2 files changed, 117 insertions, 45 deletions

diff --git a/sound/firewire/dice/dice.c b/sound/firewire/dice/dice.c
index 26271cc9e9d0..b91b3739c810 100644
--- a/sound/firewire/dice/dice.c
+++ b/sound/firewire/dice/dice.c
@@ -18,6 +18,8 @@ MODULE_LICENSE("GPL v2");
 #define WEISS_CATEGORY_ID	0x00
 #define LOUD_CATEGORY_ID	0x10
 
+#define PROBE_DELAY_MS		(2 * MSEC_PER_SEC)
+
 static int check_dice_category(struct fw_unit *unit)
 {
 	struct fw_device *device = fw_parent_device(unit);
@@ -175,6 +177,16 @@ static void dice_card_strings(struct snd_dice *dice)
 	strcpy(card->mixername, "DICE");
 }
 
+static void dice_free(struct snd_dice *dice)
+{
+	snd_dice_stream_destroy_duplex(dice);
+	snd_dice_transaction_destroy(dice);
+	fw_unit_put(dice->unit);
+
+	mutex_destroy(&dice->mutex);
+	kfree(dice);
+}
+
 /*
  * This module releases the FireWire unit data after all ALSA character devices
  * are released by applications. This is for releasing stream data or finishing
@@ -183,39 +195,21 @@ static void dice_card_strings(struct snd_dice *dice)
  */
 static void dice_card_free(struct snd_card *card)
 {
-	struct snd_dice *dice = card->private_data;
-
-	snd_dice_stream_destroy_duplex(dice);
-	snd_dice_transaction_destroy(dice);
-	fw_unit_put(dice->unit);
-
-	mutex_destroy(&dice->mutex);
+	dice_free(card->private_data);
 }
 
-static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
+static void do_registration(struct work_struct *work)
 {
-	struct snd_card *card;
-	struct snd_dice *dice;
+	struct snd_dice *dice = container_of(work, struct snd_dice, dwork.work);
 	int err;
 
-	err = check_dice_category(unit);
-	if (err < 0)
-		return -ENODEV;
+	if (dice->registered)
+		return;
 
-	err = snd_card_new(&unit->device, -1, NULL, THIS_MODULE,
-			   sizeof(*dice), &card);
+	err = snd_card_new(&dice->unit->device, -1, NULL, THIS_MODULE, 0,
+			   &dice->card);
 	if (err < 0)
-		goto end;
-
-	dice = card->private_data;
-	dice->card = card;
-	dice->unit = fw_unit_get(unit);
-	card->private_free = dice_card_free;
-
-	spin_lock_init(&dice->lock);
-	mutex_init(&dice->mutex);
-	init_completion(&dice->clock_accepted);
-	init_waitqueue_head(&dice->hwdep_wait);
+		return;
 
 	err = snd_dice_transaction_init(dice);
 	if (err < 0)
@@ -227,56 +221,131 @@ static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
 
 	dice_card_strings(dice);
 
+	snd_dice_create_proc(dice);
+
 	err = snd_dice_create_pcm(dice);
 	if (err < 0)
 		goto error;
 
-	err = snd_dice_create_hwdep(dice);
+	err = snd_dice_create_midi(dice);
 	if (err < 0)
 		goto error;
 
-	snd_dice_create_proc(dice);
-
-	err = snd_dice_create_midi(dice);
+	err = snd_dice_create_hwdep(dice);
 	if (err < 0)
 		goto error;
 
-	err = snd_dice_stream_init_duplex(dice);
+	err = snd_card_register(dice->card);
 	if (err < 0)
 		goto error;
 
