10 files changed, 362 insertions, 380 deletions

diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index a5b09e75e787..a1a6fd75cfe5 100644
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -541,7 +541,8 @@ static int snd_compress_check_input(struct snd_compr_params *params)
 {
 	/* first let's check the buffer parameter's */
 	if (params->buffer.fragment_size == 0 ||
-	    params->buffer.fragments > INT_MAX / params->buffer.fragment_size)
+	    params->buffer.fragments > INT_MAX / params->buffer.fragment_size ||
+	    params->buffer.fragments == 0)
 		return -EINVAL;
 
 	/* now codec parameters */
@@ -1014,22 +1015,13 @@ static int snd_compress_proc_init(struct snd_compr *compr)
 	if (!entry)
 		return -ENOMEM;
 	entry->mode = S_IFDIR | 0555;
-	if (snd_info_register(entry) < 0) {
-		snd_info_free_entry(entry);
-		return -ENOMEM;
-	}
 	compr->proc_root = entry;
 
 	entry = snd_info_create_card_entry(compr->card, "info",
 					   compr->proc_root);
-	if (entry) {
+	if (entry)
 		snd_info_set_text_ops(entry, compr,
 				      snd_compress_proc_info_read);
-		if (snd_info_register(entry) < 0) {
-			snd_info_free_entry(entry);
-			entry = NULL;
-		}
-	}
 	compr->proc_info_entry = entry;
 
 	return 0;
diff --git a/sound/core/info.c b/sound/core/info.c
index fe502bc5e6d2..96a074019c33 100644
--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -463,11 +463,12 @@ static struct snd_info_entry *create_subdir(struct module *mod,
 }
 
 static struct snd_info_entry *
-snd_info_create_entry(const char *name, struct snd_info_entry *parent);
+snd_info_create_entry(const char *name, struct snd_info_entry *parent,
+		      struct module *module);
 
 int __init snd_info_init(void)
 {
-	snd_proc_root = snd_info_create_entry("asound", NULL);
+	snd_proc_root = snd_info_create_entry("asound", NULL, THIS_MODULE);
 	if (!snd_proc_root)
 		return -ENOMEM;
 	snd_proc_root->mode = S_IFDIR | 0555;
@@ -503,6 +504,14 @@ int __exit snd_info_done(void)
 	return 0;
 }
 
+static void snd_card_id_read(struct snd_info_entry *entry,
+			     struct snd_info_buffer *buffer)
+{
+	struct snd_card *card = entry->private_data;
+
+	snd_iprintf(buffer, "%s\n", card->id);
+}
+
 /*
  * create a card proc file
  * called from init.c
@@ -520,28 +529,8 @@ int snd_info_card_create(struct snd_card *card)
 	if (!entry)
 		return -ENOMEM;
 	card->proc_root = entry;
-	return 0;
-}
-
-/* register all pending info entries */
-static int snd_info_register_recursive(struct snd_info_entry *entry)
-{
-	struct snd_info_entry *p;
-	int err;
 
-	if (!entry->p) {
-		err = snd_info_register(entry);
-		if (err < 0)
-			return err;
-	}
-
-	list_for_each_entry(p, &entry->children, list) {
-		err = snd_info_register_recursive(p);
-		if (err < 0)
-			return err;
-	}
-
-	return 0;
+	return snd_card_ro_proc_new(card, "id", card, snd_card_id_read);
 }
 
 /*
@@ -557,7 +546,7 @@ int snd_info_card_register(struct snd_card *card)
 	if (snd_BUG_ON(!card))
 		return -ENXIO;
 
-	err = snd_info_register_recursive(card->proc_root);
+	err = snd_info_register(card->proc_root);
 	if (err < 0)
 		return err;
 
@@ -705,7 +694,8 @@ EXPORT_SYMBOL(snd_info_get_str);
  * Return: The pointer of the new instance, or %NULL on failure.
  */
 static struct snd_info_entry *
-snd_info_create_entry(const char *name, struct snd_info_entry *parent)
+snd_info_create_entry(const char *name, struct snd_info_entry *parent,
+		      struct module *module)
 {
 	struct snd_info_entry *entry;
 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
@@ -722,6 +712,7 @@ snd_info_create_entry(const char *name, struct snd_info_entry *parent)
 	INIT_LIST_HEAD(&entry->children);
 	INIT_LIST_HEAD(&entry->list);
 	entry->parent = parent;
+	entry->module = module;
 	if (parent)
 		list_add_tail(&entry->list, &parent->children);
 	return entry;
@@ -741,10 +732,9 @@ struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 					       const char *name,
 					       struct snd_info_entry *parent)
 {
-	struct snd_info_entry *entry = snd_info_create_entry(name, parent);
-	if (entry)
-		entry->module = module;
-	return entry;
+	if (!parent)
+		parent = snd_proc_root;
+	return snd_info_create_entry(name, parent, module);
 }
 EXPORT_SYMBOL(snd_info_create_module_entry);
 
@@ -762,12 +752,9 @@ struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 					     const char *name,
 					     struct snd_info_entry * parent)
 {
-	struct snd_info_entry *entry = snd_info_create_entry(name, parent);
-	if (entry) {
-		entry->module = card->module;
-		entry->card = card;
-	}
-	return entry;
+	if (!parent)
+		parent = card->proc_root;
+	return snd_info_create_entry(name, parent, card->module);
 }
 EXPORT_SYMBOL(snd_info_create_card_entry);
 
@@ -813,15 +800,7 @@ void snd_info_free_entry(struct snd_info_entry * entry)
 }
 EXPORT_SYMBOL(snd_info_free_entry);
 
