Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

5 files changed, 43 insertions, 13 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 29b2fa5534a..44d1eca83a7 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -257,7 +257,7 @@ void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
 		if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
 			if ((policy) && (policy->cpu == freqs->cpu) &&
 			    (policy->cur) && (policy->cur != freqs->old)) {
-				dprintk(KERN_WARNING "Warning: CPU frequency is"
+				dprintk("Warning: CPU frequency is"
 					" %u, cpufreq assumed %u kHz.\n",
 					freqs->old, policy->cur);
 				freqs->old = policy->cur;
@@ -874,7 +874,7 @@ static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, unsigne
 {
 	struct cpufreq_freqs freqs;
 
-	dprintk(KERN_WARNING "Warning: CPU frequency out of sync: cpufreq and timing "
+	dprintk("Warning: CPU frequency out of sync: cpufreq and timing "
 	       "core thinks of %u, is %u kHz.\n", old_freq, new_freq);
 
 	freqs.cpu = cpu;
@@ -1006,7 +1006,7 @@ static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg)
 		struct cpufreq_freqs freqs;
 
 		if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN))
-			dprintk(KERN_DEBUG "Warning: CPU frequency is %u, "
+			dprintk("Warning: CPU frequency is %u, "
 			       "cpufreq assumed %u kHz.\n",
 			       cur_freq, cpu_policy->cur);
 
@@ -1087,7 +1087,7 @@ static int cpufreq_resume(struct sys_device * sysdev)
 			struct cpufreq_freqs freqs;
 
 			if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN))
-				dprintk(KERN_WARNING "Warning: CPU frequency"
+				dprintk("Warning: CPU frequency"
 				       "is %u, cpufreq assumed %u kHz.\n",
 				       cur_freq, cpu_policy->cur);
 
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index e07a35487bd..b3ebc8f0197 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -22,6 +22,7 @@
 #include <linux/types.h>
 #include <linux/fs.h>
 #include <linux/sysfs.h>
+#include <linux/cpu.h>
 #include <linux/sched.h>
 #include <linux/kmod.h>
 #include <linux/workqueue.h>
@@ -72,6 +73,14 @@ static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
 
 static unsigned int dbs_enable;	/* number of CPUs using this policy */
 
+/*
+ * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug
+ * lock and dbs_mutex. cpu_hotplug lock should always be held before
+ * dbs_mutex. If any function that can potentially take cpu_hotplug lock
+ * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, then
+ * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock
+ * is recursive for the same process. -Venki
+ */
 static DEFINE_MUTEX 	(dbs_mutex);
 static DECLARE_WORK	(dbs_work, do_dbs_timer, NULL);
 
@@ -414,12 +423,14 @@ static void dbs_check_cpu(int cpu)
 static void do_dbs_timer(void *data)
 { 
 	int i;
+	lock_cpu_hotplug();
 	mutex_lock(&dbs_mutex);
 	for_each_online_cpu(i)
 		dbs_check_cpu(i);
 	schedule_delayed_work(&dbs_work, 
 			usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
 	mutex_unlock(&dbs_mutex);
+	unlock_cpu_hotplug();
 } 
 
 static inline void dbs_timer_init(void)
@@ -514,6 +525,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 		break;
 
 	case CPUFREQ_GOV_LIMITS:
+		lock_cpu_hotplug();
 		mutex_lock(&dbs_mutex);
 		if (policy->max < this_dbs_info->cur_policy->cur)
 			__cpufreq_driver_target(
@@ -524,6 +536,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 					this_dbs_info->cur_policy,
 				       	policy->min, CPUFREQ_RELATION_L);
 		mutex_unlock(&dbs_mutex);
+		unlock_cpu_hotplug();
 		break;
 	}
 	return 0;
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 3e6ffcaa5af..693e540481b 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -21,6 +21,7 @@
 #include <linux/types.h>
 #include <linux/fs.h>
 #include <linux/sysfs.h>
+#include <linux/cpu.h>
 #include <linux/sched.h>
 #include <linux/kmod.h>
 #include <linux/workqueue.h>
@@ -71,6 +72,14 @@ static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
 
 static unsigned int dbs_enable;	/* number of CPUs using this policy */
 
+/*
+ * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug
+ * lock and dbs_mutex. cpu_hotplug lock should always be held before
+ * dbs_mutex. If any function that can potentially take cpu_hotplug lock
+ * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, then
+ * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock
+ * is recursive for the same process. -Venki
+ */
 static DEFINE_MUTEX (dbs_mutex);
 static DECLARE_WORK	(dbs_work, do_dbs_timer, NULL);
 
