Merge branch 'topic/core-fixes' into for-linus

4 files changed, 239 insertions, 146 deletions

diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index f75d1656272c..795437b10082 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -942,31 +942,36 @@ static long snd_rawmidi_kernel_read1(struct snd_rawmidi_substream *substream,
 	unsigned long flags;
 	long result = 0, count1;
 	struct snd_rawmidi_runtime *runtime = substream->runtime;
+	unsigned long appl_ptr;
 
+	spin_lock_irqsave(&runtime->lock, flags);
 	while (count > 0 && runtime->avail) {
 		count1 = runtime->buffer_size - runtime->appl_ptr;
 		if (count1 > count)
 			count1 = count;
-		spin_lock_irqsave(&runtime->lock, flags);
 		if (count1 > (int)runtime->avail)
 			count1 = runtime->avail;
+
+		/* update runtime->appl_ptr before unlocking for userbuf */
+		appl_ptr = runtime->appl_ptr;
+		runtime->appl_ptr += count1;
+		runtime->appl_ptr %= runtime->buffer_size;
+		runtime->avail -= count1;
+
 		if (kernelbuf)
-			memcpy(kernelbuf + result, runtime->buffer + runtime->appl_ptr, count1);
+			memcpy(kernelbuf + result, runtime->buffer + appl_ptr, count1);
 		if (userbuf) {
 			spin_unlock_irqrestore(&runtime->lock, flags);
 			if (copy_to_user(userbuf + result,
-					 runtime->buffer + runtime->appl_ptr, count1)) {
+					 runtime->buffer + appl_ptr, count1)) {
 				return result > 0 ? result : -EFAULT;
 			}
 			spin_lock_irqsave(&runtime->lock, flags);
 		}
-		runtime->appl_ptr += count1;
-		runtime->appl_ptr %= runtime->buffer_size;
-		runtime->avail -= count1;
-		spin_unlock_irqrestore(&runtime->lock, flags);
 		result += count1;
 		count -= count1;
 	}
+	spin_unlock_irqrestore(&runtime->lock, flags);
 	return result;
 }
 
@@ -1055,23 +1060,16 @@ int snd_rawmidi_transmit_empty(struct snd_rawmidi_substream *substream)
 EXPORT_SYMBOL(snd_rawmidi_transmit_empty);
 
 /**
- * snd_rawmidi_transmit_peek - copy data from the internal buffer
+ * __snd_rawmidi_transmit_peek - copy data from the internal buffer
  * @substream: the rawmidi substream
  * @buffer: the buffer pointer
  * @count: data size to transfer
  *
- * Copies data from the internal output buffer to the given buffer.
- *
- * Call this in the interrupt handler when the midi output is ready,
- * and call snd_rawmidi_transmit_ack() after the transmission is
- * finished.
- *
- * Return: The size of copied data, or a negative error code on failure.
+ * This is a variant of snd_rawmidi_transmit_peek() without spinlock.
  */
-int snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
+int __snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
 			      unsigned char *buffer, int count)
 {
-	unsigned long flags;
 	int result, count1;
 	struct snd_rawmidi_runtime *runtime = substream->runtime;
 
@@ -1081,7 +1079,6 @@ int snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
 		return -EINVAL;
 	}
 	result = 0;
-	spin_lock_irqsave(&runtime->lock, flags);
 	if (runtime->avail >= runtime->buffer_size) {
 		/* warning: lowlevel layer MUST trigger down the hardware */
 		goto __skip;
@@ -1106,25 +1103,47 @@ int snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
 		}
 	}
       __skip:
+	return result;
+}
+EXPORT_SYMBOL(__snd_rawmidi_transmit_peek);
+
+/**
+ * snd_rawmidi_transmit_peek - copy data from the internal buffer
+ * @substream: the rawmidi substream
+ * @buffer: the buffer pointer
+ * @count: data size to transfer
+ *
+ * Copies data from the internal output buffer to the given buffer.
+ *
+ * Call this in the interrupt handler when the midi output is ready,
+ * and call snd_rawmidi_transmit_ack() after the transmission is
+ * finished.
+ *
+ * Return: The size of copied data, or a negative error code on failure.
+ */
+int snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
+			      unsigned char *buffer, int count)
+{
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+	int result;
+	unsigned long flags;
+
+	spin_lock_irqsave(&runtime->lock, flags);
+	result = __snd_rawmidi_transmit_peek(substream, buffer, count);
 	spin_unlock_irqrestore(&runtime->lock, flags);
 	return result;
 }
 EXPORT_SYMBOL(snd_rawmidi_transmit_peek);
 