-	err = snd_card_register(card);
+	/*
+	 * After registered, dice instance can be released corresponding to
+	 * releasing the sound card instance.
+	 */
+	dice->card->private_free = dice_card_free;
+	dice->card->private_data = dice;
+	dice->registered = true;
+
+	return;
+error:
+	snd_dice_transaction_destroy(dice);
+	snd_card_free(dice->card);
+	dev_info(&dice->unit->device,
+		 "Sound card registration failed: %d\n", err);
+}
+
+static void schedule_registration(struct snd_dice *dice)
+{
+	struct fw_card *fw_card = fw_parent_device(dice->unit)->card;
+	u64 now, delay;
+
+	now = get_jiffies_64();
+	delay = fw_card->reset_jiffies + msecs_to_jiffies(PROBE_DELAY_MS);
+
+	if (time_after64(delay, now))
+		delay -= now;
+	else
+		delay = 0;
+
+	mod_delayed_work(system_wq, &dice->dwork, delay);
+}
+
+static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
+{
+	struct snd_dice *dice;
+	int err;
+
+	err = check_dice_category(unit);
+	if (err < 0)
+		return -ENODEV;
+
+	/* Allocate this independent of sound card instance. */
+	dice = kzalloc(sizeof(struct snd_dice), GFP_KERNEL);
+	if (dice == NULL)
+		return -ENOMEM;
+
+	dice->unit = fw_unit_get(unit);
+	dev_set_drvdata(&unit->device, dice);
+
+	spin_lock_init(&dice->lock);
+	mutex_init(&dice->mutex);
+	init_completion(&dice->clock_accepted);
+	init_waitqueue_head(&dice->hwdep_wait);
+
+	err = snd_dice_stream_init_duplex(dice);
 	if (err < 0) {
-		snd_dice_stream_destroy_duplex(dice);
-		goto error;
+		dice_free(dice);
+		return err;
 	}
 
-	dev_set_drvdata(&unit->device, dice);
-end:
-	return err;
-error:
-	snd_card_free(card);
-	return err;
+	/* Allocate and register this sound card later. */
+	INIT_DEFERRABLE_WORK(&dice->dwork, do_registration);
+	schedule_registration(dice);
+
+	return 0;
 }
 
 static void dice_remove(struct fw_unit *unit)
 {
 	struct snd_dice *dice = dev_get_drvdata(&unit->device);
 
-	/* No need to wait for releasing card object in this context. */
-	snd_card_free_when_closed(dice->card);
+	/*
+	 * Confirm to stop the work for registration before the sound card is
+	 * going to be released. The work is not scheduled again because bus
+	 * reset handler is not called anymore.
+	 */
+	cancel_delayed_work_sync(&dice->dwork);
+
+	if (dice->registered) {
+		/* No need to wait for releasing card object in this context. */
+		snd_card_free_when_closed(dice->card);
+	} else {
+		/* Don't forget this case. */
+		dice_free(dice);
+	}
 }
 
 static void dice_bus_reset(struct fw_unit *unit)
 {
 	struct snd_dice *dice = dev_get_drvdata(&unit->device);
 
+	/* Postpone a workqueue for deferred registration. */
+	if (!dice->registered)
+		schedule_registration(dice);
+
 	/* The handler address register becomes initialized. */
 	snd_dice_transaction_reinit(dice);
 
-	mutex_lock(&dice->mutex);
-	snd_dice_stream_update_duplex(dice);
-	mutex_unlock(&dice->mutex);
+	/*
+	 * After registration, userspace can start packet streaming, then this
+	 * code block works fine.
+	 */
+	if (dice->registered) {
+		mutex_lock(&dice->mutex);
+		snd_dice_stream_update_duplex(dice);
+		mutex_unlock(&dice->mutex);
+	}
 }
 
 #define DICE_INTERFACE	0x000001
diff --git a/sound/firewire/dice/dice.h b/sound/firewire/dice/dice.h
index 101550ac1a24..3d5ebebe61ea 100644
--- a/sound/firewire/dice/dice.h
+++ b/sound/firewire/dice/dice.h
@@ -45,6 +45,9 @@ struct snd_dice {
 	spinlock_t lock;
 	struct mutex mutex;
 
+	bool registered;
+	struct delayed_work dwork;
+
 	/* Offsets for sub-addresses */
 	unsigned int global_offset;
 	unsigned int rx_offset;