Merge branch 'pm-cpufreq'

* pm-cpufreq:
  cpufreq: Make cpufreq_notify_transition & cpufreq_notify_post_transition static
  cpufreq: Convert existing drivers to use cpufreq_freq_transition_{begin|end}
  cpufreq: Make sure frequency transitions are serialized
  intel_pstate: Use del_timer_sync in intel_pstate_cpu_stop
  cpufreq: resume drivers before enabling governors

drivers/cpufreq/cpufreq-nforce2.c

@@ -270,7 +270,7 @@ static int nforce2_target(struct cpufreq_policy *policy,
 	pr_debug("Old CPU frequency %d kHz, new %d kHz\n",
 	       freqs.old, freqs.new);
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs);
 
 	/* Disable IRQs */
 	/* local_irq_save(flags); */
@@ -285,7 +285,7 @@ static int nforce2_target(struct cpufreq_policy *policy,
 	/* Enable IRQs */
 	/* local_irq_restore(flags); */
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+	cpufreq_freq_transition_end(policy, &freqs, 0);
 
 	return 0;
 }

drivers/cpufreq/cpufreq.c

@@ -331,16 +331,15 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
  * function. It is called twice on all CPU frequency changes that have
  * external effects.
  */
-void cpufreq_notify_transition(struct cpufreq_policy *policy,
+static void cpufreq_notify_transition(struct cpufreq_policy *policy,
 		struct cpufreq_freqs *freqs, unsigned int state)
 {
 	for_each_cpu(freqs->cpu, policy->cpus)
 		__cpufreq_notify_transition(policy, freqs, state);
 }
-EXPORT_SYMBOL_GPL(cpufreq_notify_transition);
 
 /* Do post notifications when there are chances that transition has failed */
-void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
+static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
 		struct cpufreq_freqs *freqs, int transition_failed)
 {
 	cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
@@ -351,7 +350,41 @@ void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
 	cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
 	cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
 }
-EXPORT_SYMBOL_GPL(cpufreq_notify_post_transition);
+
+void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
+		struct cpufreq_freqs *freqs)
+{
+wait:
+	wait_event(policy->transition_wait, !policy->transition_ongoing);
+
+	spin_lock(&policy->transition_lock);
+
+	if (unlikely(policy->transition_ongoing)) {
+		spin_unlock(&policy->transition_lock);
+		goto wait;
+	}
+
+	policy->transition_ongoing = true;
+
+	spin_unlock(&policy->transition_lock);
+
+	cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
+}
+EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
+
+void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
+		struct cpufreq_freqs *freqs, int transition_failed)
+{
+	if (unlikely(WARN_ON(!policy->transition_ongoing)))
+		return;
+
+	cpufreq_notify_post_transition(policy, freqs, transition_failed);
+
+	policy->transition_ongoing = false;
+
+	wake_up(&policy->transition_wait);
+}
+EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
 
 
 /*********************************************************************
@@ -985,6 +1018,8 @@ static struct cpufreq_policy *cpufreq_policy_alloc(void)
 
 	INIT_LIST_HEAD(&policy->policy_list);
 	init_rwsem(&policy->rwsem);
+	spin_lock_init(&policy->transition_lock);
+	init_waitqueue_head(&policy->transition_wait);
 
 	return policy;
 
@@ -1470,8 +1505,8 @@ static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq,
 	policy = per_cpu(cpufreq_cpu_data, cpu);
 	read_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs);
+	cpufreq_freq_transition_end(policy, &freqs, 0);
 }
 
 /**
@@ -1652,14 +1687,13 @@ void cpufreq_resume(void)
 	cpufreq_suspended = false;
 
 	list_for_each_entry(policy, &cpufreq_policy_list, policy_list) {
-		if (__cpufreq_governor(policy, CPUFREQ_GOV_START)
+		if (cpufreq_driver->resume && cpufreq_driver->resume(policy))
+			pr_err("%s: Failed to resume driver: %p\n", __func__,
+				policy);
+		else 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
@@ -1832,8 +1866,7 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 			pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
 				 __func__, policy->cpu, freqs.old, freqs.new);
 
-			cpufreq_notify_transition(policy, &freqs,
-					CPUFREQ_PRECHANGE);
+			cpufreq_freq_transition_begin(policy, &freqs);
 		}
 
 		retval = cpufreq_driver->target_index(policy, index);
@@ -1842,7 +1875,7 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 			       __func__, retval);
 
 		if (notify)
-			cpufreq_notify_post_transition(policy, &freqs, retval);
+			cpufreq_freq_transition_end(policy, &freqs, retval);
 	}
 
 out:

drivers/cpufreq/exynos5440-cpufreq.c

@@ -219,7 +219,7 @@ static int exynos_target(struct cpufreq_policy *policy, unsigned int index)
 	freqs.old = policy->cur;
 	freqs.new = freq_table[index].frequency;
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs);
 