 /**
- * snd_rawmidi_transmit_ack - acknowledge the transmission
+ * __snd_rawmidi_transmit_ack - acknowledge the transmission
  * @substream: the rawmidi substream
  * @count: the transferred count
  *
- * Advances the hardware pointer for the internal output buffer with
- * the given size and updates the condition.
- * Call after the transmission is finished.
- *
- * Return: The advanced size if successful, or a negative error code on failure.
+ * This is a variant of __snd_rawmidi_transmit_ack() without spinlock.
  */
-int snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream, int count)
+int __snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream, int count)
 {
-	unsigned long flags;
 	struct snd_rawmidi_runtime *runtime = substream->runtime;
 
 	if (runtime->buffer == NULL) {
@@ -1132,7 +1151,6 @@ int snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream, int count)
 			  "snd_rawmidi_transmit_ack: output is not active!!!\n");
 		return -EINVAL;
 	}
-	spin_lock_irqsave(&runtime->lock, flags);
 	snd_BUG_ON(runtime->avail + count > runtime->buffer_size);
 	runtime->hw_ptr += count;
 	runtime->hw_ptr %= runtime->buffer_size;
@@ -1142,9 +1160,32 @@ int snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream, int count)
 		if (runtime->drain || snd_rawmidi_ready(substream))
 			wake_up(&runtime->sleep);
 	}
-	spin_unlock_irqrestore(&runtime->lock, flags);
 	return count;
 }
+EXPORT_SYMBOL(__snd_rawmidi_transmit_ack);
+
+/**
+ * snd_rawmidi_transmit_ack - acknowledge the transmission
+ * @substream: the rawmidi substream
+ * @count: the transferred count
+ *
+ * Advances the hardware pointer for the internal output buffer with
+ * the given size and updates the condition.
+ * Call after the transmission is finished.
+ *
+ * Return: The advanced size if successful, or a negative error code on failure.
+ */
+int snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream, int count)
+{
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+	int result;
+	unsigned long flags;
+
+	spin_lock_irqsave(&runtime->lock, flags);
+	result = __snd_rawmidi_transmit_ack(substream, count);
+	spin_unlock_irqrestore(&runtime->lock, flags);
+	return result;
+}
 EXPORT_SYMBOL(snd_rawmidi_transmit_ack);
 
 /**
@@ -1160,12 +1201,22 @@ EXPORT_SYMBOL(snd_rawmidi_transmit_ack);
 int snd_rawmidi_transmit(struct snd_rawmidi_substream *substream,
 			 unsigned char *buffer, int count)
 {
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+	int result;
+	unsigned long flags;
+
+	spin_lock_irqsave(&runtime->lock, flags);
 	if (!substream->opened)
-		return -EBADFD;
-	count = snd_rawmidi_transmit_peek(substream, buffer, count);
-	if (count < 0)
-		return count;
-	return snd_rawmidi_transmit_ack(substream, count);
+		result = -EBADFD;
+	else {
+		count = __snd_rawmidi_transmit_peek(substream, buffer, count);
+		if (count <= 0)
+			result = count;
+		else
+			result = __snd_rawmidi_transmit_ack(substream, count);
+	}
+	spin_unlock_irqrestore(&runtime->lock, flags);
+	return result;
 }
 EXPORT_SYMBOL(snd_rawmidi_transmit);
 
