diff --git a/sound/firewire/bebob/bebob.c b/sound/firewire/bebob/bebob.c
index fc19c99654aa..b612599fb543 100644
--- a/sound/firewire/bebob/bebob.c
+++ b/sound/firewire/bebob/bebob.c
@@ -116,11 +116,19 @@ name_device(struct snd_bebob *bebob, unsigned int vendor_id)
 	return err;
 }
 
+/*
+ * This module releases the FireWire unit data after all ALSA character devices
+ * are released by applications. This is for releasing stream data or finishing
+ * transactions safely. Thus at returning from .remove(), this module still keep
+ * references for the unit.
+ */
 static void
 bebob_card_free(struct snd_card *card)
 {
 	struct snd_bebob *bebob = card->private_data;
 
+	fw_unit_put(bebob->unit);
+
 	if (bebob->card_index >= 0) {
 		mutex_lock(&devices_mutex);
 		clear_bit(bebob->card_index, devices_used);
@@ -205,7 +213,7 @@ bebob_probe(struct fw_unit *unit,
 	card->private_free = bebob_card_free;
 
 	bebob->card = card;
-	bebob->unit = unit;
+	bebob->unit = fw_unit_get(unit);
 	bebob->spec = spec;
 	mutex_init(&bebob->mutex);
 	spin_lock_init(&bebob->lock);
@@ -310,6 +318,8 @@ static void bebob_remove(struct fw_unit *unit)
 
 	snd_bebob_stream_destroy_duplex(bebob);
 	snd_card_disconnect(bebob->card);
+
+	/* No need to wait for releasing card object in this context. */
 	snd_card_free_when_closed(bebob->card);
 }
 
diff --git a/sound/firewire/dice/dice.c b/sound/firewire/dice/dice.c
index 90d8f40ff727..797f0726fc74 100644
--- a/sound/firewire/dice/dice.c
+++ b/sound/firewire/dice/dice.c
@@ -226,11 +226,19 @@ static void dice_card_strings(struct snd_dice *dice)
 	strcpy(card->mixername, "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
+ * transactions safely. Thus at returning from .remove(), this module still keep
+ * references for the unit.
+ */
 static void dice_card_free(struct snd_card *card)
 {
 	struct snd_dice *dice = card->private_data;
 
 	snd_dice_transaction_destroy(dice);
+	fw_unit_put(dice->unit);
+
 	mutex_destroy(&dice->mutex);
 }
 
@@ -251,7 +259,7 @@ static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
 
 	dice = card->private_data;
 	dice->card = card;
-	dice->unit = unit;
+	dice->unit = fw_unit_get(unit);
 	card->private_free = dice_card_free;
 
 	spin_lock_init(&dice->lock);
@@ -309,6 +317,7 @@ static void dice_remove(struct fw_unit *unit)
 
 	snd_dice_stream_destroy_duplex(dice);
 
+	/* No need to wait for releasing card object in this context. */
 	snd_card_free_when_closed(dice->card);
 }
 
diff --git a/sound/firewire/fireworks/fireworks.c b/sound/firewire/fireworks/fireworks.c
index 3e2ed8e82cbc..1e33394d8a93 100644
--- a/sound/firewire/fireworks/fireworks.c
+++ b/sound/firewire/fireworks/fireworks.c
@@ -173,11 +173,19 @@ get_hardware_info(struct snd_efw *efw)
 	return err;
 }
 
+/*
+ * This module releases the FireWire unit data after all ALSA character devices
+ * are released by applications. This is for releasing stream data or finishing
+ * transactions safely. Thus at returning from .remove(), this module still keep
+ * references for the unit.
+ */
 static void
 efw_card_free(struct snd_card *card)
 {
 	struct snd_efw *efw = card->private_data;
 
+	fw_unit_put(efw->unit);
+
 	if (efw->card_index >= 0) {
 		mutex_lock(&devices_mutex);
 		clear_bit(efw->card_index, devices_used);
@@ -218,7 +226,7 @@ efw_probe(struct fw_unit *unit,
 	card->private_free = efw_card_free;
 
 	efw->card = card;
-	efw->unit = unit;
+	efw->unit = fw_unit_get(unit);
 	mutex_init(&efw->mutex);
 	spin_lock_init(&efw->lock);
 	init_waitqueue_head(&efw->hwdep_wait);
@@ -293,6 +301,8 @@ static void efw_remove(struct fw_unit *unit)
 	snd_efw_transaction_remove_instance(efw);
 
 	snd_card_disconnect(efw->card);
+
+	/* No need to wait for releasing card object in this context. */
 	snd_card_free_when_closed(efw->card);
 }
 
diff --git a/sound/firewire/oxfw/oxfw.c b/sound/firewire/oxfw/oxfw.c
index 60e5cad0531a..1607b26404c3 100644
--- a/sound/firewire/oxfw/oxfw.c
+++ b/sound/firewire/oxfw/oxfw.c
@@ -104,11 +104,19 @@ static int name_card(struct snd_oxfw *oxfw)
 	return err;
 }
 
+/*
+ * This module releases the FireWire unit data after all ALSA character devices
+ * are released by applications. This is for releasing stream data or finishing
+ * transactions safely. Thus at returning from .remove(), this module still keep
+ * references for the unit.
+ */
 static void oxfw_card_free(struct snd_card *card)
 {
 	struct snd_oxfw *oxfw = card->private_data;
 	unsigned int i;
 
+	fw_unit_put(oxfw->unit);
+
 	for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
 		kfree(oxfw->tx_stream_formats[i]);
 		kfree(oxfw->rx_stream_formats[i]);
@@ -136,7 +144,7 @@ static int oxfw_probe(struct fw_unit *unit,
 	oxfw = card->private_data;
 	oxfw->card = card;
 	mutex_init(&oxfw->mutex);
-	oxfw->unit = unit;
+	oxfw->unit = fw_unit_get(unit);
 	oxfw->device_info = (const struct device_info *)id->driver_data;
 	spin_lock_init(&oxfw->lock);
 	init_waitqueue_head(&oxfw->hwdep_wait);
@@ -218,6 +226,7 @@ static void oxfw_remove(struct fw_unit *unit)
 	if (oxfw->has_output)
 		snd_oxfw_stream_destroy_simplex(oxfw, &oxfw->tx_stream);
 
+	/* No need to wait for releasing card object in this context. */
 	snd_card_free_when_closed(oxfw->card);
 }