[PATCH] lockdep: annotate sound/core/seq/seq_ports.c

Teach special (recursive) locking code to the lock validator.  Has no effect
on non-lockdep kernels.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jaroslav Kysela <perex@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

sound/core/seq/seq_ports.c

@@ -514,7 +514,7 @@ int snd_seq_port_connect(struct snd_seq_client *connector,
 	atomic_set(&subs->ref_count, 2);
 
 	down_write(&src->list_mutex);
-	down_write(&dest->list_mutex);
+	down_write_nested(&dest->list_mutex, SINGLE_DEPTH_NESTING);
 
 	exclusive = info->flags & SNDRV_SEQ_PORT_SUBS_EXCLUSIVE ? 1 : 0;
 	err = -EBUSY;
@@ -587,7 +587,7 @@ int snd_seq_port_disconnect(struct snd_seq_client *connector,
 	unsigned long flags;
 
 	down_write(&src->list_mutex);
-	down_write(&dest->list_mutex);
+	down_write_nested(&dest->list_mutex, SINGLE_DEPTH_NESTING);
 
 	/* look for the connection */
 	list_for_each(p, &src->list_head) {