@@ -1177,6 +1228,7 @@ static long snd_rawmidi_kernel_write1(struct snd_rawmidi_substream *substream,
 	unsigned long flags;
 	long count1, result;
 	struct snd_rawmidi_runtime *runtime = substream->runtime;
+	unsigned long appl_ptr;
 
 	if (!kernelbuf && !userbuf)
 		return -EINVAL;
@@ -1197,12 +1249,19 @@ static long snd_rawmidi_kernel_write1(struct snd_rawmidi_substream *substream,
 			count1 = count;
 		if (count1 > (long)runtime->avail)
 			count1 = runtime->avail;
+
+		/* update runtime->appl_ptr before unlocking for userbuf */
+		appl_ptr = runtime->appl_ptr;
+		runtime->appl_ptr += count1;
+		runtime->appl_ptr %= runtime->buffer_size;
+		runtime->avail -= count1;
+
 		if (kernelbuf)
-			memcpy(runtime->buffer + runtime->appl_ptr,
+			memcpy(runtime->buffer + appl_ptr,
 			       kernelbuf + result, count1);
 		else if (userbuf) {
 			spin_unlock_irqrestore(&runtime->lock, flags);
-			if (copy_from_user(runtime->buffer + runtime->appl_ptr,
+			if (copy_from_user(runtime->buffer + appl_ptr,
 					   userbuf + result, count1)) {
 				spin_lock_irqsave(&runtime->lock, flags);
 				result = result > 0 ? result : -EFAULT;
@@ -1210,9 +1269,6 @@ static long snd_rawmidi_kernel_write1(struct snd_rawmidi_substream *substream,
 			}
 			spin_lock_irqsave(&runtime->lock, flags);
 		}
-		runtime->appl_ptr += count1;
-		runtime->appl_ptr %= runtime->buffer_size;
-		runtime->avail -= count1;
 		result += count1;
 		count -= count1;
 	}
diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c
index 13cfa815732d..58e79e02f217 100644
--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -678,6 +678,9 @@ static int deliver_to_subscribers(struct snd_seq_client *client,
 	else
 		down_read(&grp->list_mutex);
 	list_for_each_entry(subs, &grp->list_head, src_list) {
+		/* both ports ready? */
+		if (atomic_read(&subs->ref_count) != 2)
+			continue;
 		event->dest = subs->info.dest;
 		if (subs->info.flags & SNDRV_SEQ_PORT_SUBS_TIMESTAMP)
 			/* convert time according to flag with subscription */
diff --git a/sound/core/seq/seq_ports.c b/sound/core/seq/seq_ports.c
index 55170a20ae72..921fb2bd8fad 100644
--- a/sound/core/seq/seq_ports.c
+++ b/sound/core/seq/seq_ports.c
@@ -173,10 +173,6 @@ struct snd_seq_client_port *snd_seq_create_port(struct snd_seq_client *client,
 }
 
 /* */
-enum group_type {
-	SRC_LIST, DEST_LIST
-};
-
 static int subscribe_port(struct snd_seq_client *client,
 			  struct snd_seq_client_port *port,
 			  struct snd_seq_port_subs_info *grp,
@@ -203,6 +199,20 @@ static struct snd_seq_client_port *get_client_port(struct snd_seq_addr *addr,
 	return NULL;
 }
 
+static void delete_and_unsubscribe_port(struct snd_seq_client *client,
+					struct snd_seq_client_port *port,
+					struct snd_seq_subscribers *subs,
+					bool is_src, bool ack);
+
+static inline struct snd_seq_subscribers *
+get_subscriber(struct list_head *p, bool is_src)
+{
+	if (is_src)
+		return list_entry(p, struct snd_seq_subscribers, src_list);
+	else
+		return list_entry(p, struct snd_seq_subscribers, dest_list);
+}
+
 /*
  * remove all subscribers on the list
  * this is called from port_delete, for each src and dest list.
@@ -210,7 +220,7 @@ static struct snd_seq_client_port *get_client_port(struct snd_seq_addr *addr,
 static void clear_subscriber_list(struct snd_seq_client *client,
 				  struct snd_seq_client_port *port,
 				  struct snd_seq_port_subs_info *grp,
-				  int grptype)
+				  int is_src)
 {
 	struct list_head *p, *n;
 
@@ -219,15 +229,13 @@ static void clear_subscriber_list(struct snd_seq_client *client,
 		struct snd_seq_client *c;
 		struct snd_seq_client_port *aport;
 