-/**
- * snd_info_register - register the info entry
- * @entry: the info entry
- *
- * Registers the proc info entry.
- *
- * Return: Zero if successful, or a negative error code on failure.
- */
-int snd_info_register(struct snd_info_entry * entry)
+static int __snd_info_register(struct snd_info_entry *entry)
 {
 	struct proc_dir_entry *root, *p = NULL;
 
@@ -829,6 +808,8 @@ int snd_info_register(struct snd_info_entry * entry)
 		return -ENXIO;
 	root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p;
 	mutex_lock(&info_mutex);
+	if (entry->p || !root)
+		goto unlock;
 	if (S_ISDIR(entry->mode)) {
 		p = proc_mkdir_mode(entry->name, entry->mode, root);
 		if (!p) {
@@ -850,11 +831,73 @@ int snd_info_register(struct snd_info_entry * entry)
 		proc_set_size(p, entry->size);
 	}
 	entry->p = p;
+ unlock:
 	mutex_unlock(&info_mutex);
 	return 0;
 }
+
+/**
+ * snd_info_register - register the info entry
+ * @entry: the info entry
+ *
+ * Registers the proc info entry.
+ * The all children entries are registered recursively.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_info_register(struct snd_info_entry *entry)
+{
+	struct snd_info_entry *p;
+	int err;
+
+	if (!entry->p) {
+		err = __snd_info_register(entry);
+		if (err < 0)
+			return err;
+	}
+
+	list_for_each_entry(p, &entry->children, list) {
+		err = snd_info_register(p);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
 EXPORT_SYMBOL(snd_info_register);
 
+/**
+ * snd_card_rw_proc_new - Create a read/write text proc file entry for the card
+ * @card: the card instance
+ * @name: the file name
+ * @private_data: the arbitrary private data
+ * @read: the read callback
+ * @write: the write callback, NULL for read-only
+ *
+ * This proc file entry will be registered via snd_card_register() call, and
+ * it will be removed automatically at the card removal, too.
+ */
+int snd_card_rw_proc_new(struct snd_card *card, const char *name,
+			 void *private_data,
+			 void (*read)(struct snd_info_entry *,
+				      struct snd_info_buffer *),
+			 void (*write)(struct snd_info_entry *entry,
+				       struct snd_info_buffer *buffer))
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_card_entry(card, name, card->proc_root);
+	if (!entry)
+		return -ENOMEM;
+	snd_info_set_text_ops(entry, private_data, read);
+	if (write) {
+		entry->mode |= 0200;
+		entry->c.text.write = write;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_card_rw_proc_new);
+
 /*
 
  */
diff --git a/sound/core/init.c b/sound/core/init.c
index 4849c611c0fe..0c4dc40376a7 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -100,31 +100,6 @@ int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
 #endif
 
-#ifdef CONFIG_SND_PROC_FS
-static void snd_card_id_read(struct snd_info_entry *entry,
-			     struct snd_info_buffer *buffer)
-{
-	snd_iprintf(buffer, "%s\n", entry->card->id);
-}
-
-static int init_info_for_card(struct snd_card *card)
-{
-	struct snd_info_entry *entry;
-
-	entry = snd_info_create_card_entry(card, "id", card->proc_root);
-	if (!entry) {
-		dev_dbg(card->dev, "unable to create card entry\n");
-		return -ENOMEM;
-	}
-	entry->c.text.read = snd_card_id_read;
-	card->proc_id = entry;
-
-	return snd_info_card_register(card);
-}
-#else /* !CONFIG_SND_PROC_FS */
-#define init_info_for_card(card)
-#endif
-
 static int check_empty_slot(struct module *module, int slot)
 {
 	return !slots[slot] || !*slots[slot];
@@ -491,7 +466,6 @@ static int snd_card_do_free(struct snd_card *card)
 	snd_device_free_all(card);
 	if (card->private_free)
 		card->private_free(card);
-	snd_info_free_entry(card->proc_id);
 	if (snd_info_card_free(card) < 0) {
 		dev_warn(card->dev, "unable to free card info\n");
 		/* Not fatal error */
@@ -795,7 +769,10 @@ int snd_card_register(struct snd_card *card)
 	}
 	snd_cards[card->number] = card;
 	mutex_unlock(&snd_card_mutex);
-	init_info_for_card(card);
+	err = snd_info_card_register(card);
+	if (err < 0)
+		return err;
+
 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
 	if (snd_mixer_oss_notify_callback)
 		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index 59a4adc286ed..eb974235c92b 100644
--- a/sound/core/memalloc.c
+++ b/sound/core/memalloc.c
@@ -182,6 +182,8 @@ int snd_dma_alloc_pages(int type, struct device *device, size_t size,
 		return -ENXIO;
 	if (WARN_ON(!dmab))
 		return -ENXIO;
+	if (WARN_ON(!device))
+		return -EINVAL;
 
 	dmab->dev.type = type;
 	dmab->dev.dev = device;
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index 467039b342b5..d5b0d7ba83c4 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -2427,7 +2427,6 @@ static int snd_pcm_oss_open_file(struct file *file,
 		}
 
 		pcm_oss_file->streams[idx] = substream;
-		substream->file = pcm_oss_file;
 		snd_pcm_oss_init_substream(substream, &setup[idx], minor);
 	}
 	
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 01b9d62eef14..7b63aee124af 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -528,52 +528,44 @@ static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
 	if (!entry)
 		return -ENOMEM;
 	entry->mode = S_IFDIR | 0555;
-	if (snd_info_register(entry) < 0) {
-		snd_info_free_entry(entry);
-		return -ENOMEM;
-	}
 	pstr->proc_root = entry;
 	entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
-	if (entry) {
+	if (entry)
 		snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
-		if (snd_info_register(entry) < 0) {
-			snd_info_free_entry(entry);
-			entry = NULL;
-		}
-	}
-	pstr->proc_info_entry = entry;
-
 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 	entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
 					   pstr->proc_root);
 	if (entry) {
-		entry->c.text.read = snd_pcm_xrun_debug_read;
+		snd_info_set_text_ops(entry, pstr, snd_pcm_xrun_debug_read);
 		entry->c.text.write = snd_pcm_xrun_debug_write;
 		entry->mode |= 0200;
-		entry->private_data = pstr;
-		if (snd_info_register(entry) < 0) {
-			snd_info_free_entry(entry);
-			entry = NULL;
-		}
 	}
-	pstr->proc_xrun_debug_entry = entry;
 #endif
 	return 0;
 }
 
