {}
+#endif
+
 /*********************************************************************
  *                     CPUFREQ NOTIFIER INTERFACE                    *
  *********************************************************************/