-		if (grptype == SRC_LIST) {
-			subs = list_entry(p, struct snd_seq_subscribers, src_list);
+		subs = get_subscriber(p, is_src);
+		if (is_src)
 			aport = get_client_port(&subs->info.dest, &c);
-		} else {
-			subs = list_entry(p, struct snd_seq_subscribers, dest_list);
+		else
 			aport = get_client_port(&subs->info.sender, &c);
-		}
-		list_del(p);
-		unsubscribe_port(client, port, grp, &subs->info, 0);
+		delete_and_unsubscribe_port(client, port, subs, is_src, false);
+
 		if (!aport) {
 			/* looks like the connected port is being deleted.
 			 * we decrease the counter, and when both ports are deleted
@@ -235,21 +243,14 @@ static void clear_subscriber_list(struct snd_seq_client *client,
 			 */
 			if (atomic_dec_and_test(&subs->ref_count))
 				kfree(subs);
-		} else {
-			/* ok we got the connected port */
-			struct snd_seq_port_subs_info *agrp;
-			agrp = (grptype == SRC_LIST) ? &aport->c_dest : &aport->c_src;
-			down_write(&agrp->list_mutex);
-			if (grptype == SRC_LIST)
-				list_del(&subs->dest_list);
-			else
-				list_del(&subs->src_list);
-			up_write(&agrp->list_mutex);
-			unsubscribe_port(c, aport, agrp, &subs->info, 1);
-			kfree(subs);
-			snd_seq_port_unlock(aport);
-			snd_seq_client_unlock(c);
+			continue;
 		}
+
+		/* ok we got the connected port */
+		delete_and_unsubscribe_port(c, aport, subs, !is_src, true);
+		kfree(subs);
+		snd_seq_port_unlock(aport);
+		snd_seq_client_unlock(c);
 	}
 }
 
@@ -262,8 +263,8 @@ static int port_delete(struct snd_seq_client *client,
 	snd_use_lock_sync(&port->use_lock); 
 
 	/* clear subscribers info */
-	clear_subscriber_list(client, port, &port->c_src, SRC_LIST);
-	clear_subscriber_list(client, port, &port->c_dest, DEST_LIST);
+	clear_subscriber_list(client, port, &port->c_src, true);
+	clear_subscriber_list(client, port, &port->c_dest, false);
 
 	if (port->private_free)
 		port->private_free(port->private_data);
@@ -479,85 +480,120 @@ static int match_subs_info(struct snd_seq_port_subscribe *r,
 	return 0;
 }
 
-
-/* connect two ports */
-int snd_seq_port_connect(struct snd_seq_client *connector,
-			 struct snd_seq_client *src_client,
-			 struct snd_seq_client_port *src_port,
-			 struct snd_seq_client *dest_client,
-			 struct snd_seq_client_port *dest_port,
-			 struct snd_seq_port_subscribe *info)
+static int check_and_subscribe_port(struct snd_seq_client *client,
+				    struct snd_seq_client_port *port,
+				    struct snd_seq_subscribers *subs,
+				    bool is_src, bool exclusive, bool ack)
 {
-	struct snd_seq_port_subs_info *src = &src_port->c_src;
-	struct snd_seq_port_subs_info *dest = &dest_port->c_dest;
-	struct snd_seq_subscribers *subs, *s;
-	int err, src_called = 0;
-	unsigned long flags;
-	int exclusive;
+	struct snd_seq_port_subs_info *grp;
+	struct list_head *p;
+	struct snd_seq_subscribers *s;
+	int err;
 
-	subs = kzalloc(sizeof(*subs), GFP_KERNEL);
-	if (! subs)
-		return -ENOMEM;
-
-	subs->info = *info;
-	atomic_set(&subs->ref_count, 2);
-
-	down_write(&src->list_mutex);
-	down_write_nested(&dest->list_mutex, SINGLE_DEPTH_NESTING);
-
-	exclusive = info->flags & SNDRV_SEQ_PORT_SUBS_EXCLUSIVE ? 1 : 0;
+	grp = is_src ? &port->c_src : &port->c_dest;
 	err = -EBUSY;
+	down_write(&grp->list_mutex);
 	if (exclusive) {
-		if (! list_empty(&src->list_head) || ! list_empty(&dest->list_head))
+		if (!list_empty(&grp->list_head))
 			goto __error;
 	} else {
-		if (src->exclusive || dest->exclusive)
+		if (grp->exclusive)
 			goto __error;
 		/* check whether already exists */
-		list_for_each_entry(s, &src->list_head, src_list) {
-			if (match_subs_info(info, &s->info))
-				goto __error;
-		}
-		list_for_each_entry(s, &dest->list_head, dest_list) {
-			if (match_subs_info(info, &s->info))
+		list_for_each(p, &grp->list_head) {
+			s = get_subscriber(p, is_src);
+			if (match_subs_info(&subs->info, &s->info))
 				goto __error;
 		}
 	}
 