 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
 {
-#ifdef CONFIG_SND_PCM_XRUN_DEBUG
-	snd_info_free_entry(pstr->proc_xrun_debug_entry);
-	pstr->proc_xrun_debug_entry = NULL;
-#endif
-	snd_info_free_entry(pstr->proc_info_entry);
-	pstr->proc_info_entry = NULL;
 	snd_info_free_entry(pstr->proc_root);
 	pstr->proc_root = NULL;
 	return 0;
 }
 
+static struct snd_info_entry *
+create_substream_info_entry(struct snd_pcm_substream *substream,
+			    const char *name,
+			    void (*read)(struct snd_info_entry *,
+					 struct snd_info_buffer *))
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_card_entry(substream->pcm->card, name,
+					   substream->proc_root);
+	if (entry)
+		snd_info_set_text_ops(entry, substream, read);
+	return entry;
+}
+
 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 {
 	struct snd_info_entry *entry;
@@ -588,101 +580,61 @@ static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 	if (!entry)
 		return -ENOMEM;
 	entry->mode = S_IFDIR | 0555;
-	if (snd_info_register(entry) < 0) {
-		snd_info_free_entry(entry);
-		return -ENOMEM;
-	}
 	substream->proc_root = entry;
-	entry = snd_info_create_card_entry(card, "info", substream->proc_root);
-	if (entry) {
-		snd_info_set_text_ops(entry, substream,
-				      snd_pcm_substream_proc_info_read);
-		if (snd_info_register(entry) < 0) {
-			snd_info_free_entry(entry);
-			entry = NULL;
-		}
-	}
-	substream->proc_info_entry = entry;
-	entry = snd_info_create_card_entry(card, "hw_params",
-					   substream->proc_root);
-	if (entry) {
-		snd_info_set_text_ops(entry, substream,
-				      snd_pcm_substream_proc_hw_params_read);
-		if (snd_info_register(entry) < 0) {
-			snd_info_free_entry(entry);
-			entry = NULL;
-		}
-	}
-	substream->proc_hw_params_entry = entry;
-	entry = snd_info_create_card_entry(card, "sw_params",
-					   substream->proc_root);
-	if (entry) {
-		snd_info_set_text_ops(entry, substream,
-				      snd_pcm_substream_proc_sw_params_read);
-		if (snd_info_register(entry) < 0) {
-			snd_info_free_entry(entry);
-			entry = NULL;
-		}
-	}
-	substream->proc_sw_params_entry = entry;
-	entry = snd_info_create_card_entry(card, "status",
-					   substream->proc_root);
-	if (entry) {
-		snd_info_set_text_ops(entry, substream,
-				      snd_pcm_substream_proc_status_read);
-		if (snd_info_register(entry) < 0) {
-			snd_info_free_entry(entry);
-			entry = NULL;
-		}
-	}
-	substream->proc_status_entry = entry;
+
+	create_substream_info_entry(substream, "info",
+				    snd_pcm_substream_proc_info_read);
+	create_substream_info_entry(substream, "hw_params",
+				    snd_pcm_substream_proc_hw_params_read);
+	create_substream_info_entry(substream, "sw_params",
+				    snd_pcm_substream_proc_sw_params_read);
+	create_substream_info_entry(substream, "status",
+				    snd_pcm_substream_proc_status_read);
 
 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
-	entry = snd_info_create_card_entry(card, "xrun_injection",
-					   substream->proc_root);
+	entry = create_substream_info_entry(substream, "xrun_injection", NULL);
 	if (entry) {
-		entry->private_data = substream;
-		entry->c.text.read = NULL;
 		entry->c.text.write = snd_pcm_xrun_injection_write;
 		entry->mode = S_IFREG | 0200;
-		if (snd_info_register(entry) < 0) {
-			snd_info_free_entry(entry);
-			entry = NULL;
-		}
 	}
-	substream->proc_xrun_injection_entry = entry;
 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
 
 	return 0;
 }
 
-static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
-{
-	snd_info_free_entry(substream->proc_info_entry);
-	substream->proc_info_entry = NULL;
-	snd_info_free_entry(substream->proc_hw_params_entry);
-	substream->proc_hw_params_entry = NULL;
-	snd_info_free_entry(substream->proc_sw_params_entry);
-	substream->proc_sw_params_entry = NULL;
-	snd_info_free_entry(substream->proc_status_entry);
-	substream->proc_status_entry = NULL;
-#ifdef CONFIG_SND_PCM_XRUN_DEBUG
-	snd_info_free_entry(substream->proc_xrun_injection_entry);
-	substream->proc_xrun_injection_entry = NULL;
-#endif
-	snd_info_free_entry(substream->proc_root);
-	substream->proc_root = NULL;
-	return 0;
-}
 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
-static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 
 static const struct attribute_group *pcm_dev_attr_groups[];
 