@@ -363,12 +372,14 @@ static void dbs_check_cpu(int cpu)
 static void do_dbs_timer(void *data)
 {
 	int i;
+	lock_cpu_hotplug();
 	mutex_lock(&dbs_mutex);
 	for_each_online_cpu(i)
 		dbs_check_cpu(i);
 	queue_delayed_work(dbs_workq, &dbs_work,
 			   usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
 	mutex_unlock(&dbs_mutex);
+	unlock_cpu_hotplug();
 }
 
 static inline void dbs_timer_init(void)
@@ -469,6 +480,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 		break;
 
 	case CPUFREQ_GOV_LIMITS:
+		lock_cpu_hotplug();
 		mutex_lock(&dbs_mutex);
 		if (policy->max < this_dbs_info->cur_policy->cur)
 			__cpufreq_driver_target(
@@ -479,6 +491,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 					this_dbs_info->cur_policy,
 					policy->min, CPUFREQ_RELATION_L);
 		mutex_unlock(&dbs_mutex);
+		unlock_cpu_hotplug();
 		break;
 	}
 	return 0;
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 9694b6ed326..c576c0b3f45 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -74,7 +74,7 @@ static ssize_t
 show_total_trans(struct cpufreq_policy *policy, char *buf)
 {
 	struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
-	if(!stat)
+	if (!stat)
 		return 0;
 	return sprintf(buf, "%d\n",
 			cpufreq_stats_table[stat->cpu]->total_trans);
@@ -86,7 +86,7 @@ show_time_in_state(struct cpufreq_policy *policy, char *buf)
 	ssize_t len = 0;
 	int i;
 	struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
-	if(!stat)
+	if (!stat)
 		return 0;
 	cpufreq_stats_update(stat->cpu);
 	for (i = 0; i < stat->state_num; i++) {
@@ -104,7 +104,7 @@ show_trans_table(struct cpufreq_policy *policy, char *buf)
 	int i, j;
 
 	struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
-	if(!stat)
+	if (!stat)
 		return 0;
 	cpufreq_stats_update(stat->cpu);
 	len += snprintf(buf + len, PAGE_SIZE - len, "   From  :    To\n");
diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c
index a4818ce8891..551f4ccf87f 100644
--- a/drivers/cpufreq/freq_table.c
+++ b/drivers/cpufreq/freq_table.c
@@ -20,7 +20,7 @@ int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 {
 	unsigned int min_freq = ~0;
 	unsigned int max_freq = 0;
-	unsigned int i = 0;
+	unsigned int i;
 
 	for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
 		unsigned int freq = table[i].frequency;
@@ -51,7 +51,7 @@ int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 				   struct cpufreq_frequency_table *table)
 {
 	unsigned int next_larger = ~0;
-	unsigned int i = 0;
+	unsigned int i;
 	unsigned int count = 0;
 
 	dprintk("request for verification of policy (%u - %u kHz) for cpu %u\n", policy->min, policy->max, policy->cpu);
@@ -91,20 +91,24 @@ int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 				   unsigned int relation,
 				   unsigned int *index)
 {
-	struct cpufreq_frequency_table optimal = { .index = ~0, };
-	struct cpufreq_frequency_table suboptimal = { .index = ~0, };
+	struct cpufreq_frequency_table optimal = {
+		.index = ~0,
+		.frequency = 0,
+	};
+	struct cpufreq_frequency_table suboptimal = {
+		.index = ~0,
+		.frequency = 0,
+	};
 	unsigned int i;
 
 	dprintk("request for target %u kHz (relation: %u) for cpu %u\n", target_freq, relation, policy->cpu);
 
 	switch (relation) {
 	case CPUFREQ_RELATION_H:
-		optimal.frequency = 0;
 		suboptimal.frequency = ~0;
 		break;
 	case CPUFREQ_RELATION_L:
 		optimal.frequency = ~0;
-		suboptimal.frequency = 0;
 		break;
 	}