-	if ((err = subscribe_port(src_client, src_port, src, info,
-				  connector->number != src_client->number)) < 0)
-		goto __error;
-	src_called = 1;
-
-	if ((err = subscribe_port(dest_client, dest_port, dest, info,
-				  connector->number != dest_client->number)) < 0)
+	err = subscribe_port(client, port, grp, &subs->info, ack);
+	if (err < 0) {
+		grp->exclusive = 0;
 		goto __error;
+	}
 
 	/* add to list */
-	write_lock_irqsave(&src->list_lock, flags);
-	// write_lock(&dest->list_lock); // no other lock yet
-	list_add_tail(&subs->src_list, &src->list_head);
-	list_add_tail(&subs->dest_list, &dest->list_head);
-	// write_unlock(&dest->list_lock); // no other lock yet
-	write_unlock_irqrestore(&src->list_lock, flags);
+	write_lock_irq(&grp->list_lock);
+	if (is_src)
+		list_add_tail(&subs->src_list, &grp->list_head);
+	else
+		list_add_tail(&subs->dest_list, &grp->list_head);
+	grp->exclusive = exclusive;
+	atomic_inc(&subs->ref_count);
+	write_unlock_irq(&grp->list_lock);
+	err = 0;
+
+ __error:
+	up_write(&grp->list_mutex);
+	return err;
+}
 
-	src->exclusive = dest->exclusive = exclusive;
+static void delete_and_unsubscribe_port(struct snd_seq_client *client,
+					struct snd_seq_client_port *port,
+					struct snd_seq_subscribers *subs,
+					bool is_src, bool ack)
+{
+	struct snd_seq_port_subs_info *grp;
+
+	grp = is_src ? &port->c_src : &port->c_dest;
+	down_write(&grp->list_mutex);
+	write_lock_irq(&grp->list_lock);
+	if (is_src)
+		list_del(&subs->src_list);
+	else
+		list_del(&subs->dest_list);
+	grp->exclusive = 0;
+	write_unlock_irq(&grp->list_lock);
+	up_write(&grp->list_mutex);
+
+	unsubscribe_port(client, port, grp, &subs->info, ack);
+}
+
+/* connect two ports */
+int snd_seq_port_connect(struct snd_seq_client *connector,
+			 struct snd_seq_client *src_client,
+			 struct snd_seq_client_port *src_port,
+			 struct snd_seq_client *dest_client,
+			 struct snd_seq_client_port *dest_port,
+			 struct snd_seq_port_subscribe *info)
+{
+	struct snd_seq_subscribers *subs;
+	bool exclusive;
+	int err;
+
+	subs = kzalloc(sizeof(*subs), GFP_KERNEL);
+	if (!subs)
+		return -ENOMEM;
+
+	subs->info = *info;
+	atomic_set(&subs->ref_count, 0);
+	INIT_LIST_HEAD(&subs->src_list);
+	INIT_LIST_HEAD(&subs->dest_list);
+
+	exclusive = !!(info->flags & SNDRV_SEQ_PORT_SUBS_EXCLUSIVE);
+
+	err = check_and_subscribe_port(src_client, src_port, subs, true,
+				       exclusive,
+				       connector->number != src_client->number);
+	if (err < 0)
+		goto error;
+	err = check_and_subscribe_port(dest_client, dest_port, subs, false,
+				       exclusive,
+				       connector->number != dest_client->number);
+	if (err < 0)
+		goto error_dest;
 
-	up_write(&dest->list_mutex);
-	up_write(&src->list_mutex);
 	return 0;
 
- __error:
-	if (src_called)
-		unsubscribe_port(src_client, src_port, src, info,
-				 connector->number != src_client->number);
+ error_dest:
+	delete_and_unsubscribe_port(src_client, src_port, subs, true,
+				    connector->number != src_client->number);
+ error:
 	kfree(subs);
-	up_write(&dest->list_mutex);
-	up_write(&src->list_mutex);
 	return err;
 }
 