+/*
+ * PM callbacks: we need to deal only with suspend here, as the resume is
+ * triggered either from user-space or the driver's resume callback
+ */
+#ifdef CONFIG_PM_SLEEP
+static int do_pcm_suspend(struct device *dev)
+{
+	struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
+
+	if (!pstr->pcm->no_device_suspend)
+		snd_pcm_suspend_all(pstr->pcm);
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops pcm_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
+};
+
+/* device type for PCM -- basically only for passing PM callbacks */
+static const struct device_type pcm_dev_type = {
+	.name = "pcm",
+	.pm = &pcm_dev_pm_ops,
+};
+
 /**
  * snd_pcm_new_stream - create a new PCM stream
  * @pcm: the pcm instance
@@ -713,6 +665,7 @@ int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 
 	snd_device_initialize(&pstr->dev, pcm->card);
 	pstr->dev.groups = pcm_dev_attr_groups;
+	pstr->dev.type = &pcm_dev_type;
 	dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
 		     stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 
@@ -753,9 +706,7 @@ int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 			}
 		}
 		substream->group = &substream->self_group;
-		spin_lock_init(&substream->self_group.lock);
-		mutex_init(&substream->self_group.mutex);
-		INIT_LIST_HEAD(&substream->self_group.substreams);
+		snd_pcm_group_init(&substream->self_group);
 		list_add_tail(&substream->link_list, &substream->self_group.substreams);
 		atomic_set(&substream->mmap_count, 0);
 		prev = substream;
@@ -885,15 +836,17 @@ static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 	struct snd_pcm_oss_setup *setup, *setupn;
 #endif
+
+	/* free all proc files under the stream */
+	snd_pcm_stream_proc_done(pstr);
+
 	substream = pstr->substream;
 	while (substream) {
 		substream_next = substream->next;
 		snd_pcm_timer_done(substream);
-		snd_pcm_substream_proc_done(substream);
 		kfree(substream);
 		substream = substream_next;
 	}
-	snd_pcm_stream_proc_done(pstr);
 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
 		setupn = setup->next;
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 40013b26f671..345ab1ab2cac 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -2176,17 +2176,16 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
 		snd_pcm_update_hw_ptr(substream);
 
+	/*
+	 * If size < start_threshold, wait indefinitely. Another
+	 * thread may start capture
+	 */
 	if (!is_playback &&
-	    runtime->status->state == SNDRV_PCM_STATE_PREPARED) {
-		if (size >= runtime->start_threshold) {
-			err = snd_pcm_start(substream);
-			if (err < 0)
-				goto _end_unlock;
-		} else {
-			/* nothing to do */
-			err = 0;
+	    runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
+	    size >= runtime->start_threshold) {
+		err = snd_pcm_start(substream);
+		if (err < 0)
 			goto _end_unlock;
-		}
 	}
 
 	avail = snd_pcm_avail(substream);
@@ -2219,9 +2218,8 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
 		if (frames > cont)
 			frames = cont;
 		if (snd_BUG_ON(!frames)) {
-			runtime->twake = 0;
-			snd_pcm_stream_unlock_irq(substream);
-			return -EINVAL;
+			err = -EINVAL;
+			goto _end_unlock;
 		}
 		snd_pcm_stream_unlock_irq(substream);
 		err = writer(substream, appl_ofs, data, offset, frames,
diff --git a/sound/core/pcm_local.h b/sound/core/pcm_local.h
index c515612969a4..0b4b5dfaec18 100644
--- a/sound/core/pcm_local.h
+++ b/sound/core/pcm_local.h
@@ -66,5 +66,6 @@ static inline void snd_pcm_timer_done(struct snd_pcm_substream *substream) {}
 #endif
 
 void __snd_pcm_xrun(struct snd_pcm_substream *substream);
+void snd_pcm_group_init(struct snd_pcm_group *group);
 
 #endif	/* __SOUND_CORE_PCM_LOCAL_H */
diff --git a/sound/core/pcm_memory.c b/sound/core/pcm_memory.c
index 4b5356a10315..ed73be80bd29 100644
--- a/sound/core/pcm_memory.c
+++ b/sound/core/pcm_memory.c
@@ -87,19 +87,10 @@ static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream
  * @substream: the pcm substream instance
  *
  * Releases the pre-allocated buffer of the given substream.
- *
- * Return: Zero if successful, or a negative error code on failure.
  */
-int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
+void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
 {
 	snd_pcm_lib_preallocate_dma_free(substream);
-#ifdef CONFIG_SND_VERBOSE_PROCFS
-	snd_info_free_entry(substream->proc_prealloc_max_entry);
-	substream->proc_prealloc_max_entry = NULL;
-	snd_info_free_entry(substream->proc_prealloc_entry);
-	substream->proc_prealloc_entry = NULL;
-#endif
-	return 0;
 }
 
 /**
@@ -107,10 +98,8 @@ int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
  * @pcm: the pcm instance
  *
  * Releases all the pre-allocated buffers on the given pcm.
- *
- * Return: Zero if successful, or a negative error code on failure.
  */
-int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
+void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
 {
 	struct snd_pcm_substream *substream;
 	int stream;
@@ -118,7 +107,6 @@ int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
 	for (stream = 0; stream < 2; stream++)
 		for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
 			snd_pcm_lib_preallocate_free(substream);
-	return 0;
 }
 EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
 
@@ -198,26 +186,19 @@ static inline void preallocate_info_init(struct snd_pcm_substream *substream)
 {
 	struct snd_info_entry *entry;
 
-	if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
-		entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
+	entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
+					   substream->proc_root);
+	if (entry) {
+		snd_info_set_text_ops(entry, substream,
+				      snd_pcm_lib_preallocate_proc_read);
 		entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
 		entry->mode |= 0200;
-		entry->private_data = substream;
-		if (snd_info_register(entry) < 0) {
-			snd_info_free_entry(entry);
-			entry = NULL;
-		}
 	}
-	substream->proc_prealloc_entry = entry;
-	if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
-		entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
-		entry->private_data = substream;
-		if (snd_info_register(entry) < 0) {
-			snd_info_free_entry(entry);
-			entry = NULL;
-		}
-	}
-	substream->proc_prealloc_max_entry = entry;
+	entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
+					   substream->proc_root);
+	if (entry)
+		snd_info_set_text_ops(entry, substream,
+				      snd_pcm_lib_preallocate_max_proc_read);
 }
 
