ALSA: fireworks/bebob/dice/oxfw: add reference-counting for FireWire unit

[people/ms/linux.git] / sound / firewire / dice / dice.c

diff --git a/sound/firewire/dice/dice.c b/sound/firewire/dice/dice.c
index 90d8f40ff72712f2ac67dc8f978855d59fd5f8d6..797f0726fc74467d25b127d11d6923aa7469c283 100644 (file)
--- 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);
 }