 	/* Set the target frequency in all C0_3_PSTATE register */
 	for_each_cpu(i, policy->cpus) {
@@ -258,7 +258,7 @@ static void exynos_cpufreq_work(struct work_struct *work)
 		dev_crit(dvfs_info->dev, "New frequency out of range\n");
 		freqs.new = freqs.old;
 	}
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+	cpufreq_freq_transition_end(policy, &freqs, 0);
 
 	cpufreq_cpu_put(policy);
 	mutex_unlock(&cpufreq_lock);

drivers/cpufreq/gx-suspmod.c

@@ -265,7 +265,7 @@ static void gx_set_cpuspeed(struct cpufreq_policy *policy, unsigned int khz)
 
 	freqs.new = new_khz;
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs);
 	local_irq_save(flags);
 
 	if (new_khz != stock_freq) {
@@ -314,7 +314,7 @@ static void gx_set_cpuspeed(struct cpufreq_policy *policy, unsigned int khz)
 
 	gx_params->pci_suscfg = suscfg;
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+	cpufreq_freq_transition_end(policy, &freqs, 0);
 
 	pr_debug("suspend modulation w/ duration of ON:%d us, OFF:%d us\n",
 		gx_params->on_duration * 32, gx_params->off_duration * 32);

drivers/cpufreq/integrator-cpufreq.c

@@ -122,7 +122,7 @@ static int integrator_set_target(struct cpufreq_policy *policy,
 		return 0;
 	}
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs);
 
 	cm_osc = __raw_readl(cm_base + INTEGRATOR_HDR_OSC_OFFSET);
 
@@ -143,7 +143,7 @@ static int integrator_set_target(struct cpufreq_policy *policy,
 	 */
 	set_cpus_allowed(current, cpus_allowed);
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+	cpufreq_freq_transition_end(policy, &freqs, 0);
 
 	return 0;
 }

drivers/cpufreq/intel_pstate.c

@@ -778,7 +778,7 @@ static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
 
 	pr_info("intel_pstate CPU %d exiting\n", cpu_num);
 
-	del_timer(&all_cpu_data[cpu_num]->timer);
+	del_timer_sync(&all_cpu_data[cpu_num]->timer);
 	intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
 	kfree(all_cpu_data[cpu_num]);
 	all_cpu_data[cpu_num] = NULL;

drivers/cpufreq/longhaul.c

@@ -269,7 +269,7 @@ static void longhaul_setstate(struct cpufreq_policy *policy,
 	freqs.old = calc_speed(longhaul_get_cpu_mult());
 	freqs.new = speed;
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs);
 
 	pr_debug("Setting to FSB:%dMHz Mult:%d.%dx (%s)\n",
 			fsb, mult/10, mult%10, print_speed(speed/1000));
@@ -386,7 +386,7 @@ retry_loop:
 		}
 	}
 	/* Report true CPU frequency */
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+	cpufreq_freq_transition_end(policy, &freqs, 0);
 
 	if (!bm_timeout)
 		printk(KERN_INFO PFX "Warning: Timeout while waiting for "

drivers/cpufreq/pcc-cpufreq.c

@@ -215,7 +215,7 @@ static int pcc_cpufreq_target(struct cpufreq_policy *policy,
 
 	freqs.old = policy->cur;
 	freqs.new = target_freq;
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs);
 
 	input_buffer = 0x1 | (((target_freq * 100)
 			       / (ioread32(&pcch_hdr->nominal) * 1000)) << 8);
@@ -231,7 +231,7 @@ static int pcc_cpufreq_target(struct cpufreq_policy *policy,
 	status = ioread16(&pcch_hdr->status);
 	iowrite16(0, &pcch_hdr->status);
 
-	cpufreq_notify_post_transition(policy, &freqs, status != CMD_COMPLETE);
+	cpufreq_freq_transition_end(policy, &freqs, status != CMD_COMPLETE);
 	spin_unlock(&pcc_lock);
 
 	if (status != CMD_COMPLETE) {

drivers/cpufreq/powernow-k6.c

@@ -148,11 +148,11 @@ static int powernow_k6_target(struct cpufreq_policy *policy,
 	freqs.old = busfreq * powernow_k6_get_cpu_multiplier();
 	freqs.new = busfreq * clock_ratio[best_i].driver_data;
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs);
 
 	powernow_k6_set_cpu_multiplier(best_i);
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+	cpufreq_freq_transition_end(policy, &freqs, 0);
 
 	return 0;
 }

drivers/cpufreq/powernow-k7.c

@@ -269,7 +269,7 @@ static int powernow_target(struct cpufreq_policy *policy, unsigned int index)
 
 	freqs.new = powernow_table[index].frequency;
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs);
 