 #else /* !CONFIG_SND_VERBOSE_PROCFS */
@@ -227,7 +208,7 @@ static inline void preallocate_info_init(struct snd_pcm_substream *substream)
 /*
  * pre-allocate the buffer and create a proc file for the substream
  */
-static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
+static void snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
 					  size_t size, size_t max)
 {
 
@@ -238,7 +219,6 @@ static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
 		substream->buffer_bytes_max = substream->dma_buffer.bytes;
 	substream->dma_max = max;
 	preallocate_info_init(substream);
-	return 0;
 }
 
 
@@ -251,16 +231,14 @@ static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
  * @max: the max. allowed pre-allocation size
  *
  * Do pre-allocation for the given DMA buffer type.
- *
- * Return: Zero if successful, or a negative error code on failure.
  */
-int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
+void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
 				  int type, struct device *data,
 				  size_t size, size_t max)
 {
 	substream->dma_buffer.dev.type = type;
 	substream->dma_buffer.dev.dev = data;
-	return snd_pcm_lib_preallocate_pages1(substream, size, max);
+	snd_pcm_lib_preallocate_pages1(substream, size, max);
 }
 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
 
@@ -274,21 +252,17 @@ EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
  *
  * Do pre-allocation to all substreams of the given pcm for the
  * specified DMA type.
- *
- * Return: Zero if successful, or a negative error code on failure.
  */
-int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
+void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
 					  int type, void *data,
 					  size_t size, size_t max)
 {
 	struct snd_pcm_substream *substream;
-	int stream, err;
+	int stream;
 
 	for (stream = 0; stream < 2; stream++)
 		for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
-			if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
-				return err;
-	return 0;
+			snd_pcm_lib_preallocate_pages(substream, type, data, size, max);
 }
 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
 
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 818dff1de545..f731f904e8cc 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -85,71 +85,30 @@ static int snd_pcm_open(struct file *file, struct snd_pcm *pcm, int stream);
  *
  */
 
-static DEFINE_RWLOCK(snd_pcm_link_rwlock);
 static DECLARE_RWSEM(snd_pcm_link_rwsem);
 
-/* Writer in rwsem may block readers even during its waiting in queue,
- * and this may lead to a deadlock when the code path takes read sem
- * twice (e.g. one in snd_pcm_action_nonatomic() and another in
- * snd_pcm_stream_lock()).  As a (suboptimal) workaround, let writer to
- * sleep until all the readers are completed without blocking by writer.
- */
-static inline void down_write_nonfifo(struct rw_semaphore *lock)
+void snd_pcm_group_init(struct snd_pcm_group *group)
 {
-	while (!down_write_trylock(lock))
-		msleep(1);
+	spin_lock_init(&group->lock);
+	mutex_init(&group->mutex);
+	INIT_LIST_HEAD(&group->substreams);
+	refcount_set(&group->refs, 0);
 }
 
-#define PCM_LOCK_DEFAULT	0
-#define PCM_LOCK_IRQ	1
-#define PCM_LOCK_IRQSAVE	2
-
-static unsigned long __snd_pcm_stream_lock_mode(struct snd_pcm_substream *substream,
-						unsigned int mode)
-{
-	unsigned long flags = 0;
-	if (substream->pcm->nonatomic) {
-		down_read_nested(&snd_pcm_link_rwsem, SINGLE_DEPTH_NESTING);
-		mutex_lock(&substream->self_group.mutex);
-	} else {
-		switch (mode) {
-		case PCM_LOCK_DEFAULT:
-			read_lock(&snd_pcm_link_rwlock);
-			break;
-		case PCM_LOCK_IRQ:
-			read_lock_irq(&snd_pcm_link_rwlock);
-			break;
-		case PCM_LOCK_IRQSAVE:
-			read_lock_irqsave(&snd_pcm_link_rwlock, flags);
-			break;
-		}
-		spin_lock(&substream->self_group.lock);
-	}
-	return flags;
+/* define group lock helpers */
+#define DEFINE_PCM_GROUP_LOCK(action, mutex_action) \
+static void snd_pcm_group_ ## action(struct snd_pcm_group *group, bool nonatomic) \
+{ \
+	if (nonatomic) \
+		mutex_ ## mutex_action(&group->mutex); \
+	else \
+		spin_ ## action(&group->lock); \
 }
 
-static void __snd_pcm_stream_unlock_mode(struct snd_pcm_substream *substream,
-					 unsigned int mode, unsigned long flags)
-{
-	if (substream->pcm->nonatomic) {
-		mutex_unlock(&substream->self_group.mutex);
-		up_read(&snd_pcm_link_rwsem);
-	} else {
-		spin_unlock(&substream->self_group.lock);
-
-		switch (mode) {
-		case PCM_LOCK_DEFAULT:
-			read_unlock(&snd_pcm_link_rwlock);
-			break;
-		case PCM_LOCK_IRQ:
-			read_unlock_irq(&snd_pcm_link_rwlock);
-			break;
-		case PCM_LOCK_IRQSAVE:
-			read_unlock_irqrestore(&snd_pcm_link_rwlock, flags);
-			break;
-		}
-	}
-}
+DEFINE_PCM_GROUP_LOCK(lock, lock);
+DEFINE_PCM_GROUP_LOCK(unlock, unlock);
+DEFINE_PCM_GROUP_LOCK(lock_irq, lock);
+DEFINE_PCM_GROUP_LOCK(unlock_irq, unlock);
 
 /**
  * snd_pcm_stream_lock - Lock the PCM stream
@@ -161,7 +120,7 @@ static void __snd_pcm_stream_unlock_mode(struct snd_pcm_substream *substream,
  */
 void snd_pcm_stream_lock(struct snd_pcm_substream *substream)
 {
-	__snd_pcm_stream_lock_mode(substream, PCM_LOCK_DEFAULT);
+	snd_pcm_group_lock(&substream->self_group, substream->pcm->nonatomic);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_lock);
 
@@ -173,7 +132,7 @@ EXPORT_SYMBOL_GPL(snd_pcm_stream_lock);
  */
 void snd_pcm_stream_unlock(struct snd_pcm_substream *substream)
 {
-	__snd_pcm_stream_unlock_mode(substream, PCM_LOCK_DEFAULT, 0);
+	snd_pcm_group_unlock(&substream->self_group, substream->pcm->nonatomic);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock);
 
@@ -187,7 +146,8 @@ EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock);
  */
 void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream)
 {
-	__snd_pcm_stream_lock_mode(substream, PCM_LOCK_IRQ);
+	snd_pcm_group_lock_irq(&substream->self_group,
+			       substream->pcm->nonatomic);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_lock_irq);
 
@@ -199,13 +159,19 @@ EXPORT_SYMBOL_GPL(snd_pcm_stream_lock_irq);
  */
 void snd_pcm_stream_unlock_irq(struct snd_pcm_substream *substream)
 {
-	__snd_pcm_stream_unlock_mode(substream, PCM_LOCK_IRQ, 0);
+	snd_pcm_group_unlock_irq(&substream->self_group,
+				 substream->pcm->nonatomic);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irq);
 
 unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream)
 {
-	return __snd_pcm_stream_lock_mode(substream, PCM_LOCK_IRQSAVE);
+	unsigned long flags = 0;
+	if (substream->pcm->nonatomic)
+		mutex_lock(&substream->self_group.mutex);
+	else
+		spin_lock_irqsave(&substream->self_group.lock, flags);
+	return flags;
 }
 EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave);
 
@@ -219,7 +185,10 @@ EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave);
 void snd_pcm_stream_unlock_irqrestore(struct snd_pcm_substream *substream,
 				      unsigned long flags)
 {
-	__snd_pcm_stream_unlock_mode(substream, PCM_LOCK_IRQSAVE, flags);
+	if (substream->pcm->nonatomic)
+		mutex_unlock(&substream->self_group.mutex);
+	else
+		spin_unlock_irqrestore(&substream->self_group.lock, flags);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irqrestore);
 
@@ -1124,6 +1093,68 @@ static int snd_pcm_action_single(const struct action_ops *ops,
 	return res;
 }
 
+static void snd_pcm_group_assign(struct snd_pcm_substream *substream,
+				 struct snd_pcm_group *new_group)
+{
+	substream->group = new_group;
+	list_move(&substream->link_list, &new_group->substreams);
+}
+
+/*
+ * Unref and unlock the group, but keep the stream lock;
+ * when the group becomes empty and no longer referred, destroy itself
+ */
+static void snd_pcm_group_unref(struct snd_pcm_group *group,
+				struct snd_pcm_substream *substream)
+{
+	bool do_free;
+
+	if (!group)
+		return;
+	do_free = refcount_dec_and_test(&group->refs) &&
+		list_empty(&group->substreams);
+	snd_pcm_group_unlock(group, substream->pcm->nonatomic);
+	if (do_free)
+		kfree(group);
+}
+
+/*
+ * Lock the group inside a stream lock and reference it;
+ * return the locked group object, or NULL if not linked
+ */
+static struct snd_pcm_group *
+snd_pcm_stream_group_ref(struct snd_pcm_substream *substream)
+{
+	bool nonatomic = substream->pcm->nonatomic;
+	struct snd_pcm_group *group;
+	bool trylock;
+
+	for (;;) {
+		if (!snd_pcm_stream_linked(substream))
+			return NULL;
+		group = substream->group;
+		/* block freeing the group object */
+		refcount_inc(&group->refs);
+
+		trylock = nonatomic ? mutex_trylock(&group->mutex) :
+			spin_trylock(&group->lock);
+		if (trylock)
+			break; /* OK */
+
+		/* re-lock for avoiding ABBA deadlock */
+		snd_pcm_stream_unlock(substream);
+		snd_pcm_group_lock(group, nonatomic);
+		snd_pcm_stream_lock(substream);
+
+		/* check the group again; the above opens a small race window */
+		if (substream->group == group)
+			break; /* OK */
+		/* group changed, try again */
+		snd_pcm_group_unref(group, substream);
+	}
+	return group;
+}
+
 /*
  *  Note: call with stream lock
  */
@@ -1131,28 +1162,15 @@ static int snd_pcm_action(const struct action_ops *ops,
 			  struct snd_pcm_substream *substream,
 			  int state)
 {
+	struct snd_pcm_group *group;
 	int res;
 
-	if (!snd_pcm_stream_linked(substream))
-		return snd_pcm_action_single(ops, substream, state);
-
-	if (substream->pcm->nonatomic) {
-		if (!mutex_trylock(&substream->group->mutex)) {
-			mutex_unlock(&substream->self_group.mutex);
-			mutex_lock(&substream->group->mutex);
-			mutex_lock(&substream->self_group.mutex);
-		}
+	group = snd_pcm_stream_group_ref(substream);
+	if (group)
 		res = snd_pcm_action_group(ops, substream, state, 1);
-		mutex_unlock(&substream->group->mutex);
-	} else {
-		if (!spin_trylock(&substream->group->lock)) {
-			spin_unlock(&substream->self_group.lock);
-			spin_lock(&substream->group->lock);
-			spin_lock(&substream->self_group.lock);
-		}
-		res = snd_pcm_action_group(ops, substream, state, 1);
-		spin_unlock(&substream->group->lock);
-	}
+	else
+		res = snd_pcm_action_single(ops, substream, state);
+	snd_pcm_group_unref(group, substream);
 	return res;
 }
 
@@ -1179,6 +1197,7 @@ static int snd_pcm_action_nonatomic(const struct action_ops *ops,
 {
 	int res;
 
+	/* Guarantee the group members won't change during non-atomic action */
 	down_read(&snd_pcm_link_rwsem);
 	if (snd_pcm_stream_linked(substream))
 		res = snd_pcm_action_group(ops, substream, state, 0);
@@ -1460,29 +1479,24 @@ static const struct action_ops snd_pcm_action_suspend = {
 	.post_action = snd_pcm_post_suspend
 };
 
-/**
+/*
  * snd_pcm_suspend - trigger SUSPEND to all linked streams
  * @substream: the PCM substream
  *
  * After this call, all streams are changed to SUSPENDED state.
  *
- * Return: Zero if successful (or @substream is %NULL), or a negative error
- * code.
+ * Return: Zero if successful, or a negative error code.
  */
-int snd_pcm_suspend(struct snd_pcm_substream *substream)
+static int snd_pcm_suspend(struct snd_pcm_substream *substream)
 {
 	int err;
 	unsigned long flags;
 
-	if (! substream)
-		return 0;
-
 	snd_pcm_stream_lock_irqsave(substream, flags);
 	err = snd_pcm_action(&snd_pcm_action_suspend, substream, 0);
 	snd_pcm_stream_unlock_irqrestore(substream, flags);
 	return err;
 }
-EXPORT_SYMBOL(snd_pcm_suspend);
 
 /**
  * snd_pcm_suspend_all - trigger SUSPEND to all substreams in the given pcm
@@ -1506,6 +1520,14 @@ int snd_pcm_suspend_all(struct snd_pcm *pcm)
 			/* FIXME: the open/close code should lock this as well */
 			if (substream->runtime == NULL)
 				continue;
+
+			/*
+			 * Skip BE dai link PCM's that are internal and may
+			 * not have their substream ops set.
+			 */
+			if (!substream->ops)
+				continue;
+
 			err = snd_pcm_suspend(substream);
 			if (err < 0 && err != -EBUSY)
 				return err;
@@ -1792,8 +1814,6 @@ static const struct action_ops snd_pcm_action_drain_init = {
 	.post_action = snd_pcm_post_drain_init
 };
 
-static int snd_pcm_drop(struct snd_pcm_substream *substream);
-
 /*
  * Drain the stream(s).
  * When the substream is linked, sync until the draining of all playback streams
@@ -1807,6 +1827,7 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream,
 	struct snd_card *card;
 	struct snd_pcm_runtime *runtime;
 	struct snd_pcm_substream *s;
+	struct snd_pcm_group *group;
 	wait_queue_entry_t wait;
 	int result = 0;
 	int nonblock = 0;
@@ -1823,7 +1844,6 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream,
 	} else if (substream->f_flags & O_NONBLOCK)
 		nonblock = 1;
 
-	down_read(&snd_pcm_link_rwsem);
 	snd_pcm_stream_lock_irq(substream);
 	/* resume pause */
 	if (runtime->status->state == SNDRV_PCM_STATE_PAUSED)
@@ -1848,6 +1868,7 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream,
 		}
 		/* find a substream to drain */
 		to_check = NULL;
+		group = snd_pcm_stream_group_ref(substream);
 		snd_pcm_group_for_each_entry(s, substream) {
 			if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
 				continue;
@@ -1857,12 +1878,12 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream,
 				break;
 			}
 		}
+		snd_pcm_group_unref(group, substream);
 		if (!to_check)
 			break; /* all drained */
 		init_waitqueue_entry(&wait, current);
 		add_wait_queue(&to_check->sleep, &wait);
 		snd_pcm_stream_unlock_irq(substream);
-		up_read(&snd_pcm_link_rwsem);
 		if (runtime->no_period_wakeup)
 			tout = MAX_SCHEDULE_TIMEOUT;
 		else {
@@ -1874,9 +1895,17 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream,
 			tout = msecs_to_jiffies(tout * 1000);
 		}
 		tout = schedule_timeout_interruptible(tout);
-		down_read(&snd_pcm_link_rwsem);
+
 		snd_pcm_stream_lock_irq(substream);
-		remove_wait_queue(&to_check->sleep, &wait);
+		group = snd_pcm_stream_group_ref(substream);
+		snd_pcm_group_for_each_entry(s, substream) {
+			if (s->runtime == to_check) {
+				remove_wait_queue(&to_check->sleep, &wait);
+				break;
+			}
+		}
+		snd_pcm_group_unref(group, substream);
+
 		if (card->shutdown) {
 			result = -ENODEV;
 			break;
@@ -1896,7 +1925,6 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream,
 
  unlock:
 	snd_pcm_stream_unlock_irq(substream);
-	up_read(&snd_pcm_link_rwsem);
 
 	return result;
 }
@@ -1935,13 +1963,19 @@ static int snd_pcm_drop(struct snd_pcm_substream *substream)
 static bool is_pcm_file(struct file *file)
 {
 	struct inode *inode = file_inode(file);
+	struct snd_pcm *pcm;
 	unsigned int minor;
 
 	if (!S_ISCHR(inode->i_mode) || imajor(inode) != snd_major)
 		return false;
 	minor = iminor(inode);
-	return snd_lookup_minor_data(minor, SNDRV_DEVICE_TYPE_PCM_PLAYBACK) ||
-		snd_lookup_minor_data(minor, SNDRV_DEVICE_TYPE_PCM_CAPTURE);
+	pcm = snd_lookup_minor_data(minor, SNDRV_DEVICE_TYPE_PCM_PLAYBACK);
+	if (!pcm)
+		pcm = snd_lookup_minor_data(minor, SNDRV_DEVICE_TYPE_PCM_CAPTURE);
+	if (!pcm)
+		return false;
+	snd_card_unref(pcm->card);
+	return true;
 }
 