-
 /* remove the connection */
 int snd_seq_port_disconnect(struct snd_seq_client *connector,
 			    struct snd_seq_client *src_client,
@@ -567,37 +603,28 @@ int snd_seq_port_disconnect(struct snd_seq_client *connector,
 			    struct snd_seq_port_subscribe *info)
 {
 	struct snd_seq_port_subs_info *src = &src_port->c_src;
-	struct snd_seq_port_subs_info *dest = &dest_port->c_dest;
 	struct snd_seq_subscribers *subs;
 	int err = -ENOENT;
-	unsigned long flags;
 
 	down_write(&src->list_mutex);
-	down_write_nested(&dest->list_mutex, SINGLE_DEPTH_NESTING);
-
 	/* look for the connection */
 	list_for_each_entry(subs, &src->list_head, src_list) {
 		if (match_subs_info(info, &subs->info)) {
-			write_lock_irqsave(&src->list_lock, flags);
-			// write_lock(&dest->list_lock);  // no lock yet
-			list_del(&subs->src_list);
-			list_del(&subs->dest_list);
-			// write_unlock(&dest->list_lock);
-			write_unlock_irqrestore(&src->list_lock, flags);
-			src->exclusive = dest->exclusive = 0;
-			unsubscribe_port(src_client, src_port, src, info,
-					 connector->number != src_client->number);
-			unsubscribe_port(dest_client, dest_port, dest, info,
-					 connector->number != dest_client->number);
-			kfree(subs);
+			atomic_dec(&subs->ref_count); /* mark as not ready */
 			err = 0;
 			break;
 		}
 	}
-
-	up_write(&dest->list_mutex);
 	up_write(&src->list_mutex);
-	return err;
+	if (err < 0)
+		return err;
+
+	delete_and_unsubscribe_port(src_client, src_port, subs, true,
+				    connector->number != src_client->number);
+	delete_and_unsubscribe_port(dest_client, dest_port, subs, false,
+				    connector->number != dest_client->number);
+	kfree(subs);
+	return 0;
 }
 
 
diff --git a/sound/core/seq/seq_virmidi.c b/sound/core/seq/seq_virmidi.c
index f71aedfb408c..c82ed3e70506 100644
--- a/sound/core/seq/seq_virmidi.c
+++ b/sound/core/seq/seq_virmidi.c
@@ -155,21 +155,26 @@ static void snd_virmidi_output_trigger(struct snd_rawmidi_substream *substream,
 	struct snd_virmidi *vmidi = substream->runtime->private_data;
 	int count, res;
 	unsigned char buf[32], *pbuf;
+	unsigned long flags;
 
 	if (up) {
 		vmidi->trigger = 1;
 		if (vmidi->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH &&
 		    !(vmidi->rdev->flags & SNDRV_VIRMIDI_SUBSCRIBE)) {
-			snd_rawmidi_transmit_ack(substream, substream->runtime->buffer_size - substream->runtime->avail);
-			return;		/* ignored */
+			while (snd_rawmidi_transmit(substream, buf,
+						    sizeof(buf)) > 0) {
+				/* ignored */
+			}
+			return;
 		}
 		if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
 			if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
 				return;
 			vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
 		}
+		spin_lock_irqsave(&substream->runtime->lock, flags);
 		while (1) {
-			count = snd_rawmidi_transmit_peek(substream, buf, sizeof(buf));
+			count = __snd_rawmidi_transmit_peek(substream, buf, sizeof(buf));
 			if (count <= 0)
 				break;
 			pbuf = buf;
@@ -179,16 +184,18 @@ static void snd_virmidi_output_trigger(struct snd_rawmidi_substream *substream,
 					snd_midi_event_reset_encode(vmidi->parser);
 					continue;
 				}
-				snd_rawmidi_transmit_ack(substream, res);
+				__snd_rawmidi_transmit_ack(substream, res);
 				pbuf += res;
 				count -= res;
 				if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
 					if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
-						return;
+						goto out;
 					vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
 				}
 			}
 		}
+	out:
+		spin_unlock_irqrestore(&substream->runtime->lock, flags);
 	} else {
 		vmidi->trigger = 0;
 	}