 	/* Now do the magic poking into the MSRs.  */
 
@@ -290,7 +290,7 @@ static int powernow_target(struct cpufreq_policy *policy, unsigned int index)
 	if (have_a0 == 1)
 		local_irq_enable();
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+	cpufreq_freq_transition_end(policy, &freqs, 0);
 
 	return 0;
 }

drivers/cpufreq/powernow-k8.c

@@ -963,9 +963,9 @@ static int transition_frequency_fidvid(struct powernow_k8_data *data,
 	policy = cpufreq_cpu_get(smp_processor_id());
 	cpufreq_cpu_put(policy);
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs);
 	res = transition_fid_vid(data, fid, vid);
-	cpufreq_notify_post_transition(policy, &freqs, res);
+	cpufreq_freq_transition_end(policy, &freqs, res);
 
 	return res;
 }

drivers/cpufreq/s3c24xx-cpufreq.c

@@ -217,7 +217,7 @@ static int s3c_cpufreq_settarget(struct cpufreq_policy *policy,
 	s3c_cpufreq_updateclk(clk_pclk, cpu_new.freq.pclk);
 
 	/* start the frequency change */
-	cpufreq_notify_transition(policy, &freqs.freqs, CPUFREQ_PRECHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs.freqs);
 
 	/* If hclk is staying the same, then we do not need to
 	 * re-write the IO or the refresh timings whilst we are changing
@@ -261,7 +261,7 @@ static int s3c_cpufreq_settarget(struct cpufreq_policy *policy,
 	local_irq_restore(flags);
 
 	/* notify everyone we've done this */
-	cpufreq_notify_transition(policy, &freqs.freqs, CPUFREQ_POSTCHANGE);
+	cpufreq_freq_transition_end(policy, &freqs.freqs, 0);
 
 	s3c_freq_dbg("%s: finished\n", __func__);
 	return 0;

drivers/cpufreq/sh-cpufreq.c

@@ -68,10 +68,10 @@ static int sh_cpufreq_target(struct cpufreq_policy *policy,
 	freqs.new	= (freq + 500) / 1000;
 	freqs.flags	= 0;
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs);
 	set_cpus_allowed_ptr(current, &cpus_allowed);
 	clk_set_rate(cpuclk, freq);
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+	cpufreq_freq_transition_end(policy, &freqs, 0);
 
 	dev_dbg(dev, "set frequency %lu Hz\n", freq);
 

drivers/cpufreq/unicore2-cpufreq.c

@@ -44,9 +44,9 @@ static int ucv2_target(struct cpufreq_policy *policy,
 	freqs.old = policy->cur;
 	freqs.new = target_freq;
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	cpufreq_freq_transition_begin(policy, &freqs);
 	ret = clk_set_rate(policy->mclk, target_freq * 1000);
-	cpufreq_notify_post_transition(policy, &freqs, ret);
+	cpufreq_freq_transition_end(policy, &freqs, ret);
 
 	return ret;
 }

include/linux/cpufreq.h

@@ -16,6 +16,7 @@
 #include <linux/completion.h>
 #include <linux/kobject.h>
 #include <linux/notifier.h>
+#include <linux/spinlock.h>
 #include <linux/sysfs.h>
 
 /*********************************************************************
@@ -104,6 +105,11 @@ struct cpufreq_policy {
 	 *     __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
 	 */
 	struct rw_semaphore	rwsem;
+
+	/* Synchronization for frequency transitions */
+	bool			transition_ongoing; /* Tracks transition status */
+	spinlock_t		transition_lock;
+	wait_queue_head_t	transition_wait;
 };
 
 /* Only for ACPI */
@@ -333,9 +339,9 @@ static inline void cpufreq_resume(void) {}
 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
 
-void cpufreq_notify_transition(struct cpufreq_policy *policy,
-		struct cpufreq_freqs *freqs, unsigned int state);
-void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
+void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
+		struct cpufreq_freqs *freqs);
+void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
 		struct cpufreq_freqs *freqs, int transition_failed);
 
 #else /* CONFIG_CPU_FREQ */