ALSA: bebob/fireworks: simplify handling of local device entry table

In drivers of ALSA firewire stack, bebob and fireworks drivers have
local device entry table. At present, critical section to operate the
table is from the beginning/end of 'do_registration' call. This can be
more narrow and simplify codes.

This commit applies small refactoring for the above purpose.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/bebob/bebob.c

@@ -128,6 +128,10 @@ end:
 
 static void bebob_free(struct snd_bebob *bebob)
 {
+	mutex_lock(&devices_mutex);
+	clear_bit(bebob->card_index, devices_used);
+	mutex_unlock(&devices_mutex);
+
 	snd_bebob_stream_destroy_duplex(bebob);
 }
 
@@ -140,12 +144,6 @@ static void bebob_free(struct snd_bebob *bebob)
 static void
 bebob_card_free(struct snd_card *card)
 {
-	struct snd_bebob *bebob = card->private_data;
-
-	mutex_lock(&devices_mutex);
-	clear_bit(bebob->card_index, devices_used);
-	mutex_unlock(&devices_mutex);
-
 	bebob_free(card->private_data);
 }
 
@@ -186,7 +184,6 @@ do_registration(struct work_struct *work)
 		return;
 
 	mutex_lock(&devices_mutex);
-
 	for (card_index = 0; card_index < SNDRV_CARDS; card_index++) {
 		if (!test_bit(card_index, devices_used) && enable[card_index])
 			break;
@@ -202,6 +199,8 @@ do_registration(struct work_struct *work)
 		mutex_unlock(&devices_mutex);
 		return;
 	}
+	set_bit(card_index, devices_used);
+	mutex_unlock(&devices_mutex);
 
 	err = name_device(bebob);
 	if (err < 0)
@@ -242,9 +241,6 @@ do_registration(struct work_struct *work)
 	if (err < 0)
 		goto error;
 
-	set_bit(card_index, devices_used);
-	mutex_unlock(&devices_mutex);
-
 	/*
 	 * After registered, bebob instance can be released corresponding to
 	 * releasing the sound card instance.
@@ -255,7 +251,6 @@ do_registration(struct work_struct *work)
 
 	return;
 error:
-	mutex_unlock(&devices_mutex);
 	snd_bebob_stream_destroy_duplex(bebob);
 	snd_card_free(bebob->card);
 	dev_info(&bebob->unit->device,

sound/firewire/fireworks/fireworks.c

@@ -186,6 +186,10 @@ end:
 
 static void efw_free(struct snd_efw *efw)
 {
+	mutex_lock(&devices_mutex);
+	clear_bit(efw->card_index, devices_used);
+	mutex_unlock(&devices_mutex);
+
 	snd_efw_stream_destroy_duplex(efw);
 	snd_efw_transaction_remove_instance(efw);
 }
@@ -199,14 +203,6 @@ static void efw_free(struct snd_efw *efw)
 static void
 efw_card_free(struct snd_card *card)
 {
-	struct snd_efw *efw = card->private_data;
-
-	if (efw->card_index >= 0) {
-		mutex_lock(&devices_mutex);
-		clear_bit(efw->card_index, devices_used);
-		mutex_unlock(&devices_mutex);
-	}
-
 	efw_free(card->private_data);
 }
 
@@ -220,9 +216,8 @@ do_registration(struct work_struct *work)
 	if (efw->registered)
 		return;
 
-	mutex_lock(&devices_mutex);
-
 	/* check registered cards */
+	mutex_lock(&devices_mutex);
 	for (card_index = 0; card_index < SNDRV_CARDS; ++card_index) {
 		if (!test_bit(card_index, devices_used) && enable[card_index])
 			break;
@@ -238,6 +233,8 @@ do_registration(struct work_struct *work)
 		mutex_unlock(&devices_mutex);
 		return;
 	}
+	set_bit(card_index, devices_used);
+	mutex_unlock(&devices_mutex);
 
 	/* prepare response buffer */
 	snd_efw_resp_buf_size = clamp(snd_efw_resp_buf_size,
@@ -279,9 +276,6 @@ do_registration(struct work_struct *work)
 	if (err < 0)
 		goto error;
 
-	set_bit(card_index, devices_used);
-	mutex_unlock(&devices_mutex);
-
 	/*
 	 * After registered, efw instance can be released corresponding to
 	 * releasing the sound card instance.
@@ -292,7 +286,6 @@ do_registration(struct work_struct *work)
 
 	return;
 error:
-	mutex_unlock(&devices_mutex);
 	snd_efw_transaction_remove_instance(efw);
 	snd_efw_stream_destroy_duplex(efw);
 	snd_card_free(efw->card);