Merge branch 'next' (accumulated 3.16 merge window patches) into master

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

1 files changed, 47 insertions, 23 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index abda6609d3e..ae11dd51f81 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -354,6 +354,18 @@ static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
 		struct cpufreq_freqs *freqs)
 {
+
+	/*
+	 * Catch double invocations of _begin() which lead to self-deadlock.
+	 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
+	 * doesn't invoke _begin() on their behalf, and hence the chances of
+	 * double invocations are very low. Moreover, there are scenarios
+	 * where these checks can emit false-positive warnings in these
+	 * drivers; so we avoid that by skipping them altogether.
+	 */
+	WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
+				&& current == policy->transition_task);
+
 wait:
 	wait_event(policy->transition_wait, !policy->transition_ongoing);
 
@@ -365,6 +377,7 @@ wait:
 	}
 
 	policy->transition_ongoing = true;
+	policy->transition_task = current;
 
 	spin_unlock(&policy->transition_lock);
 
@@ -381,6 +394,7 @@ void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
 	cpufreq_notify_post_transition(policy, freqs, transition_failed);
 
 	policy->transition_ongoing = false;
+	policy->transition_task = NULL;
 
 	wake_up(&policy->transition_wait);
 }
@@ -1802,12 +1816,43 @@ EXPORT_SYMBOL(cpufreq_unregister_notifier);
  *                              GOVERNORS                            *
  *********************************************************************/
 
+static int __target_index(struct cpufreq_policy *policy,
+			  struct cpufreq_frequency_table *freq_table, int index)
+{
+	struct cpufreq_freqs freqs;
+	int retval = -EINVAL;
+	bool notify;
+
+	notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
+
+	if (notify) {
+		freqs.old = policy->cur;
+		freqs.new = freq_table[index].frequency;
+		freqs.flags = 0;
+
+		pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
+			 __func__, policy->cpu, freqs.old, freqs.new);
+
+		cpufreq_freq_transition_begin(policy, &freqs);
+	}
+
+	retval = cpufreq_driver->target_index(policy, index);
+	if (retval)
+		pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
+		       retval);
+
+	if (notify)
+		cpufreq_freq_transition_end(policy, &freqs, retval);
+
+	return retval;
+}
+
 int __cpufreq_driver_target(struct cpufreq_policy *policy,
 			    unsigned int target_freq,
 			    unsigned int relation)
 {
-	int retval = -EINVAL;
 	unsigned int old_target_freq = target_freq;
+	int retval = -EINVAL;
 
 	if (cpufreq_disabled())
 		return -ENODEV;
@@ -1834,8 +1879,6 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 		retval = cpufreq_driver->target(policy, target_freq, relation);
 	else if (cpufreq_driver->target_index) {
 		struct cpufreq_frequency_table *freq_table;
-		struct cpufreq_freqs freqs;
-		bool notify;
 		int index;
 
 		freq_table = cpufreq_frequency_get_table(policy->cpu);
@@ -1856,26 +1899,7 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 			goto out;
 		}
 
-		notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
-
-		if (notify) {
-			freqs.old = policy->cur;
-			freqs.new = freq_table[index].frequency;
-			freqs.flags = 0;
-
-			pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
-				 __func__, policy->cpu, freqs.old, freqs.new);
-
-			cpufreq_freq_transition_begin(policy, &freqs);
-		}
-
-		retval = cpufreq_driver->target_index(policy, index);
-		if (retval)
-			pr_err("%s: Failed to change cpu frequency: %d\n",
-			       __func__, retval);
-
-		if (notify)
-			cpufreq_freq_transition_end(policy, &freqs, retval);
+		retval = __target_index(policy, freq_table, index);
 	}
 
 out: