[ALSA] Fix auto-loading of sequencer modules

ALSA sequencer
Allow auto-loading of sequencer modules except for module init time
(which may cause blocking).
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/seq/seq.c

@@ -71,11 +71,14 @@ MODULE_PARM_DESC(seq_default_timer_resolution, "The default timer resolution in
  *  INIT PART
  */
 
+int snd_seq_in_init;
 
 static int __init alsa_seq_init(void)
 {
 	int err;
 
+	snd_seq_in_init = 1;
+
 	if ((err = client_init_data()) < 0)
 		return err;
 
@@ -99,6 +102,7 @@ static int __init alsa_seq_init(void)
 	if ((err = snd_seq_system_client_init()) < 0)
 		return err;
 
+	snd_seq_in_init = 0;
 	return 0;
 }
 

sound/core/seq/seq_clientmgr.c

@@ -152,14 +152,16 @@ client_t *snd_seq_client_use_ptr(int clientid)
 		} else if (clientid >= 64 && clientid < 128) {
 			int card = (clientid - 64) / 8;
 			if (card < snd_ecards_limit) {
+				extern int snd_seq_in_init;
 				if (! card_requested[card]) {
 					card_requested[card] = 1;
 					snd_request_card(card);
 				}
-				/* FIXME: may cause blocking when called from
-				 * module_init(), so disable this feature
+				/* Calling request_module during module_init()
+				 * may cause blocking.
 				 */
-				/* snd_seq_device_load_drivers(); */
+				if (! snd_seq_in_init)
+					snd_seq_device_load_drivers();
 			}
 		}
 		spin_lock_irqsave(&clients_lock, flags);