 /*
@@ -1952,7 +1986,8 @@ static int snd_pcm_link(struct snd_pcm_substream *substream, int fd)
 	int res = 0;
 	struct snd_pcm_file *pcm_file;
 	struct snd_pcm_substream *substream1;
-	struct snd_pcm_group *group;
+	struct snd_pcm_group *group, *target_group;
+	bool nonatomic = substream->pcm->nonatomic;
 	struct fd f = fdget(fd);
 
 	if (!f.file)
@@ -1963,13 +1998,14 @@ static int snd_pcm_link(struct snd_pcm_substream *substream, int fd)
 	}
 	pcm_file = f.file->private_data;
 	substream1 = pcm_file->substream;
-	group = kmalloc(sizeof(*group), GFP_KERNEL);
+	group = kzalloc(sizeof(*group), GFP_KERNEL);
 	if (!group) {
 		res = -ENOMEM;
 		goto _nolock;
 	}
-	down_write_nonfifo(&snd_pcm_link_rwsem);
-	write_lock_irq(&snd_pcm_link_rwlock);
+	snd_pcm_group_init(group);
+
+	down_write(&snd_pcm_link_rwsem);
 	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN ||
 	    substream->runtime->status->state != substream1->runtime->status->state ||
 	    substream->pcm->nonatomic != substream1->pcm->nonatomic) {
@@ -1980,23 +2016,23 @@ static int snd_pcm_link(struct snd_pcm_substream *substream, int fd)
 		res = -EALREADY;
 		goto _end;
 	}
+
+	snd_pcm_stream_lock_irq(substream);
 	if (!snd_pcm_stream_linked(substream)) {
-		substream->group = group;
-		group = NULL;
-		spin_lock_init(&substream->group->lock);
-		mutex_init(&substream->group->mutex);
-		INIT_LIST_HEAD(&substream->group->substreams);
-		list_add_tail(&substream->link_list, &substream->group->substreams);
-		substream->group->count = 1;
-	}
-	list_add_tail(&substream1->link_list, &substream->group->substreams);
-	substream->group->count++;
-	substream1->group = substream->group;
+		snd_pcm_group_assign(substream, group);
+		group = NULL; /* assigned, don't free this one below */
+	}
+	target_group = substream->group;
+	snd_pcm_stream_unlock_irq(substream);
+
+	snd_pcm_group_lock_irq(target_group, nonatomic);
+	snd_pcm_stream_lock(substream1);
+	snd_pcm_group_assign(substream1, target_group);
+	snd_pcm_stream_unlock(substream1);
+	snd_pcm_group_unlock_irq(target_group, nonatomic);
  _end:
-	write_unlock_irq(&snd_pcm_link_rwlock);
 	up_write(&snd_pcm_link_rwsem);
  _nolock:
-	snd_card_unref(substream1->pcm->card);
 	kfree(group);
  _badf:
 	fdput(f);
@@ -2005,34 +2041,43 @@ static int snd_pcm_link(struct snd_pcm_substream *substream, int fd)
 
 static void relink_to_local(struct snd_pcm_substream *substream)
 {
-	substream->group = &substream->self_group;
-	INIT_LIST_HEAD(&substream->self_group.substreams);
-	list_add_tail(&substream->link_list, &substream->self_group.substreams);
+	snd_pcm_stream_lock(substream);
+	snd_pcm_group_assign(substream, &substream->self_group);
+	snd_pcm_stream_unlock(substream);
 }
 
 static int snd_pcm_unlink(struct snd_pcm_substream *substream)
 {
-	struct snd_pcm_substream *s;
+	struct snd_pcm_group *group;
+	bool nonatomic = substream->pcm->nonatomic;
+	bool do_free = false;
 	int res = 0;
 
-	down_write_nonfifo(&snd_pcm_link_rwsem);
-	write_lock_irq(&snd_pcm_link_rwlock);
+	down_write(&snd_pcm_link_rwsem);
+
 	if (!snd_pcm_stream_linked(substream)) {
 		res = -EALREADY;
 		goto _end;
 	}
-	list_del(&substream->link_list);
-	substream->group->count--;
-	if (substream->group->count == 1) {	/* detach the last stream, too */
-		snd_pcm_group_for_each_entry(s, substream) {
-			relink_to_local(s);
-			break;
-		}
-		kfree(substream->group);
-	}
+
+	group = substream->group;
+	snd_pcm_group_lock_irq(group, nonatomic);
+
 	relink_to_local(substream);
+
+	/* detach the last stream, too */
+	if (list_is_singular(&group->substreams)) {
+		relink_to_local(list_first_entry(&group->substreams,
+						 struct snd_pcm_substream,
+						 link_list));
+		do_free = !refcount_read(&group->refs);
+	}
+
+	snd_pcm_group_unlock_irq(group, nonatomic);
+	if (do_free)
+		kfree(group);
+
        _end:
-	write_unlock_irq(&snd_pcm_link_rwlock);
 	up_write(&snd_pcm_link_rwsem);
 	return res;
 }
@@ -2457,10 +2502,8 @@ static int snd_pcm_open_file(struct file *file,
 		return -ENOMEM;
 	}
 	pcm_file->substream = substream;
-	if (substream->ref_count == 1) {
-		substream->file = pcm_file;
+	if (substream->ref_count == 1)
 		substream->pcm_release = pcm_release_private;
-	}
 	file->private_data = pcm_file;
 
 	return 0;