Merge branch 'v3.10/topic/cpufreq' of git://git.linaro.org/kernel/linux-linaro-stable into linux-linaro-lsk

drivers/base/power/main.c

@@ -28,6 +28,8 @@
 #include <linux/sched.h>
 #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"
@@ -713,6 +715,8 @@ void dpm_resume(pm_message_t state)
 	mutex_unlock(&dpm_list_mtx);
 	async_synchronize_full();
 	dpm_show_time(starttime, state, NULL);
+
+	cpufreq_resume();
 }
 
 /**
@@ -1177,6 +1181,8 @@ int dpm_suspend(pm_message_t state)
 
 	might_sleep();
 
+	cpufreq_suspend();
+
 	mutex_lock(&dpm_list_mtx);
 	pm_transition = state;
 	async_error = 0;

drivers/cpufreq/cpufreq.c

@@ -31,6 +31,8 @@
 #include <linux/completion.h>
 #include <linux/mutex.h>
 #include <linux/syscore_ops.h>
+#include <linux/suspend.h>
+#include <linux/tick.h>
 
 #include <trace/events/power.h>
 
@@ -48,6 +50,14 @@ static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor);
 static DEFINE_RWLOCK(cpufreq_driver_lock);
 static DEFINE_MUTEX(cpufreq_governor_lock);
 
+/* Flag to suspend/resume CPUFreq governors */
+static bool cpufreq_suspended;
+
+static inline bool has_target(void)
+{
+	return cpufreq_driver->target;
+}
+
 /*
  * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure
  * all cpufreq/hotplug/workqueue/etc related lock issues.
@@ -1275,83 +1285,90 @@ static struct subsys_interface cpufreq_interface = {
 
 
 /**
- * cpufreq_bp_suspend - Prepare the boot CPU for system suspend.
+ * cpufreq_suspend() - Suspend CPUFreq governors
  *
- * This function is only executed for the boot processor.  The other CPUs
- * have been put offline by means of CPU hotplug.
+ * Called during system wide Suspend/Hibernate cycles for suspending governors
+ * as some platforms can't change frequency after this point in suspend cycle.
+ * Because some of the devices (like: i2c, regulators, etc) they use for
+ * changing frequency are suspended quickly after this point.
  */
-static int cpufreq_bp_suspend(void)
+void cpufreq_suspend(void)
 {
-	int ret = 0;
+	struct cpufreq_policy *policy;
+	int cpu;
 
-	int cpu = smp_processor_id();
-	struct cpufreq_policy *cpu_policy;
+	if (!cpufreq_driver)
+		return;
 
-	pr_debug("suspending cpu %u\n", cpu);
+	if (!has_target())
+		return;
 
-	/* If there's no policy for the boot CPU, we have nothing to do. */
-	cpu_policy = cpufreq_cpu_get(cpu);
-	if (!cpu_policy)
-		return 0;
+	pr_debug("%s: Suspending Governors\n", __func__);
 
-	if (cpufreq_driver->suspend) {
-		ret = cpufreq_driver->suspend(cpu_policy);
-		if (ret)
-			printk(KERN_ERR "cpufreq: suspend failed in ->suspend "
-					"step on CPU %u\n", cpu_policy->cpu);
+	for_each_possible_cpu(cpu) {
+		if (!cpu_online(cpu))
+			continue;
+
+		policy = cpufreq_cpu_get(cpu);
+
+		if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP))
+			pr_err("%s: Failed to stop governor for policy: %p\n",
+				__func__, policy);
+		else if (cpufreq_driver->suspend
+		    && cpufreq_driver->suspend(policy))
+			pr_err("%s: Failed to suspend driver: %p\n", __func__,
+				policy);
 	}
 
-	cpufreq_cpu_put(cpu_policy);
-	return ret;
+	cpufreq_suspended = true;
 }
 
 /**
- * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU.
+ * cpufreq_resume() - Resume CPUFreq governors
  *
- *	1.) resume CPUfreq hardware support (cpufreq_driver->resume())
- *	2.) schedule call cpufreq_update_policy() ASAP as interrupts are
- *	    restored. It will verify that the current freq is in sync with
- *	    what we believe it to be. This is a bit later than when it
- *	    should be, but nonethteless it's better than calling
- *	    cpufreq_driver->get() here which might re-enable interrupts...
- *
- * This function is only executed for the boot CPU.  The other CPUs have not
- * been turned on yet.
+ * Called during system wide Suspend/Hibernate cycle for resuming governors that
+ * are suspended with cpufreq_suspend().
  */
-static void cpufreq_bp_resume(void)
+void cpufreq_resume(void)
 {
-	int ret = 0;
+	struct cpufreq_policy *policy;
+	int cpu;
 
-	int cpu = smp_processor_id();
-	struct cpufreq_policy *cpu_policy;
-
-	pr_debug("resuming cpu %u\n", cpu);
-
-	/* If there's no policy for the boot CPU, we have nothing to do. */
-	cpu_policy = cpufreq_cpu_get(cpu);
-	if (!cpu_policy)
+	if (!cpufreq_driver)
 		return;
 
-	if (cpufreq_driver->resume) {
-		ret = cpufreq_driver->resume(cpu_policy);
-		if (ret) {
-			printk(KERN_ERR "cpufreq: resume failed in ->resume "
-					"step on CPU %u\n", cpu_policy->cpu);
-			goto fail;
-		}
+	if (!has_target())
+		return;
+
+	pr_debug("%s: Resuming Governors\n", __func__);
+
+	cpufreq_suspended = false;
+
+	for_each_possible_cpu(cpu) {
+		if (!cpu_online(cpu))
+			continue;
+
+		policy = cpufreq_cpu_get(cpu);
+
+		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);
+		else if (cpufreq_driver->resume
+		    && cpufreq_driver->resume(policy))
+			pr_err("%s: Failed to resume driver: %p\n", __func__,
+				policy);
+
+		/*
+		 * schedule call cpufreq_update_policy() for boot CPU, i.e. last
+		 * policy in list. It will verify that the current freq is in
+		 * sync with what we believe it to be.
+		 */
+		if (cpu == 0)
+			schedule_work(&policy->update);
 	}
-
-	schedule_work(&cpu_policy->update);
-
-fail:
-	cpufreq_cpu_put(cpu_policy);
 }
 
-static struct syscore_ops cpufreq_syscore_ops = {
-	.suspend	= cpufreq_bp_suspend,
-	.resume		= cpufreq_bp_resume,
-};
-
 /**
  *	cpufreq_get_current_driver - return current driver's name
  *
@@ -1544,6 +1561,10 @@ 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) {
@@ -2001,7 +2022,6 @@ static int __init cpufreq_core_init(void)
 
 	cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
 	BUG_ON(!cpufreq_global_kobject);
-	register_syscore_ops(&cpufreq_syscore_ops);
 
 	return 0;
 }

include/linux/cpufreq.h

@@ -307,6 +307,18 @@ struct freq_attr {
 static struct freq_attr _name =			\
 __ATTR(_name, 0444, show_##_name, NULL)
 
+#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                    *
+ *********************************************************************/
+
 #define cpufreq_freq_attr_ro_perm(_name, _perm)	\
 static struct freq_attr _name =			\
 __ATTR(_name, _perm, show_##_name, NULL)